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  • 1
    In: Emerging Topics in Life Sciences, Portland Press Ltd., Vol. 2, No. 2 ( 2018-09-28), p. 149-159
    Abstract: The oxygenation of the atmosphere — one of the most fundamental transformations in Earth's history — dramatically altered the chemical composition of the oceans and provides a compelling example of how life can reshape planetary surface environments. Furthermore, it is commonly proposed that surface oxygen levels played a key role in controlling the timing and tempo of the origin and early diversification of animals. Although oxygen levels were likely more dynamic than previously imagined, we make a case here that emerging records provide evidence for low atmospheric oxygen levels for the majority of Earth's history. Specifically, we review records and present a conceptual framework that suggest that background oxygen levels were below 1% of the present atmospheric level during the billon years leading up to the diversification of early animals. Evidence for low background oxygen levels through much of the Proterozoic bolsters the case that environmental conditions were a critical factor in controlling the structure of ecosystems through Earth's history.
    Type of Medium: Online Resource
    ISSN: 2397-8554 , 2397-8562
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2018
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  • 2
    Online Resource
    Online Resource
    Portland Press Ltd. ; 2018
    In:  Emerging Topics in Life Sciences Vol. 2, No. 2 ( 2018-09-28), p. 235-245
    In: Emerging Topics in Life Sciences, Portland Press Ltd., Vol. 2, No. 2 ( 2018-09-28), p. 235-245
    Abstract: It is often assumed that rising environmental oxygen concentrations played a significant role in the timing of the first appearance of animals and the trajectory of their early proliferation and diversification. The inherent large size and complexity of animals come with large energy requirements — levels of energy that can best, if not only, be acquired through aerobic respiration. There is also abundant geochemical evidence for an increase in ocean–atmosphere O2 concentrations in temporal proximity with the emergence of the group. To adequately test this hypothesis, however, a thorough understanding of the history of environmental oxygenation in the time between the first appearance of eukaryotes and the eventual appearance of animals is necessary. In this review, we summarize the evidence for the prevailing long-term conditions of the Proterozoic Eon prior to the emergence of Metazoa and go on to highlight multiple independent geochemical proxy records that suggest at least two transient oxygenation events — at ca. 1.4 and ca. 1.1 billion years ago (Ga) — during this time. These emerging datasets open the door to an important possibility: while prevailing conditions during much of this time would likely have presented challenges for early animals, there were intervals when oxygenated conditions were more widespread and could have favored yet undetermined advances in eukaryotic innovation, including critical early steps toward animal evolution.
    Type of Medium: Online Resource
    ISSN: 2397-8554 , 2397-8562
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2018
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  • 3
    Online Resource
    Online Resource
    Portland Press Ltd. ; 2018
    In:  Emerging Topics in Life Sciences Vol. 2, No. 2 ( 2018-09-28), p. 223-233
    In: Emerging Topics in Life Sciences, Portland Press Ltd., Vol. 2, No. 2 ( 2018-09-28), p. 223-233
    Abstract: Animal life on Earth is generally accepted to have risen during a period of increasingly well-oxygenated conditions, but direct evidence for that relationship has previously eluded scientists. This gap reflects both the enigmatic nature of the early animal fossil record and the coarse temporal resolution of Precambrian environmental change. Here, we combine paleontological data from the Ediacara Biota, the earliest fossil animals, with geochemical evidence for fluctuating redox conditions. Using morphological and ecological novelties that broadly reflect oxygen demand, we show that the appearance of abundant oxygen-demanding organisms within the Ediacara Biota corresponds with a period of elevated global oxygen concentrations. This correlation suggests that a putative rise in oxygen levels may have provided the necessary environments for the diversification of complex body plans and energetically demanding ecologies. The potential loss of organisms with relatively high oxygen requirements in the latest Ediacaran coupled with an apparent return to low oxygen concentrations further supports the availability of oxygen as a control on early animal evolution. While the advent of animal life was probably the product of a variety of factors, the recognition of a possible connection between changing environmental conditions and the diversification of animal morphologies suggests that the availability of oxygen played a significant role in the evolution of animals on Earth.
    Type of Medium: Online Resource
    ISSN: 2397-8554 , 2397-8562
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2018
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  • 4
    Online Resource
    Online Resource
    Portland Press Ltd. ; 2018
    In:  Emerging Topics in Life Sciences Vol. 2, No. 2 ( 2018-09-28), p. 279-288
    In: Emerging Topics in Life Sciences, Portland Press Ltd., Vol. 2, No. 2 ( 2018-09-28), p. 279-288
    Abstract: It is generally agreed that early diversification of animals and significant rise of atmospheric and oceanic oxygen (O2) levels occurred in the Ediacaran (635–541 million years ago, Ma) and early Cambrian (ca. 541–509 Ma). The strength and nature of their relationship, however, remain unclear and debated. A recent wave of paleoredox research — with a particular focus on the fossiliferous sections in South China — demonstrates high spatial heterogeneity of oceanic O2 (redox) conditions and dynamic marine shelf oxygenation in a dominantly anoxic ocean during the Ediacaran and early Cambrian. This pattern shows a general spatiotemporal coupling to early animal evolution. We attribute dynamic shelf oxygenation to a complex interplay among the evolving atmosphere, continents, oceans, and biosphere during a critical period in Earth history. Our review supports the idea of a complex coevolution between increasing O2 levels and early diversification of animals, although additional work is required to fully delineate the timing and patterns of this coevolution and the mechanistic underpinnings.
    Type of Medium: Online Resource
    ISSN: 2397-8554 , 2397-8562
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2018
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  • 5
    Online Resource
    Online Resource
    Portland Press Ltd. ; 2018
    In:  Emerging Topics in Life Sciences Vol. 2, No. 2 ( 2018-09-28), p. 121-124
    In: Emerging Topics in Life Sciences, Portland Press Ltd., Vol. 2, No. 2 ( 2018-09-28), p. 121-124
    Abstract: The history of life on Earth progressed in parallel with the evolving oxygen state of the atmosphere and oceans, but the details of that relationship remain poorly known and debated. There is, however, general agreement that the first appreciable and persistent accumulation of oxygen in the oceans and atmosphere occurred around 2.3 to 2.4 billion years ago. Following this Great Oxidation Event, biospheric oxygen remained at relatively stable intermediate levels for more than a billion years. Much current research focuses on the transition from the intermediate conditions of this middle chapter in Earth history to the more oxygenated periods that followed — often emphasizing whether increasing and perhaps episodic oxygenation drove fundamental steps in the evolution of complex life and, if so, when. These relationships among early organisms and their environments are the thematic threads that stitch together the papers in this collection. Expert authors bring a mix of methods and opinions to their leading-edge reviews of the earliest proliferation and ecological impacts of eukaryotic life, the subsequent emergence and ecological divergence of animals, and the corresponding causes and consequences of environmental change.
    Type of Medium: Online Resource
    ISSN: 2397-8554 , 2397-8562
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2018
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  • 6
    In: Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science, Elsevier BV, Vol. 325, No. 7 ( 1997-10), p. 505-510
    Type of Medium: Online Resource
    ISSN: 1251-8050
    Language: French
    Publisher: Elsevier BV
    Publication Date: 1997
    SSG: 11
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  • 7
    In: BMC Health Services Research, Springer Science and Business Media LLC, Vol. 21, No. 1 ( 2021-12)
    Abstract: Predicting bed occupancy for hospitalised patients with COVID-19 requires understanding of length of stay (LoS) in particular bed types. LoS can vary depending on the patient’s “bed pathway” - the sequence of transfers of individual patients between bed types during a hospital stay. In this study, we characterise these pathways, and their impact on predicted hospital bed occupancy. Methods We obtained data from University College Hospital (UCH) and the ISARIC4C COVID-19 Clinical Information Network (CO-CIN) on hospitalised patients with COVID-19 who required care in general ward or critical care (CC) beds to determine possible bed pathways and LoS. We developed a discrete-time model to examine the implications of using either bed pathways or only average LoS by bed type to forecast bed occupancy. We compared model-predicted bed occupancy to publicly available bed occupancy data on COVID-19 in England between March and August 2020. Results In both the UCH and CO-CIN datasets, 82% of hospitalised patients with COVID-19 only received care in general ward beds. We identified four other bed pathways, present in both datasets: “Ward, CC, Ward”, “Ward, CC”, “CC” and “CC, Ward”. Mean LoS varied by bed type, pathway, and dataset, between 1.78 and 13.53 days. For UCH, we found that using bed pathways improved the accuracy of bed occupancy predictions, while only using an average LoS for each bed type underestimated true bed occupancy. However, using the CO-CIN LoS dataset we were not able to replicate past data on bed occupancy in England, suggesting regional LoS heterogeneities. Conclusions We identified five bed pathways, with substantial variation in LoS by bed type, pathway, and geography. This might be caused by local differences in patient characteristics, clinical care strategies, or resource availability, and suggests that national LoS averages may not be appropriate for local forecasts of bed occupancy for COVID-19. Trial registration The ISARIC WHO CCP-UK study ISRCTN66726260 was retrospectively registered on 21/04/2020 and designated an Urgent Public Health Research Study by NIHR.
    Type of Medium: Online Resource
    ISSN: 1472-6963
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
    detail.hit.zdb_id: 2050434-2
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  • 8
    In: BMC Nephrology, Springer Science and Business Media LLC, Vol. 23, No. 1 ( 2022-12)
    Abstract: Hospitalized patients with SARS-CoV2 develop acute kidney injury (AKI) frequently, yet gaps remain in understanding why adults seem to have higher rates compared to children. Our objectives were to evaluate the epidemiology of SARS-CoV2-related AKI across the age spectrum and determine if known risk factors such as illness severity contribute to its pattern. Methods Secondary analysis of ongoing prospective international cohort registry. AKI was defined by KDIGO-creatinine only criteria. Log-linear, logistic and generalized estimating equations assessed odds ratios (OR), risk differences (RD), and 95% confidence intervals (CIs) for AKI and mortality adjusting for sex, pre-existing comorbidities, race/ethnicity, illness severity, and clustering within centers. Sensitivity analyses assessed different baseline creatinine estimators. Results Overall, among 6874 hospitalized patients, 39.6% ( n  = 2719) developed AKI. There was a bimodal distribution of AKI by age with peaks in older age (≥60 years) and middle childhood (5–15 years), which persisted despite controlling for illness severity, pre-existing comorbidities, or different baseline creatinine estimators. For example, the adjusted OR of developing AKI among hospitalized patients with SARS-CoV2 was 2.74 (95% CI 1.66–4.56) for 10–15-year-olds compared to 30–35-year-olds and similarly was 2.31 (95% CI 1.71–3.12) for 70–75-year-olds, while adjusted OR dropped to 1.39 (95% CI 0.97–2.00) for 40–45-year-olds compared to 30–35-year-olds. Conclusions SARS-CoV2-related AKI is common with a bimodal age distribution that is not fully explained by known risk factors or confounders. As the pandemic turns to disproportionately impacting younger individuals, this deserves further investigation as the presence of AKI and SARS-CoV2 infection increases hospital mortality risk.
    Type of Medium: Online Resource
    ISSN: 1471-2369
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2041348-8
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  • 9
    In: Nature, Springer Science and Business Media LLC, Vol. 618, No. 7967 ( 2023-06-29), p. 974-980
    Type of Medium: Online Resource
    ISSN: 0028-0836 , 1476-4687
    RVK:
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    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2023
    detail.hit.zdb_id: 120714-3
    detail.hit.zdb_id: 1413423-8
    SSG: 11
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  • 10
    In: JAMA Network Open, American Medical Association (AMA), Vol. 5, No. 11 ( 2022-11-16), p. e2242354-
    Abstract: Cancer screening deficits during the first year of the COVID-19 pandemic were found to persist into 2021. Cancer-related deaths over the next decade are projected to increase if these deficits are not addressed. Objective To assess whether participation in a nationwide quality improvement (QI) collaborative, Return-to-Screening, was associated with restoration of cancer screening. Design, Setting, and Participants Accredited cancer programs electively enrolled in this QI study. Project-specific targets were established on the basis of differences in mean monthly screening test volumes (MTVs) between representative prepandemic (September 2019 and January 2020) and pandemic (September 2020 and January 2021) periods to restore prepandemic volumes and achieve a minimum of 10% increase in MTV. Local QI teams implemented evidence-based screening interventions from June to November 2021 (intervention period), iteratively adjusting interventions according to their MTVs and target. Interrupted time series analyses was used to identify the intervention effect. Data analysis was performed from January to April 2022. Exposures Collaborative QI support included provision of a Return-to-Screening plan-do-study-act protocol, evidence-based screening interventions, QI education, programmatic coordination, and calculation of screening deficits and targets. Main Outcomes and Measures The primary outcome was the proportion of QI projects reaching target MTV and counterfactual differences in the aggregate number of screening tests across time periods. Results Of 859 cancer screening QI projects (452 for breast cancer, 134 for colorectal cancer, 244 for lung cancer, and 29 for cervical cancer) conducted by 786 accredited cancer programs, 676 projects (79%) reached their target MTV. There were no hospital characteristics associated with increased likelihood of reaching target MTV except for disease site (lung vs breast, odds ratio, 2.8; 95% CI, 1.7 to 4.7). During the preintervention period (April to May 2021), there was a decrease in the mean MTV (slope, −13.1 tests per month; 95% CI, −23.1 to −3.2 tests per month). Interventions were associated with a significant immediate (slope, 101.0 tests per month; 95% CI, 49.1 to 153.0 tests per month) and sustained (slope, 36.3 tests per month; 95% CI, 5.3 to 67.3 tests per month) increase in MTVs relative to the preintervention trends. Additional screening tests were performed during the intervention period compared with the prepandemic period (170 748 tests), the pandemic period (210 450 tests), and the preintervention period (722 427 tests). Conclusions and Relevance In this QI study, participation in a national Return-to-Screening collaborative with a multifaceted QI intervention was associated with improvements in cancer screening. Future collaborative QI endeavors leveraging accreditation infrastructure may help address other gaps in cancer care.
    Type of Medium: Online Resource
    ISSN: 2574-3805
    Language: English
    Publisher: American Medical Association (AMA)
    Publication Date: 2022
    detail.hit.zdb_id: 2931249-8
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