Publications by authors named "Kristin Bergmann"

Reconstructing the oxygenation history of Earth's oceans during the Ediacaran period (635 to 539 million years ago) has been challenging, and this has led to a polarizing debate about the environmental conditions that played host to the rise of animals. One focal point of this debate is the largest negative inorganic C-isotope excursion recognized in the geologic record, the Shuram excursion, and whether this relic tracks the global-scale oxygenation of Earth's deep oceans. To help inform this debate, we conducted a detailed geochemical investigation of two siliciclastic-dominated successions from Oman deposited through the Shuram Formation.

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The morphology and composition of clasts have the potential to reveal the nature and extent of erosional processes acting in a region. Dense accumulations of granule- to pebble-sized clasts covering the ground throughout the Glen Torridon region of Gale crater on Mars were studied using data acquired by the Mars Science Laboratory Curiosity rover between sols 2300 and 2593. In this study, measurements of shape, size, texture, and elemental abundance of unconsolidated granules and pebbles within northern Glen Torridon were compiled.

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Calcium carbonate (CaCO) biomineralizing organisms have played major roles in the history of life and the global carbon cycle during the past 541 Ma. Both marine diversification and mass extinctions reflect physiological responses to environmental changes through time. An integrated understanding of carbonate biomineralization is necessary to illuminate this evolutionary record and to understand how modern organisms will respond to 21st century global change.

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Determining how soft tissues are preserved and persist through geologic time are continuing challenge because decay begins immediately after senescence while diagenetic transformations generally progress over days to millions of years. However, in recent years, carbonate concretions containing partially-to-fully decayed macroorganisms have proven to be remarkable windows into the diagenetic continuum revealing insights into the fossilization process. This is because most concretions are the result of biologically induced mineral precipitation caused by the localized decay of organic matter, which oftentimes preserves a greater biological signal relative to their host sediment.

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Incontinentia pigmenti is an uncommon X-linked dominant neurocutaneous ectodermal dysplasia. The disorder is usually lethal in males in utero, although it may occasionally occur in males with somatic mosaicsism or Klinefelter syndrome. This is a case report of a rare case of incontinentia pigmenti in a newborn male who presented with characteristic skin eruptions following Blaschko's lines.

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The spatial coverage and temporal resolution of the Early Paleozoic paleoclimate record are limited, primarily due to the paucity of well-preserved skeletal material commonly used for oxygen-isotope paleothermometry. Bulk-rock [Formula: see text] datasets can provide broader coverage and higher resolution, but are prone to burial alteration. We assess the diagenetic character of two thick Cambro-Ordovician carbonate platforms with minimal to moderate burial by pairing clumped and bulk isotope analyses of micritic carbonates.

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Mudstone-hosted microfossils are a major component of the Proterozoic fossil record, particularly dominating the record of early eukaryotic life. Early organisms possessed no biomineralized parts to resist decay and controls on their fossilization in mudstones are poorly understood. Consequently, the Proterozoic fossil record is compromised-we do not know whether changing temporal/spatial patterns of microfossil occurrences reflect evolution or the distribution of favourable fossilization conditions.

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The rise of animals occurred during an interval of Earth history that witnessed dynamic marine redox conditions, potentially rapid plate motions, and uniquely large perturbations to global biogeochemical cycles. The largest of these perturbations, the Shuram carbon isotope excursion, has been invoked as a driving mechanism for Ediacaran environmental change, possibly linked with evolutionary innovation or extinction. However, there are a number of controversies surrounding the Shuram, including its timing, duration, and role in the concomitant biological and biogeochemical upheavals.

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Iron deficiency is a common cause of reactive thrombocytosis resulting in usually mild to moderately increased but sometimes even in extreme thrombocytosis (ie, >1000×10/L). We report a case of a 34-year-old woman who developed an increased platelet count of 1953×10/L. Upon admission, cytoreductive therapy was initiated until an underlying chronic myeloproliferative neoplasia was ruled out.

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About a decade after its introduction, the field of carbonate clumped isotope thermometry is rapidly expanding because of the large number of possible applications and its potential to solve long-standing questions in Earth Sciences. Major factors limiting the application of this method are the very high analytical precision required for meaningful interpretations, the relatively complex sample preparation procedures, and the mass spectrometric corrections needed. In this paper we first briefly review the evolution of the analytical and standardization procedures and discuss the major remaining sources of uncertainty.

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Febrile neutropenia (FN) is a common complication in patients with cancer during treatment with antineoplastic drugs. The initial cause is usually bacterial, and treatment of FN follows well-defined algorithms. We report a case of a 62-year-old patient with chronic lymphocytic leukaemia (CLL), who developed FN, which was unresponsive to both empirical antibacterial and empirical antifungal therapy.

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Microfossils, stromatolites, preserved lipids and biologically informative isotopic ratios provide a substantial record of bacterial diversity and biogeochemical cycles in Proterozoic (2500-541 Ma) oceans that can be interpreted, at least broadly, in terms of present-day organisms and metabolic processes. Archean (more than 2500 Ma) sedimentary rocks add at least a billion years to the recorded history of life, with sedimentological and biogeochemical evidence for life at 3500 Ma, and possibly earlier; phylogenetic and functional details, however, are limited. Geochemistry provides a major constraint on early evolution, indicating that the first bacteria were shaped by anoxic environments, with distinct patterns of major and micronutrient availability.

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The purpose of the study was to assess the risk of first-time bloodstream infection (BSI) according to type of central venous catheter (CVC) during induction therapy in children with acute lymphoblastic leukemia (ALL). Patients eligible for our analysis were all newly diagnosed children with ALL treated at 3 pediatric centers in Denmark between 2008 and 2014. A total of 136 patients were followed from initial CVC placement until first BSI, CVC removal, death, or day 28, whichever occurred first.

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Article Synopsis
  • Understanding ancient climate changes is challenging because it's tough to separate ocean temperature trends from changes in ice volume.
  • Researchers used a method called carbonate "clumped" isotope paleothermometry to determine ocean temperatures and estimate ice volumes during the Late Ordovician-Early Silurian glaciation.
  • They discovered that tropical ocean temperatures ranged from 32° to 37°C, with a brief cooling period of about 5°C, and noted that this cooling occurred during a time when ice volumes may have been as large as those from the last Pleistocene glacial maximum, linking it to significant shifts in the carbon cycle and the Late Ordovician mass extinction.
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