339 research outputs found
Plant-Soil Microbiome Feedback Impacts on Native and Non-native Grasses Throughout Kansas
Beginning in 1917, a group of perennial warm-season bunchgrasses collectively called Old World Bluestems (OWBs) were introduced from the countries of Europe, Asia, Russia, and Australia. These grasses were brought in to reduce soil erosion and increase hay and forage production, as they can produce up to four times more biomass than native grasses. However, the forage quality of OWBs is reduced as the plant matures and must therefore be harvested prior to maturation. Furthermore, OWBs have become problematic in the southern and central Great Plains, invading and then dominating native warm-season rangelands causing a reduction in ecosystem services
Success Rate of Embolization for Type II Endoleaks at a Major Tertiary Referral Center
Objective: The rise of endovascular aneurysm repair (EVAR) as the preferred treatment for abdominal aortic aneurysm (AAA) has introduced endoleaks as a major complication following AAA repair. The objective of this study is to assess the outcomes associated with endovascular embolization of type II endoleaks after EVAR. Methods: The institutional Radiology database at our tertiary referral hospital was queried for type II endoleak during the period 2006-2018. A retrospective chart review was then carried out. Only patients who underwent intervention for isolated type 2 endoleaks were analyzed. The primary outcome was success of the endoleak repair as determined by cessation of growth (i.e., β€5mm change in diameter over follow-up period) of the native aneurysm sac. Patient outcomes for each failure of the above criterion were also collected. Other data pertaining to the location of endoleak, type of occlusion performed, type of embolic agent used, type of endograft used for EVAR, and incidence of aneurysm rupture were collected as secondary outcomes.Results:During this period 41 patients were treated for type II endoleaks. Demographics are shown in table 1. Cessation of growth was achieved in 28/41 (68.3%) of the patients after one embolization procedure. In 13/41 (31.7%) of patients, growth of the native aneurysm sac continued. Of the patients whose aneurysms continued to grow, 61.5% (8/13) did not undergo a second embolization. The remaining 38.5% (5/13) underwent a second embolization.Patient outcomes for both of these groups are presented in table II. None of the patients were found to have ruptured their aneurysm sac during follow-up after embolization. None of gender, race, the embolization site, or method of embolization were associated with embolization failure. Conclusions: Embolization of type II endoleaks is associated with a cessation of growth in the majority of cases and seems to be protective regarding the risk of aneurysm sac rupture. Future studies and additional follow-up will be important to elucidate the most significant risk factors for expansion and/or rupture of the endovascularly repaired abdominal aneurysm.Table I: Demographics for patients with type II endoleaks who underwent endovascular embolizationVariableValue Age (years +/- sd)75.66 +/- yearsAverage follow-up (months)62.65 monthsSex (%)71.7% male28.3% femaleRace (%)77.7% white17.8% black4.4% otherInflow vessel (%)43.2% lumbar only36.4% IMA only20.5% mixEmbolization site (%)40.5% vessel only14.3% cavity only20.5% mixEmbolization type (%)66.7% coil9.5% glue23.8% mixTable II: Outcomes for patients with continued growth after embolizationThose that did no undergo further embolizationThose that underwent a second embolization 3 were found to have type III endoleak and were successfully repaired with lining of the graft.2 whose aneurysm sac ceased growing. 2 who declined further treatment. 2 whose aneurysm sac continued to grow with persistent evidence of endoleak.1 who died from non-vascular complications. 1 who was lost to follow-up. 1 who is scheduled future surgical repair. 1 who was lost to follow-up.https://scholarlycommons.henryford.com/merf2019clinres/1026/thumbnail.jp
Using Devolution to Set the Agenda? Venue shift and the smoking ban in Scotland
This article examines the changing agendas on smoking-related issues in Scotland. It charts the methods that groups, governments and MSPs use to frame and pursue or suppress discussion of the prohibition of smoking in public places. The article presents two narratives-one which stresses ‘new politics' and the ability of groups to influence policy through Scottish Parliamentary procedures, and another which stresses Scottish Executive ‘business as usual' and presents smoking legislation as a logical progression from early ministerial commitments. A combination of narratives suggests that tobacco legislation in Scotland was by no means part of an inevitable international trend towards prohibition and this article traces the precise conditions or ‘policy windows' in which decisions take place. The discussion highlights the often unsettled nature of the devolution settlement and the ability of Scottish issues to influence UK agendas
A self-organized model for cell-differentiation based on variations of molecular decay rates
Systemic properties of living cells are the result of molecular dynamics
governed by so-called genetic regulatory networks (GRN). These networks capture
all possible features of cells and are responsible for the immense levels of
adaptation characteristic to living systems. At any point in time only small
subsets of these networks are active. Any active subset of the GRN leads to the
expression of particular sets of molecules (expression modes). The subsets of
active networks change over time, leading to the observed complex dynamics of
expression patterns. Understanding of this dynamics becomes increasingly
important in systems biology and medicine. While the importance of
transcription rates and catalytic interactions has been widely recognized in
modeling genetic regulatory systems, the understanding of the role of
degradation of biochemical agents (mRNA, protein) in regulatory dynamics
remains limited. Recent experimental data suggests that there exists a
functional relation between mRNA and protein decay rates and expression modes.
In this paper we propose a model for the dynamics of successions of sequences
of active subnetworks of the GRN. The model is able to reproduce key
characteristics of molecular dynamics, including homeostasis, multi-stability,
periodic dynamics, alternating activity, differentiability, and self-organized
critical dynamics. Moreover the model allows to naturally understand the
mechanism behind the relation between decay rates and expression modes. The
model explains recent experimental observations that decay-rates (or turnovers)
vary between differentiated tissue-classes at a general systemic level and
highlights the role of intracellular decay rate control mechanisms in cell
differentiation.Comment: 16 pages, 5 figure
THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE
Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managersβ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizationsβ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research
Is Scotland a Westminster-style Majoritarian Democracy or a Scandinavian-style Consensus Democracy? A Comparison of Scotland, the UK and Sweden
Peer reviewedPostprin
A combined rocket-borne and ground-based study of the sodium layer and charged dust in the upper mesosphere
The Hotel Payload 2 rocket was launched on January 31st 2008 at 20.14 LT from the AndΓΈya Rocket Range in northern Norway (69.31Β° N, 16.01Β° E). Measurements in the 75β105 km region of atomic O, negatively-charged dust, positive ions and electrons with a suite of instruments on the payload were complemented by lidar measurements of atomic Na and temperature from the nearby ALOMAR observatory. The payload passed within 2.58 km of the lidar at an altitude of 90 km. A series of coupled models is used to explore the observations, leading to two significant conclusions. First, the atomic Na layer and the vertical profiles of negatively-charged dust (assumed to be meteoric smoke particles), electrons and positive ions, can be modelled using a self-consistent meteoric input flux. Second, electronic structure calculations and RiceβRamspergerβKasselβMarkus theory are used to show that even small FeβMgβsilicates are able to attach electrons rapidly and form stable negatively-charged particles, compared with electron attachment to O2 and O3. This explains the substantial electron depletion between 80 and 90 km, where the presence of atomic O at concentrations in excess of 1010 cmβ3 prevents the formation of stable negative ions
Identifying and prioritizing strategies for comprehensive liver cancer control in Asia
<p>Abstract</p> <p>Background</p> <p>Liver cancer is both common and burdensome in Asia. Effective liver cancer control, however, is hindered by a complex etiology and a lack of coordination across clinical disciplines. We sought to identify strategies for inclusion in a comprehensive liver cancer control for Asia and to compare qualitative and quantitative methods for prioritization.</p> <p>Methods</p> <p>Qualitative interviews (N = 20) with international liver cancer experts were used to identify strategies using Interpretative Phenomenological Analysis and to formulate an initial prioritization through frequency analysis. Conjoint analysis, a quantitative stated-preference method, was then applied among Asian liver cancer experts (N = 20) who completed 12 choice tasks that divided these strategies into two mutually exclusive and exhaustive subsets. Respondents' preferred plan was the primary outcome in a choice model, estimated using ordinary least squares (OLS) and logistic regression. Priorities were then compared using Spearman's Rho.</p> <p>Results</p> <p>Eleven strategies were identified: <it>Access to treatments; Centers of excellence; Clinical education; Measuring social burden; Monitoring of at-risk populations; Multidisciplinary management; National guidelines; Public awareness; Research infrastructure; Risk-assessment and referral</it>; and <it>Transplantation infrastructure</it>. Qualitative frequency analysis indicated that <it>Risk-assessment and referral </it>(85%), <it>National guidelines </it>(80%) and <it>Monitoring of at-risk populations </it>(80%) received the highest priority, while conjoint analysis pointed to <it>Monitoring of at-risk populations </it>(p < 0.001), <it>Centers of excellence </it>(p = 0.002), and <it>Access to treatments </it>(p = 0.004) as priorities, while <it>Risk-assessment and referral </it>was the lowest priority (p = 0.645). We find moderate concordance between the qualitative and quantitative methods (rho = 0.20), albeit insignificant (p = 0.554), and a strong concordance between the OLS and logistic regressions (rho = 0.979; p < 0.0001).</p> <p>Conclusions</p> <p>Identified strategies can be conceptualized as the ABCs of comprehensive liver cancer control as they focus on <it>Antecedents</it>, <it>Better care </it>and <it>Connections </it>within a national strategy. Some concordance was found between the qualitative and quantitative methods (e.g. <it>Monitoring of at-risk populations</it>), but substantial differences were also identified (e.g. qualitative methods gave highest priority to risk-assessment and referral, but it was the lowest for the quantitative methods), which may be attributed to differences between the methods and study populations, and potential framing effects in choice tasks. Continued research will provide more generalizable estimates of priorities and account for variation across stakeholders and countries.</p
Assessing outgroup prejudice among 13β15-year-old students attending Catholic and Protestant secondary schools in Northern Ireland: An empirical enquiry
Transcription Factors Mat2 and Znf2 Operate Cellular Circuits Orchestrating Opposite- and Same-Sex Mating in Cryptococcus neoformans
Cryptococcus neoformans is a human fungal pathogen that undergoes a dimorphic transition from a unicellular yeast to multicellular hyphae during opposite sex (mating) and unisexual reproduction (same-sex mating). Opposite- and same-sex mating are induced by similar environmental conditions and involve many shared components, including the conserved pheromone sensing Cpk1 MAPK signal transduction cascade that governs the dimorphic switch in C. neoformans. However, the homeodomain cell identity proteins Sxi1Ξ±/Sxi2a encoded by the mating type locus that are essential for completion of sexual reproduction following cellβcell fusion during opposite-sex mating are dispensable for same-sex mating. Therefore, identification of downstream targets of the Cpk1 MAPK pathway holds the key to understanding molecular mechanisms governing the two distinct developmental fates. Thus far, homology-based approaches failed to identify downstream transcription factors which may therefore be species-specific. Here, we applied insertional mutagenesis via Agrobacterium-mediated transformation and transcription analysis using whole genome microarrays to identify factors involved in C. neoformans differentiation. Two transcription factors, Mat2 and Znf2, were identified as key regulators of hyphal growth during same- and opposite-sex mating. Mat2 is an HMG domain factor, and Znf2 is a zinc finger protein; neither is encoded by the mating type locus. Genetic, phenotypic, and transcriptional analyses of Mat2 and Znf2 provide evidence that Mat2 is a downstream transcription factor of the Cpk1 MAPK pathway whereas Znf2 functions as a more terminal hyphal morphogenesis determinant. Although the components of the MAPK pathway including Mat2 are not required for virulence in animal models, Znf2, as a hyphal morphology determinant, is a negative regulator of virulence. Further characterization of these elements and their target circuits will reveal genes controlling biological processes central to fungal development and virulence
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