117 research outputs found

    Black Perspectives on Creativity, Trustworthiness, Welcome and Well-Being--Findings From a Qualitative Study

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    Culture + Community in a Time of Transformation: A Special Edition of Culture Track is a collaborative effort to keep the cultural sector in dialogue with its communities and participants during the pandemic and inform deeper equity and justice in the years to come. The project pivoted from examining public attitudes and behaviors in a "time of crisis" in 2020 to doing so in a "time of transformation" in 2021, with a crucial focus around racialized experiences in connection with cultural participation and cultural organizations.The first phase of the research, conducted in Spring 2020, was a large-scale survey intended to inform not just resilience but also innovation and progress toward equity in the cultural sector, and to give the U.S. public a voice in the future of cultural engagement. But that first phase was designed and conducted before the murder of George Floyd ignited a national upswell of anger, sadness, and activism and the Movement for Black Lives began to reshape the discourse around racism in every aspect of American life. In a follow-up statistical analysis of the same (early 2020) data published in December as "Centering the Picture," we and our colleagues explored respondents' experiences in relation to their racial and ethnic identities to highlight and amplify what people of color have been going through and what they would like to see changed in the future. The report revealed some unique experiences and perspectives that Black and African American adults in the U.S. have in relation to cultural engagement, digital connection with arts and culture, and social change. The Slover Linett team, knowing that qualitative methods would be necessary to understand those perspectives in a more nuanced and holistic way, advocated for an additional phase of research in 2021 that would offer a triangulation with β€” as well as departure point from β€” the twowave quantitative survey.To that end, and in order to authentically amplify Black voices and stories, we dedicated this qualitative phase of the research solely to Black and African American participants' perspectives, since those viewpoints have historically been excluded or sidelined in most research studies and planning efforts in the cultural field. We intentionally took a broad approach to this inquiry, exploring general dynamics of creativity, trustworthiness, welcome, and community support rather than focusing narrowly on arts and culture organizations and attendance. This allowed us to hear and explore how culture and community experiences and organizations naturally fit into peoples' lives, and it led to rich insights that can inform practice, funding, and policy

    Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure

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    Sperandio PA, Oliveira MF, Rodrigues MK, Berton DC, Treptow E, Nery LE, Almeida DR, Neder JA. Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure. Am J Physiol Heart Circ Physiol 303: H1474-H1480, 2012. First published September 28, 2012; doi:10.1152/ajpheart.00435.2012.-Nitric oxide (NO) can temporally and spatially match microvascular oxygen (O-2) delivery (QO(2mv)) to O-2 uptake (VO2) in the skeletal muscle, a crucial adjustment-to-exercise tolerance that is impaired in chronic heart failure (CHF). To investigate the effects of NO bioavailability induced by sildenafil intake on muscle QO(2mv)-to-O-2 utilization matching and VO2 kinetics, 10 males with CHF (ejection fraction = 27 +/- 6%) undertook constant work-rate exercise (70-80% peak). Breath-by-breath VO2, fractional O-2 extraction in the vastus lateralis {similar to deoxy-genated hemoglobin + myoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy}, and cardiac output (CO) were evaluated after sildenafil (50 mg) or placebo. Sildenafil increased exercise tolerance compared with placebo by similar to 20%, an effect that was related to faster on-and off-exercise VO2 kinetics (P 0.05). On-exercise [deoxy-Hb + Mb] kinetics were slowed by sildenafil (similar to 25%), and a subsequent response overshoot (n = 8) was significantly lessened or even abolished. in contrast, [deoxy-Hb + Mb] recovery was faster with sildenafil (similar to 15%). Improvements in muscle oxygenation with sildenafil were related to faster on-exercise VO2 kinetics, blunted oscillations in ventilation (n = 9), and greater exercise capacity (P < 0.05). Sildenafil intake enhanced intramuscular QO(2mv)-to-VO2 matching with beneficial effects on VO2 kinetics and exercise tolerance in CHF. the lack of effect on CO suggests that improvement in blood flow to and within skeletal muscles underlies these effects.Universidade Federal de SΓ£o Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 SΓ£o Paulo, BrazilQueens Univ, Dept Med, Div Resp & Crit Care Med, Kingston, ON K7L 3N6, CanadaUniversidade Federal de SΓ£o Paulo, Dept Med, Div Cardiol, BR-04020050 SΓ£o Paulo, BrazilUniversidade Federal de SΓ£o Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 SΓ£o Paulo, BrazilUniversidade Federal de SΓ£o Paulo, Dept Med, Div Cardiol, BR-04020050 SΓ£o Paulo, BrazilWeb of Scienc

    Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

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    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods A (07/31/2013

    Pain Behavior Changes Following Disc Puncture Relate to Nucleus Pulposus Rather than to the Disc Injury Per Se: An Experimental Study in Rats

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    It has previously been demonstrated that disc puncture in the rat induced changes in grooming and wet dog shakes, two behavioral changes that may be linked to discomfort and neuropathic pain. In this study the aim was to separate the effects of disc injury and the epidural presence of nucleus pulposus. Following anesthesia, the L4-5 disc was exposed using a dorsal approach. Ten rats received a superficial disc injury without nucleus pulposus leakage and ten rats received nucleus pulposus from a donor rat without disc injury. In ten animals the L4-5 disc was punctured using a ventral approach, with 10 corresponding controls. Spontaneous behavior was assessed after surgery. The data was matched to historical control of dorsal sham surgery and disc puncture. The study showed that the effects of nucleus pulposus were more pronounced than the effects induced by the disc injury. Ventral disc puncture did not induce any behavioral changes different from sham exposure. In conclusion, the data from the study indicate that behavioral changes induced by disc puncture are more likely to relate to the epidural presence of nucleus pulposus than the disc injury per se

    Discovery of an Auto-Regulation Mechanism for the Maltose ABC Transporter MalFGK2

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    The maltose transporter MalFGK2, together with the substrate-binding protein MalE, is one of the best-characterized ABC transporters. In the conventional model, MalE captures maltose in the periplasm and delivers the sugar to the transporter. Here, using nanodiscs and proteoliposomes, we instead find that MalE is bound with high-affinity to MalFGK2 to facilitate the acquisition of the sugar. When the maltose concentration exceeds the transport capacity, MalE captures maltose and dissociates from the transporter. This mechanism explains why the transport rate is high when MalE has low affinity for maltose, and low when MalE has high affinity for maltose. Transporter-bound MalE facilitates the acquisition of the sugar at low concentrations, but also captures and dissociates from the transporter past a threshold maltose concentration. In vivo, this maltose-forced dissociation limits the rate of transport. Given the conservation of the substrate-binding proteins, this mode of allosteric regulation may be universal to ABC importers

    PIP2-Binding Site in Kir Channels: Definition by Multiscale Biomolecular Simulations†

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    Phosphatidylinositol bisphosphate (PIP(2)) is an activator of mammalian inwardly rectifying potassium (Kir) channels. Multiscale simulations, via a sequential combination of coarse-grained and atomistic molecular dynamics, enabled exploration of the interactions of PIP(2) molecules within the inner leaflet of a lipid bilayer membrane with possible binding sites on Kir channels. Three Kir channel structures were investigated: X-ray structures of KirBac1.1 and of a Kir3.1-KirBac1.3 chimera and a homology model of Kir6.2. Coarse-grained simulations of the Kir channels in PIP(2)-containing lipid bilayers identified the PIP(2)-binding site on each channel. These models of the PIP(2)-channel complexes were refined by conversion to an atomistic representation followed by molecular dynamics simulation in a lipid bilayer. All three channels were revealed to contain a conserved binding site at the N-terminal end of the slide (M0) helix, at the interface between adjacent subunits of the channel. This binding site agrees with mutagenesis data and is in the proximity of the site occupied by a detergent molecule in the Kir chimera channel crystal. Polar contacts in the coarse-grained simulations corresponded to long-lived electrostatic and H-bonding interactions between the channel and PIP(2) in the atomistic simulations, enabling identification of key side chains
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