345 research outputs found

    The Effects of Anthraquinone on Kraft Pulping

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    Popel chips were cooked in Kraft liquor modified by anthraquinone (AQ). Ten trials with varying levels of AQ, white liquor and cooking time were completed. It was found that the percent yield decreased by as much as 10 points as the level of AQ was increased. But the Kappa number decreased by only 2 points at the maximum AQ level; therefore, at a consistant Kappa number, the percent yield for the unmodified Kraft pulp would be greater than the modified pulp. Overall pulp strength increased significantly with the addition of 0.05% AQ, as was evidenced by the improvement of strength for the zero revolution refined sample

    Identifying Social Transformations and Crisis during the Pre-Monastic to Post-Viking era on Iona : New Insights from a Palynological and Palaeoentomological Perspective

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    Acknowledgements: Special acknowledgements go to Audrey Innes for her laboratory support, to Historic Environment Scotland and to the Leverhulme Trust who have helped fund this project and to the University of Glasgow who have helped support this work.Peer reviewedPostprin

    The Phase Space and Stellar Populations of Cluster Galaxies at z ~ 1: Simultaneous Constraints on the Location and Timescale of Satellite Quenching

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    We investigate the velocity vs. position phase space of z ~ 1 cluster galaxies using a set of 424 spectroscopic redshifts in 9 clusters drawn from the GCLASS survey. Dividing the galaxy population into three categories: quiescent, star-forming, and poststarburst, we find that these populations have distinct distributions in phase space. Most striking are the poststarburst galaxies, which are commonly found at small clustercentric radii with high clustercentric velocities, and appear to trace a coherent ``ring" in phase space. Using several zoom simulations of clusters we show that the coherent distribution of the poststarbursts can be reasonably well-reproduced using a simple quenching scenario. Specifically, the phase space is best reproduced if satellite quenching occurs on a rapid timescale (0.1 < tau_{Q} < 0.5 Gyr) after galaxies make their first passage of R ~ 0.5R_{200}, a process that takes a total time of ~ 1 Gyr after first infall. We compare this quenching timescale to the timescale implied by the stellar populations of the poststarburst galaxies and find that the poststarburst spectra are well-fit by a rapid quenching (tau_{Q} = 0.4^{+0.3}_{-0.4} Gyr) of a typical star-forming galaxy. The similarity between the quenching timescales derived from these independent indicators is a strong consistency check of the quenching model. Given that the model implies satellite quenching is rapid, and occurs well within R_{200}, this would suggest that ram-pressure stripping of either the hot or cold gas component of galaxies are the most plausible candidates for the physical mechanism. The high cold gas consumption rates at z ~ 1 make it difficult to determine if hot or cold gas stripping is dominant; however, measurements of the redshift evolution of the satellite quenching timescale and location may be capable of distinguishing between the two.Comment: 10 pages, 4 figures, submitted to the Ap

    Differential Burden of Musculoskeletal Pain in Blacks and Whites at the Time of Total Joint Replacement Surgery

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    Introduction: The existence of racial disparities in total knee (TKR) and hip (THR) replacement outcomes is well established. The role of musculoskeletal co-morbidities among black and white TKR patients at the time of surgery were investigated in a prospective cohort enrolled in the FORCE-TJR consortium of 131 surgeons in 22 US states. Materials & methods: Descriptive analyses were performed on 3,306 TKR and 2,439 THR patients. Data included sociodemographic factors (age, sex, race), BMI, comorbid conditions using the modified Charlson comorbidity scores, burden of musculoskeletal disease using the Knee/Hip injury and Osteoarthritis Outcome Score (KOOS/HOOS) in both knees and hips, emotional health based on the Short Form 36 (SF-36) Mental Component Score (MCS) and physical function based on the Physical Component Score (SF-36 PCS). Factors associated with pre-operative surgical joint pain and function were examined using multivariate stepwise linear regression models. Results: Compared to Whites, Blacks (143 hips and 201 knees) reported worse surgical joint pain (mean pain: 39.3 vs. 49.2 (hip); 43.4 vs. 53.2 (knee)), poorer surgical joint function (mean function: 38.9 vs. 45.7 (hip); 45.9 vs. 53.4 (knee)), poorer global function (mean PCS: 30.0 vs. 31.6 (hip); 31.3 vs. 33.1 (knee)), and more non-operative joints pain. (All p\u3c0.03). In adjusted multivariable models, differences at the time of surgery in surgical joint symptoms and global function were explained by differences in musculoskeletal pain in the hips, knees, and low back. Conclusion: Greater burden of musculoskeletal pain explains differences in pre-operative pain and function between Blacks and Whites and likely impacts rehabilitation and subsequent TJR outcomes

    Ground-truthing daily and lunar patterns of coral reef fish call rates on a US Virgin Island reef

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ferguson, S., Jensen, F., Hyer, M., Noble, A., Apprill, A., & Mooney, T. Ground-truthing daily and lunar patterns of coral reef fish call rates on a US Virgin Island reef. Aquatic Biology, 31, (2022): 77–87, https://doi.org/10.3354/ab00755.Coral reefs comprise some of the most biodiverse habitats on the planet. These ecosystems face a range of stressors, making quantifying community assemblages and potential changes vital to effective management. To understand short- and long-term changes in biodiversity and detect early warning signals of decline, new methods for quantifying biodiversity at scale are necessary. Acoustic monitoring techniques have proven useful in observing species activities and biodiversity on coral reefs through aggregate approaches (i.e. energy as a proxy). However, few studies have ground-truthed these acoustic analyses with human-based observations. In this study, we sought to expand these passive acoustic methods by investigating biological sounds and fish call rates on a healthy reef, providing a unique set of human-confirmed, labeled acoustic observations. We analyzed acoustic data from Tektite Reef, St. John, US Virgin Islands, over a 2 mo period. A subset of acoustic files was manually inspected to identify recurring biotic sounds and quantify reef activity throughout the day. We found a high variety of acoustic signals in this soundscape. General patterns of call rates across time conformed to expectations, with dusk and dawn showing important and significantly elevated peaks in soniferous fish activity. The data reflected high variability in call rates across days and lunar phases. Call rates did not correspond to sound pressure levels, suggesting that certain call types may drive crepuscular trends in sound levels while lower-level critical calls, likely key for estimating biodiversity and behavior, may be missed by gross sound level analyses.This research was funded by the National Science Foundation Biological Oceanography award 1536782. The experiments were conducted under National Park Service Scientific Research and Collecting Permits VIIS-2016-SCI-0017-20, and we thank the Park staff for their support

    Differential burden of musculoskeletal pain in African Americans and whites patients at the time of total joint replacement surgery

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    Objective: African Americans patients have greater operative joint pain and functional limitation at the time of total joint replacement (TJR) compared to white patients. We examined the factors associated with this apparent disparity. Methods: A consecutive sample of 5745 patients with advanced knee and hip osteoarthritis [who elected to undergo TJR in 2011-201] reported, preoperatively, medical comorbidities, operative and non-operative hip/ knee pain using Hip and Knee Disability and Osteoarthritis Outcome Scores (HOOS/KOOS), function using Short Form 36 Physical Component Score (PCS). Total burden of musculoskeletal pain was quantified as moderate/severe pain in non-operative hip and knee joints and lumbar back pain using Oswestry Disability Index (ODI). Associations among race, medical co-morbidites (modified Charlson), total musculoskeletal pain burden, operative joint pain, and functional limitations were examined using multivariable regression models. Results:Compared to Whites, African Americans (143 hips and 201 knees) reported worse surgical joint pain (mean pain: 39.3 vs. 49.2 [hip]; 43.4 vs. 53.2 [knee]), poorer surgical joint function (mean function: 38.9 vs. 45.7 [hip]; 45.9 vs. 53.4 [knee]), poorer global function (mean PCS: 30.0 vs. 31.6 [hip]; 31.3 vs. 33.1 [knee]), and more non-operative joints pain (p Conclusions: Greater burden of musculoskeletal pain explains differences in pre-operative pain and function between African American and white patients and likely impacts rehabilitation and subsequent TJR outcomes

    Greater Co-morbidity Burden is Associated with Greater Pain and Disability at Time of Total Knee Replacement Among African American Patients

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    Introduction: The existence of racial disparities in total joint replacement (TJR) care is well established based on Medicare and VA data.1,3 As compared to white patients, African American TJR patients have lower utilization rates, more pain, poorer function at the time of surgery, and higher post-operative complication rates.2,3 We analyzed a national prospective total knee replacement (TKR) cohort to further investigate patterns of medical and musculoskeletal co-morbidities among African American and white TKR patients. Methods: Descriptive analyses were performed on a national database (FORCE-TJR) of 3,313 TKR patients from 107 orthopedic surgeons. Data collected include patient sociodemographics (age, gender, race, education, insurance, household income, smoking status), modified Charlson co-morbidity scores, and pre-operative and post-operative pain and function scores (SF-36 PCS and MCS, WOMAC, KOOS/HOOS ADL score). To assess the total musculoskeletal pain burden, WOMAC pain scores were recorded for non-operative weight bearing joints as well as Oswestry low back pain scores. Multivariate models are in progress. Results: Preliminary descriptive analyses demonstrate a higher medical co-morbidity burden in African American TKR patients as compared to whites (COPD, DM, smoking), as well as worse baseline pain (mean WOMAC pain score = 43.46 vs. 52.92, p Conclusion: Preliminary results demonstrate significant differences in medical and musculoskeletal co-morbidities that correlate with poorer pain and function scores in African American patients at the time of TKR

    Profiling the mouse brain endothelial transcriptome in health and disease models reveals a core blood-brain barrier dysfunction module.

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    Blood vessels in the CNS form a specialized and critical structure, the blood-brain barrier (BBB). We present a resource to understand the molecular mechanisms that regulate BBB function in health and dysfunction during disease. Using endothelial cell enrichment and RNA sequencing, we analyzed the gene expression of endothelial cells in mice, comparing brain endothelial cells with peripheral endothelial cells. We also assessed the regulation of CNS endothelial gene expression in models of stroke, multiple sclerosis, traumatic brain injury and seizure, each having profound BBB disruption. We found that although each is caused by a distinct trigger, they exhibit strikingly similar endothelial gene expression changes during BBB disruption, comprising a core BBB dysfunction module that shifts the CNS endothelial cells into a peripheral endothelial cell-like state. The identification of a common pathway for BBB dysfunction suggests that targeting therapeutic agents to limit it may be effective across multiple neurological disorders
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