78 research outputs found

    Twelve thousand years of dust: The Holocene global dust cycle constrained by natural archives

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    Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP paleodust datasets in the last two decades provided a target for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust dataset that moves on from the positive experience of DIRTMAP and takes into account new scientific challenges, by providing a concise and accessible dataset of temporally resolved records of dust mass accumulation rates and particle grain-size distributions. We consider data from ice cores, marine sediments, loess/paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows investigation of the potential, uncertainties and confidence level of dust mass accumulation rates reconstructions, and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 43 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggest that minimum dust fluxes are likely observed during the Early to mid-Holocene period (6000ā€“8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize datasets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance and variability of the global dust cycle during the Holocene, with dust load ranging from 17.1 to 20.5 Tg between 2000 and 10 000 years ago, and a minimum in the Early to Mid-Holocene (6000ā€“8000 years ago)

    MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy

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    Published online July 28, 2020 in Wiley Online Library (wileyonlinelibrary.com)Mucositis is a significant toxicity of cancer therapy with numerous systemic sequelae. The goal of this systematic review was to update the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) Clinical Practice Guidelines for the management of mucositis. METHODS: The literature was reviewed systematically to identify interventions for mucositis. Studies were rated according to the presence of major and minor flaws according to previously published criteria. The body of evidence for each intervention and in each treatment setting was assigned a level of evidence based on previously published criteria. Guidelines were developed based on the level of evidence, with 3 possible guideline determinations: recommendation, suggestion, or no guideline possible. RESULTS: The guideline covers evidence from 1197 publications related to oral or gastrointestinal mucositis. Thirteen new guidelines were developed for or against the use of various interventions in specific treatment settings, and 11 previous guidelines were confirmed after aa review of new evidence. Thirteen previously established guidelines were carried over because there was no new evidence for these interventions. CONCLUSIONS: The updated MASCC/ISOO Clinical Practice Guidelines for mucositis provide professional health caregivers with a clinical setting-specific, evidence-based tool to help with the management of mucositis in patients who have cancer. Cancer 2020;126:4423-4431.Sharon Elad, Karis Kin Fong Cheng, ajesh V. Lalla, Noam Yarom, Catherine Hong, Richard M. Logan, Joanne Bowen, Rachel Gibson, Deborah P. Saunders, Yehuda Zadik, Anura Ariyawardana, Maria Elvira Correa, Vinisha Ranna, and Paolo Bossi, for the Mucositis Guidelines Leadership Group of the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) include: Praveen Arany, Abdul Rahman Al-Azri ... Emma H. Bateman ... Janet K. Coller, Noor Al-Dasooqi, and Hannah Wardill. Other contributors include (in alphabetic order): Suzanne Ameringer ... Dorothy Keefe ... Bronwen Mayo ... Andrea M. Stringer ... et al

    Sedimentation rate, bulk density, accumulation rate of terrigenous material and grain sizes of ODP Leg 167 sites

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    The terrigenous mineral fraction of sediments recovered by drilling during Ocean Drilling Program Leg 167 at Sites 1018 and 1020 is used to evaluate changes in the source and transport of fine-grained terrigenous sediment and its relation to regional climates and the paleoceanographic evolution of the California Current system during the late Pleistocene. Preliminary time scales developed by correlation of oxygen isotope stratigraphies with the global SPECMAP record show average linear sedimentation rates in excess of 100 m/m.y., which provide an opportunity for high-resolution studies of terrigenous flux, grain size, and mineralogy. The mass flux of terrigenous minerals at Site 1018 varies from 5 to 30 g/(cm**2 x k.y.) and displays a general trend toward increased flux during glacials. The terrigenous record at Site 1020 shows a similar pattern of increased glacial input, but overall accumulation rates are significantly lower. Spectral analysis demonstrates that most of this variability is concentrated in frequency bands related to orbital cycles of eccentricity, tilt, and precession. Detailed grain-size analysis performed on the isolated terrigenous mineral fraction shows that sediments from Site 1018 are associated with higher energy transport and depositional regimes than those found at Site 1020. Grain-size data are remarkably uniform throughout the last 500 k.y., with no discernible difference observed between glacial and interglacial size distributions within each site. X-ray diffraction analysis of the <2-Āµm clay component suggests that the deposition of minerals found at Site 1020 is consistent with transport from a southern source during intervals of increased terrigenous input

    A systematic review of viral infections associated with oral involvement in cancer patients: a spotlight on Herpesviridea

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    Purpose: Our aim was to evaluate the literature for the prevalence of and interventions for oral viral infections and, based on scientific evidence, point to effective treatment protocols. Quality of life (QOL) and economic impact were assessed if available in the articles reviewed. Methods: Our search of the English literature focused on oral viral infections in cancer patients within the timeframe of 1989ā€“2007. Review methods were standardized. Cohort studies were used to determine the weighted prevalence of oral viral infection in cancer patients. The quality of selected articles were assessed and scored with respect to sources of bias, representativeness, scale validity, and sample size. Interventional studies were utilized to determine management guidelines. Literature search included measures of QOL and economic variables. Results: Prevalence of oral herpes simplex virus (HSV) infection in neutropenic patients was higher than in patients treated with radiotherapy for head and neck cancer (49.8% vs. 0%, respectively). In patients treated with radiochemotherapy for head and neck cancer, the prevalence of oral HSV infection increases up to 43.2% (CI, 0ā€“100%). Prevalence of HSV infection was higher when oral ulcers existed. Information about other oral viral infections is sparse. There was a significant benefit of using acyclovir to prevent HSV oral infection (at 800 mg/day). Various dosing protocols of valacyclovir achieved prevention of HSV reactivation (500 or 1,000 mg/day). The prevalence of HSV reactivation was similar for acyclovir and valacyclovir. No information about impact on QOL and economic burden was available. Conclusions: Acyclovir and valacyclovir are equally effective in preventing oral HSV infection. Neutropenic patients, who were primarily treated for hematological malignancies in the studies reviewed, are at a greater risk for viral infection.Sharon Elad, Yehuda Zadik, Ian Hewson, Allan Hovan, M. Elvira P. Correa, Richard Logan, Linda S. Elting, Fred K. L. Spijkervet, Michael T. Brennan and Viral Infections Section, Oral Care Study Group, Multinational Association of Supportive Care in Cancer (MASCC)/International Society of Oral Oncology (ISOO

    The Pacific Equatorial Age Transect, IODP Expeditions 320 and 321: Building a 50-Million-Year-Long Environmental Record of the Equatorial Pacific

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    In March 2009, the R/V JOIDES Resolution returned to operations after its extended refit and began with a drilling program ideally suited to its drilling strengths, the Pacific Equatorial Age Transect (PEAT, IODP Exp 320/321; Fig. 1A). The PEAT drilling program was developed to understand how a major oceanic region evolved over the Cenozoic Era(65ā€“0 Ma) and how it interacted with global climate. It specifically targeted the interval between 52 Ma and 0 Ma and drilled a series of sites that originated on the paleoequator. These sites have since been moved to the northwest by plate tectonics.The equatorial Pacific is an important target for paleocean ographic study because it is a significant ā€˜cogā€™ in the Earthā€™s climate machine, representing roughly half of the total tropical oceans that in turn represent roughly half of the total global ocean area. Prior drilling in both the Deep Sea Drilling Project (DSDP) and the Ocean Drilling Program (ODP) outlined the changes that have occurred through the Cenozoic (e.g., van Andel et al., 1975; Pisias et al., 1995). Not only did the earlier work fail to cover sufficient timeintervals but also many of the sites were cored with ā€˜first-generationā€™ scientific drilling technology with incomplete and disturbed sediment recovery and thus cannot be used for detailed studies

    Twelve thousand years of dust: the Holocene global dust cycle constrained by natural archives

    No full text
    Mineral dust plays an important role in the climate system by interacting with radiation, clouds, and biogeochemical cycles. In addition, natural archives show that the dust cycle experienced variability in the past in response to global and local climate change. The compilation of the DIRTMAP (Dust Indicators and Records from Terrestrial and MArine Palaeoenvironments) paleodust data sets in the last 2 decades provided a benchmark for paleoclimate models that include the dust cycle, following a time slice approach. We propose an innovative framework to organize a paleodust data set that builds on the positive experience of DIRTMAP and takes into account new scientific challenges by providing a concise and accessible data set of temporally resolved records of dust mass accumulation rates and particle grain size distributions. We consider data from ice cores, marine sediments, loessā€“paleosol sequences, lake sediments, and peat bogs for this compilation, with a temporal focus on the Holocene period. This global compilation allows the investigation of the potential, uncertainties, and confidence level of dust mass accumulation rate reconstructions and highlights the importance of dust particle size information for accurate and quantitative reconstructions of the dust cycle. After applying criteria that help to establish that the data considered represent changes in dust deposition, 45 paleodust records have been identified, with the highest density of dust deposition data occurring in the North Atlantic region. Although the temporal evolution of dust in the North Atlantic appears consistent across several cores and suggests that minimum dust fluxes are likely observed during the early to mid-Holocene period (6000ā€“8000 years ago), the magnitude of dust fluxes in these observations is not fully consistent, suggesting that more work needs to be done to synthesize data sets for the Holocene. Based on the data compilation, we used the Community Earth System Model to estimate the mass balance of and variability in the global dust cycle during the Holocene, with dust loads ranging from 17.2 to 20.8 Tg between 2000 and 10 000 years ago and with a minimum in the early to mid-Holocene (6000ā€“8000 years ago)
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