Peatland pools are tightly coupled to the contemporary carbon cycle.

Peatlands are globally important stores of soil carbon (C) formed over millennial timescales but are at risk of destabilization by human and climate disturbance. Pools are ubiquitous features of many peatlands and can contain very high concentrations of C mobilized in dissolved and particulate organic form and as the greenhouses gases carbon dioxide (CO ) and methane (CH ). The radiocarbon content ( C) of these aquatic C forms tells us whether pool C is generated by contemporary primary production or from destabilized C released from deep peat layers where it was previously stored for millennia.

Methanotrophic potential of Dutch canal wall biofilms is driven by Methylomonadaceae.

Global urbanization of waterways over the past millennium has influenced microbial communities in these aquatic ecosystems. Increased nutrient inputs have turned most urban waters into net sources of the greenhouse gases carbon dioxide (CO2) and methane (CH4). Here, canal walls of five Dutch cities were studied for their biofilm CH4 oxidation potential, alongside field observations of water chemistry, and CO2 and CH4 emissions.

Comparing end-tidal CO, respiration volume per time (RVT), and average gray matter signal for mapping cerebrovascular reactivity amplitude and delay with breath-hold task BOLD fMRI.

Cerebrovascular reactivity (CVR), defined as the cerebral blood flow response to a vasoactive stimulus, is an imaging biomarker with demonstrated utility in a range of diseases and in typical development and aging processes. A robust and widely implemented method to map CVR involves using a breath-hold task during a BOLD fMRI scan. Recording end-tidal CO (PCO) changes during the breath-hold task is recommended to be used as a reference signal for modeling CVR amplitude in standard units (%BOLD/mmHg) and CVR delay in seconds.

Automatic Segmentation of Kidneys and Kidney Tumors: The KiTS19 International Challenge.

Clinicians rely on imaging features to calculate complexity of renal masses based on validated scoring systems. These scoring methods are labor-intensive and are subjected to interobserver variability. Artificial intelligence has been increasingly utilized by the medical community to solve such issues.

Amsterdam urban canals contain novel niches for methane-cycling microorganisms.

Urbanised environments have been identified as hotspots of anthropogenic methane emissions. Especially urban aquatic ecosystems are increasingly recognised as important sources of methane. However, the microbiology behind these emissions remains unexplored.

Potential Impact of Pass/Fail Scores on USMLE Step 1: Predictors of Excellence in Obstetrics and Gynecology Residency Training.

Aim: The study aims to determine resident applicant metrics most predictive of academic and clinical performance as measured by the Council of Resident Education in Obstetrics and Gynecology (CREOG) examination scores and Accreditation Council for Graduate Medical Education (ACGME) clinical performance (Milestones) in the aftermath of United States Medical Licensing Examination Scores (USMLE) Step 1 becoming a pass/fail examination.

Methods: In this retrospective study, electronic and paper documents for Wayne State University Obstetrics and Gynecology residents matriculated over a 5-year period ending July 2018 were collected. USMLE scores, clerkship grade, and wording on the letters of recommendation as well as Medical Student Performance Evaluation (MSPE) were extracted from the Electronic Residency Application Service (ERAS) and scored numerically.

Can ACGME Milestones predict surgical specialty board passage: an example in Obstetrics and Gynecology.

Background: Multiple tools including Accreditation Council for Graduate Medical Education (ACGME) standardized milestones can be utilized to assess trainee and residency program performance. However, little is known regarding the objective validation of these tools in predicting written board passage.

Methods: In this retrospective study, data was gathered on n = 45 Wayne State University Obstetrics and Gynecology program graduates over the five-year period ending July 2018.

Stream Dissolved Organic Matter in Permafrost Regions Shows Surprising Compositional Similarities but Negative Priming and Nutrient Effects.

Permafrost degradation is delivering bioavailable dissolved organic matter (DOM) and inorganic nutrients to surface water networks. While these permafrost subsidies represent a small portion of total fluvial DOM and nutrient fluxes, they could influence food webs and net ecosystem carbon balance via priming or nutrient effects that destabilize background DOM. We investigated how addition of biolabile carbon (acetate) and inorganic nutrients (nitrogen and phosphorus) affected DOM decomposition with 28-day incubations.

The state of the art in kidney and kidney tumor segmentation in contrast-enhanced CT imaging: Results of the KiTS19 challenge.

There is a large body of literature linking anatomic and geometric characteristics of kidney tumors to perioperative and oncologic outcomes. Semantic segmentation of these tumors and their host kidneys is a promising tool for quantitatively characterizing these lesions, but its adoption is limited due to the manual effort required to produce high-quality 3D segmentations of these structures. Recently, methods based on deep learning have shown excellent results in automatic 3D segmentation, but they require large datasets for training, and there remains little consensus on which methods perform best.

Publisher Correction: East Siberian Arctic inland waters emit mostly contemporary carbon.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

East Siberian Arctic inland waters emit mostly contemporary carbon.

Inland waters (rivers, lakes and ponds) are important conduits for the emission of terrestrial carbon in Arctic permafrost landscapes. These emissions are driven by turnover of contemporary terrestrial carbon and additional pre-aged (Holocene and late-Pleistocene) carbon released from thawing permafrost soils, but the magnitude of these source contributions to total inland water carbon fluxes remains unknown. Here we present unique simultaneous radiocarbon age measurements of inland water CO, CH and dissolved and particulate organic carbon in northeast Siberia during summer.

Norethindrone is superior to combined oral contraceptive pills in short-term delay of menses and onset of breakthrough bleeding: a randomized trial.

Background: To determine whether oral norethindrone acetate is superior to combined oral contraceptives (OCP) in delaying menstruation and preventing breakthrough bleeding when started late in the cycle.

Methods: This article comprises of a case control study followed by a pilot randomized controlled study. In the first study, four women who presented late in their cycle and desired avoiding vaginal bleeding within 10 days before a wedding were started on norethindrone 5 mg three times daily and compared to age matched controls started on OCPs.

Increases in temperature and nutrient availability positively affect methane-cycling microorganisms in Arctic thermokarst lake sediments.

Arctic permafrost soils store large amounts of organic matter that is sensitive to temperature increases and subsequent microbial degradation to methane (CH ) and carbon dioxide (CO ). Here, we studied methanogenic and methanotrophic activity and community composition in thermokarst lake sediments from Utqiag˙vik (formerly Barrow), Alaska. This experiment was carried out under in situ temperature conditions (4°C) and the IPCC 2013 Arctic climate change scenario (10°C) after addition of methanogenic and methanotrophic substrates for nearly a year.

Cognitive science in the field: A preschool intervention durably enhances intuitive but not formal mathematics.

Many poor children are underprepared for demanding primary school curricula. Research in cognitive science suggests that school achievement could be improved by preschool pedagogy in which numerate adults engage children's spontaneous, nonsymbolic mathematical concepts. To test this suggestion, we designed and evaluated a game-based preschool curriculum intended to exercise children's emerging skills in number and geometry.

Ancient dissolved methane in inland waters revealed by a new collection method at low field concentrations for radiocarbon (C) analysis.

Methane (CH) is a powerful greenhouse gas that plays a prominent role in the terrestrial carbon (C) cycle, and is released to the atmosphere from freshwater systems in numerous biomes globally. Radiocarbon (C) analysis can indicate both the age and source of CH in natural environments. In contrast to CH present in bubbles released from aquatic sediments (ebullition), dissolved CH in lakes and streams can be present in low concentrations compared to carbon dioxide (CO), and therefore obtaining sufficient aquatic CH for radiocarbon (C) analysis remains a major technical challenge.

Biogeochemistry of "pristine" freshwater stream and lake systems in the western Canadian Arctic.

Climate change poses a substantial threat to the stability of the Arctic terrestrial carbon (C) pool as warmer air temperatures thaw permafrost and deepen the seasonally-thawed active layer of soils and sediments. Enhanced water flow through this layer may accelerate the transport of C and major cations and anions to streams and lakes. These act as important conduits and reactors for dissolved C within the terrestrial C cycle.

Cocaine-related aortic dissection: lessons from the International Registry of Acute Aortic Dissection.

Background: Acute aortic dissection associated with cocaine use is rare and has been reported predominantly as single cases or in small patient cohorts.

Methods: Our study analyzed 3584 patients enrolled in the International Registry of Acute Aortic Dissection from 1996 to 2012. We divided the population on the basis of documented cocaine use (C+) versus non cocaine use (C-) and further stratified the cohorts into type A (33 C+/2332, 1.