696 research outputs found

    Involvement of the RNA polymerase II-associated Paf1 complex in transcriptional regulation and 3'-end formation of snoRNAs

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    Transcription elongation is an important regulatory step in the RNA polymerase II transcription cycle. Previous work from our laboratory and others strongly suggests that the Paf1 complex interacts with and regulates the activity of RNA polymerase II during transcription elongation. Affinity purification of Paf1 revealed that it exists in a complex in vivo with Ctr9, Rtf1, Cdc73 and Leo1 called the Paf1 complex. To further investigate the function of the Paf1 complex in vivo, we used a genetic approach to study the component Rtf1 and microarray analyses to identify Ctr9-regulated genes. Null mutations in RTF1 confer two phenotypes associated with defective transcription elongation, sensitivity to base analogs and the Spt- phenotype. To identify novel mutations in RTF1, we performed a genetic screen for rtf1 mutations that confer conditional mutant phenotypes. We identified three new rtf1 missense mutations. To identify proteins that functionally interact with the Paf1 complex, we performed a screen for multicopy suppressors of the rtf1 mutations. This screen identified NAB3 as a suppressor of rtf1. Nab3 interacts with the RNA polymerase II-associated hnRNP Nrd1. Together, Nrd1 and Nab3 are required for efficient 3'-end formation of certain nonpolyadenylated RNA polymerase II transcripts, including snoRNAs. Using assays to detect transcriptional readthrough of snoRNA genes, we have shown that deletion of certain Paf1 complex members causes strong defects in snoRNA 3'-end formation. By chromatin immunoprecipitation (ChIP) analysis, we have found that the Paf1 complex and Nab3 associate with snoRNA genes in vivo. In the second approach, expression analyses revealed a role for the Paf1 complex in directly regulating the expression of certain genes that are not transcribed during growth in rich media. ChIP experiments indicated that the Paf1 complex associates along the length of ARG1 and with the promoter region of SER3. Together, our results reinforce the idea that the Paf1 complex is involved in the production of mRNAs and provide evidence that the Paf1 complex also participates in snoRNA transcription and 3'-end formation during RNA polymerase II transcription

    International Trends and Techniques Used to Teach Studio Art Courses Through Distance Education

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    This research collected data about international trends and techniques used to teach studio art courses through distance learning. The study presents information about methods of curriculum and instruction, background information about teaching face-to-face art courses and transitioning to online instruction, the amount of time dedicated to online studio art courses by students and instructors, and details about educational resources and projects. The information provides ideas and methods to solve problems in art education through distance learning and speculates about the pedagogical effects of international classes.  This self-report survey was sent to online studio art instructors at postsecondary institutions in the international arena. The instructors responded to a series of statements and questions regarding trends and techniques used to teach studio art courses through distance learning. This resulted in standardized, quantifiable information from members of the focused population. Data collection method was e-mail.  Of the professors surveyed, the most successful part of teaching studio art online was listed as the ability to reach a broader population. The most frustrating part was listed as skepticism on the success of studio art taught online and students' lack of experience with technology. The majority of professors considered an international population of students to be a multicultural learning opportunity despite language barriers. Eighty-eight percent of the instructors surveyed felt that online art instruction held the potential to become more prevalent in the future because of accessibility, cost effectiveness, and technological advancements. Recommendations about techniques and trends of online studio art courses have been provided based on the research data.  M.A.Ed

    Maine Trail Visitor Count 2019 to 2021

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    Trail usage data are critical to informing decisions about investments in new trails and infrastructure, the maintenance of existing trails and infrastructure, and management of trails. Maine, like many other states, lacks detailed and consistent data on trail use, and this lack of information complicates decision-making, investments, and planning. New data and technologies create opportunities for Maine to improve knowledge of trail use, increase outdoor recreation experiences associated with these trails and strengthen the economic and community impacts of these trails. In collaboration with Maine\u27s Office of Outdoor Recreation, the Maine Bureau of Parks and Lands, and the Maine Trails Coalition, we completed this project to assess the potential for using new data resources made available by StreetLight to document trail usage in Maine

    The Role of the Immunological Synapse in Differential Effects of APC Subsets in Alloimmunization to Fresh, Non-stored RBCs

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    Background: Each year, over 5 million red blood cell (RBC) transfusions are administered to patients in the USA. Despite the therapeutic benefits of RBC transfusions, there are associated risks. RBC-specific alloantibodies may form in response to antigenic differences between RBC donors and recipients; these alloantibodies can be a problem as they may mediate hemolysis or pose barriers to future transfusion support. While there is currently no reliable way to predict which RBC recipients will make an alloantibody response, risk factors such as inflammation have been shown to correlate with increased rates of RBC alloimmunization. The underlying mechanisms behind how inflammation mediates alloantibody production are incompletely defined.Methods: To assess erythrophagocytosis, mice were treated with PBS or inflammatory stimuli followed by a transfusion of allogeneic RBCs labeled with a lipophilic dye. At multiple time points, RBC consumption and expression of activation makers by leukocytes was evaluated. To determine which antigen presenting cell (APC) subset(s) were capable of promoting allogeneic T cell activation, sorted leukocyte populations (which had participated in erythrophagocytosis) were co-cultured in vitro with allogeneic CD4+ T cells; T cell proliferation and ability to form immunological synapses with APCs were determined.Results: Upon transfusion of fresh allogeneic RBCs, multiple APCs consumed transfused RBCs. However, only CD8+ and CD11b+ dendritic cells formed productive immunological synapses with allogeneic T cells and stimulated proliferation. Importantly, allogeneic T cell activation and RBC alloantibody production occurred in response to RBC transfusion alone, and transfusion in the context of inflammation enhanced RBC consumption, the number of immune synapses, allogeneic T cell proliferation, and the rate and magnitude of alloantibody production.Conclusions: These data demonstrate that regardless of the ability to participate in RBC consumption, only a subset of APCs are capable of forming an immune synapse with T cells thereby initiating an alloantibody response. Additionally, these data provide mechanistic insight into RBC alloantibody generation

    Single cell tracking of gadolinium labeled CD4(+) T cells by laser ablation inductively coupled plasma mass spectrometry

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    Cellular therapy is emerging as a promising alternative to conventional immunosuppression in the fields of haematopoietic stem cell (HSC) transplantation, autoimmune disease and solid organ transplantation. Determining the persistence of cell-based therapies in vivo is crucial to understanding their regulatory function and requires the combination of an extremely sensitive detection technique and a stable, long-lifetime cell labelling agent. This paper reports the first application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to perform single cell detection of T cell populations relevant to cellular immunotherapy. Purified human CD4+ T cells were labelled with commercially available Gd-based MRI contrast agents, Omniscan® and Dotarem®, which enabled passive loading of up to 108 Gd atoms per cell. In mixed preparations of labelled and unlabelled cells, LA-ICP-MS was capable of enumerating labelled cells at close to the predicted ratio. More importantly, LA-ICP-MS single cell analysis demonstrated that the cells retained sufficient label to remain detectable for up to 10 days post-labelling both in vitro and in vivo in an immunodeficient mouse model

    Trauma history and depression predict incomplete adherence to antiretroviral therapies in a low income country.

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    As antiretroviral therapy (ART) for HIV becomes increasingly available in low and middle income countries (LMICs), understanding reasons for lack of adherence is critical to stemming the tide of infections and improving health. Understanding the effect of psychosocial experiences and mental health symptomatology on ART adherence can help maximize the benefit of expanded ART programs by indicating types of services, which could be offered in combination with HIV care. The Coping with HIV/AIDS in Tanzania (CHAT) study is a longitudinal cohort study in the Kilimanjaro Region that included randomly selected HIV-infected (HIV+) participants from two local hospital-based HIV clinics and four free-standing voluntary HIV counselling and testing sites. Baseline data were collected in 2008 and 2009; this paper used data from 36 month follow-up interviews (N = 468). Regression analyses were used to predict factors associated with incomplete self-reported adherence to ART. INCOMPLETE ART ADHERENCE WAS SIGNIFICANTLY MORE LIKELY TO BE REPORTED AMONGST PARTICIPANTS WHO EXPERIENCED A GREATER NUMBER OF CHILDHOOD TRAUMATIC EVENTS: sexual abuse prior to puberty and the death in childhood of an immediate family member not from suicide or homicide were significantly more likely in the non-adherent group and other negative childhood events trended toward being more likely. Those with incomplete adherence had higher depressive symptom severity and post-traumatic stress disorder (PTSD). In multivariable analyses, childhood trauma, depression, and financial sacrifice remained associated with incomplete adherence.\ud This is the first study to examine the effect of childhood trauma, depression and PTSD on HIV medication adherence in a low income country facing a significant burden of HIV. Allocating spending on HIV/AIDS toward integrating mental health services with HIV care is essential to the creation of systems that enhance medication adherence and maximize the potential of expanded antiretroviral access to improve health and reduce new infections

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Paternal attractiveness and the effects of differential allocation of parental investment

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    The differential allocation hypothesis (DAH) predicts that an individual should vary its reproductive investment according to the attractiveness of its mate. A recently revised version of the DAH makes explicit that investment can be positive, i.e. higher for the offspring of attractive males which should be of higher quality, or negative, i.e. higher for offspring of unattractive males, for example compensating for inheriting poor paternal genes. Moreover, investment can be made by the father and the mother. Here, we tested whether experimental manipulation of male attractiveness affected parental investment at different reproductive stages and thus influenced fitness-related traits in offspring. In two aviaries, all male zebra finches, Taeniopygia guttata, were given red leg rings to increase attractiveness and in two aviaries all males received green leg rings to decrease attractiveness. This controlled for assortative mating between treatments. Ring colour was merely an experimental manipulation of male attractiveness, not paternal quality, so we might expect additional investment to elevate offspring quality. Eggs were cross-fostered between and within treatments to allow differentiation of effects of investment in eggs and nestlings. Clutch and brood sizes were standardized. Both positive and negative investment were observed: Eggs from red-ringed fathers had higher yolk to albumen ratios than eggs from green-ringed fathers. Nestlings from eggs laid and incubated by parents in the red-ringed group had higher hatching masses than those in the green-ringed group. Both parents in the green-ringed group fed nestlings more frequently than red-ringed parents. Offspring performance was influenced by the treatment of both foster and biological parents, but combined effects of these different investment patterns on fitness-related traits were ambiguous. Male attractiveness appeared to affect patterns of reproductive investment but not consistently across all forms of reproductive investment suggesting that the costs and benefits of differential allocation vary among individuals and across contexts
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