1,061 research outputs found

    Simulating the mid-Pliocene Warm Period with the CCSM4 model

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    This paper describes the experimental design and model results from a 500 yr fully coupled Community Climate System, version 4, simulation of the mid-Pliocene Warm Period (mPWP) (ca. 3.3–3.0 Ma). We simulate the mPWP using the "alternate" protocol prescribed by the Pliocene Model Intercomparison Project (PlioMIP) for the AOGCM simulation (Experiment 2). Results from the CCSM4 mPWP simulation show a 1.9 °C increase in global mean annual temperature compared to the 1850 preindustrial control, with a polar amplification of ~3 times the global warming. Global precipitation increases slightly by 0.09 mm day−1 and the monsoon rainfall is enhanced, particularly in the Northern Hemisphere (NH). Areal sea ice extent decreases in both hemispheres but persists through the summers. The model simulates a relaxation of the zonal sea surface temperature (SST) gradient in the tropical Pacific, with the El Niño–Southern Oscillation (Niño3.4) ~20% weaker than the preindustrial and exhibiting extended periods of quiescence of up to 150 yr. The maximum Atlantic meridional overturning circulation and northward Atlantic oceanic heat transport are indistinguishable from the control. As compared to PRISM3, CCSM4 overestimates Southern Hemisphere (SH) sea surface temperatures, but underestimates NH warming, particularly in the North Atlantic, suggesting that an increase in northward ocean heat transport would bring CCSM4 SSTs into better alignment with proxy data

    The management of diabetic ketoacidosis in children

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    The object of this review is to provide the definitions, frequency, risk factors, pathophysiology, diagnostic considerations, and management recommendations for diabetic ketoacidosis (DKA) in children and adolescents, and to convey current knowledge of the causes of permanent disability or mortality from complications of DKA or its management, particularly the most common complication, cerebral edema (CE). DKA frequency at the time of diagnosis of pediatric diabetes is 10%–70%, varying with the availability of healthcare and the incidence of type 1 diabetes (T1D) in the community. Recurrent DKA rates are also dependent on medical services and socioeconomic circumstances. Management should be in centers with experience and where vital signs, neurologic status, and biochemistry can be monitored with sufficient frequency to prevent complications or, in the case of CE, to intervene rapidly with mannitol or hypertonic saline infusion. Fluid infusion should precede insulin administration (0.1 U/kg/h) by 1–2 hours; an initial bolus of 10–20 mL/kg 0.9% saline is followed by 0.45% saline calculated to supply maintenance and replace 5%–10% dehydration. Potassium (K) must be replaced early and sufficiently. Bicarbonate administration is contraindicated. The prevention of DKA at onset of diabetes requires an informed community and high index of suspicion; prevention of recurrent DKA, which is almost always due to insulin omission, necessitates a committed team effort

    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 (6000–8000 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 (6000–8000 years ago)

    Standardized Outcomes in Nephrology-Transplantation: A Global Initiative to Develop a Core Outcome Set for Trials in Kidney Transplantation.

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    BACKGROUND: Although advances in treatment have dramatically improved short-term graft survival and acute rejection in kidney transplant recipients, long-term graft outcomes have not substantially improved. Transplant recipients also have a considerably increased risk of cancer, cardiovascular disease, diabetes, and infection, which all contribute to appreciable morbidity and premature mortality. Many trials in kidney transplantation are short-term, frequently use unvalidated surrogate endpoints, outcomes of uncertain relevance to patients and clinicians, and do not consistently measure and report key outcomes like death, graft loss, graft function, and adverse effects of therapy. This diminishes the value of trials in supporting treatment decisions that require individual-level multiple tradeoffs between graft survival and the risk of side effects, adverse events, and mortality. The Standardized Outcomes in Nephrology-Transplantation initiative aims to develop a core outcome set for trials in kidney transplantation that is based on the shared priorities of all stakeholders. METHODS: This will include a systematic review to identify outcomes reported in randomized trials, a Delphi survey with an international multistakeholder panel (patients, caregivers, clinicians, researchers, policy makers, members from industry) to develop a consensus-based prioritized list of outcome domains and a consensus workshop to review and finalize the core outcome set for trials in kidney transplantation. CONCLUSIONS: Developing and implementing a core outcome set to be reported, at a minimum, in all kidney transplantation trials will improve the transparency, quality, and relevance of research; to enable kidney transplant recipients and their clinicians to make better-informed treatment decisions for improved patient outcomes

    Nicotinamide Phosphoribosyltransferase/Visfatin Does Not Catalyze Nicotinamide Mononucleotide Formation in Blood Plasma

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    Nicotinamide (Nam) phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in mammalian NAD synthesis, catalyzing nicotinamide mononucleotide (NMN) formation from Nam and 5-phosphoribosyl 1-pyrophosphate (PRPP). NAMPT has also been described as an adipocytokine visfatin with a variety of actions, although physiological significance of this protein remains unclear. It has been proposed that possible actions of visfatin are mediated through the extracellular formation of NMN. However, we did not detect NMN in mouse blood plasma, even with a highly specific and sensitive liquid chromatography/tandem mass spectrometry. Furthermore, there is no or little ATP, the activator of NAMPT, in extracellular spaces. We thus questioned whether visfatin catalyzes the in situ formation of NMN under such extracellular milieus. To address this question, we here determined Km values for the substrates Nam and PRPP in the NAMPT reaction without or with ATP using a recombinant human enzyme and found that 1 mM ATP dramatically decreases Km values for the substrates, in particular PRPP to its intracellular concentration. Consistent with the kinetic data, only when ATP is present at millimolar levels, NAMPT efficiently catalyzed the NMN formation at the intracellular concentrations of the substrates. Much lower concentrations of Nam and almost the absence of PRPP and ATP in the blood plasma suggest that NAMPT should not efficiently catalyze its reaction under the extracellular milieu. Indeed, NAMPT did not form NMN in the blood plasma. From these kinetic analyses of the enzyme and quantitative determination of its substrates, activator, and product, we conclude that visfatin does not participate in NMN formation under the extracellular milieus. Together with the absence of NMN in the blood plasma, our conclusion does not support the concept of “NAMPT-mediated systemic NAD biosynthesis.” Our study would advance current understanding of visfatin physiology

    Human-Centered Design Components in Spiral Model to Improve Mobility of Older Adults

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    As humans grow older, their cognitive needs change more frequently due to distal and proximal life events. Designers and developers need to come up with better designs that integrate older users’ needs in a short period of time with more interaction with the users. Therefore, the positioning of human end users in the center of the design itself is not the key to the success of design artifacts while designing applications for older adults to use a smartphone as a promising tool for journey planner while using public transportation. This study analyzed the use of human-centered design (HCD) components, the spiral model, and the design for failure (DfF) approach to improve the interactions between older users and designers/developers in gathering usability needs in the concept stage and during the development of the app with short iterative cycles. To illustrate the importance of the applied approach, a case study with particular focus on older adults is presented.The results presented in this study are based on “Assistant” project funded by AAL JP, co-funded by the European Union. The authors would like to thank Dr. Stefan Carmien, my colleague in Assistant, for mentoring and for reading and making comments in the earlier versions of this chapter; participating research institutes; funding agencies; and companies from Finland, Spain, Austria, France, and the United Kingdom for their active support throughout the project

    VEMAP Phase 2 Bioclimatic Database. I. Gridded Historical (20th century) Climate for Modeling Ecosystem Dynamics Across the Conterminous USA

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    Analysis and simulation of biospheric responses to historical forcing require surface climate data that capture those aspects of climate that control ecological processes, including key spatial gradients and modes of temporal variability. We developed a multivariate, gridded historical climate dataset for the conterminous USA as a common input database for the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), a biogeochemical and dynamic vegetation model intercomparison. The dataset covers the period 1895-1993 on a 0.5° latitude/longitude grid. Climate is represented at both monthly and daily timesteps. Variables are: precipitation, mininimum and maximum temperature, total incident solar radiation, daylight-period irradiance, vapor pressure, and daylight-period relative humidity. The dataset was derived from US Historical Climate Network (HCN), cooperative network, and snowpack telemetry (SNOTEL) monthly precipitation and mean minimum and maximum temperature station data. We employed techniques that rely on geostatistical and physical relationships to create the temporally and spatially complete dataset. We developed a local kriging prediction model to infill discontinuous and limited-length station records based on spatial autocorrelation structure of climate anomalies. A spatial interpolation model (PRISM) that accounts for physiographic controls was used to grid the infilled monthly station data. We implemented a stochastic weather generator (modified WGEN) to disaggregate the gridded monthly series to dailies. Radiation and humidity variables were estimated from the dailies using a physically-based empirical surface climate model (MTCLIM3). Derived datasets include a 100 yr model spin-up climate and a historical Palmer Drought Severity Index (PDSI) dataset. The VEMAP dataset exhibits statistically significant trends in temperature, precipitation, solar radiation, vapor pressure, and PDSI for US National Assessment regions. The historical climate and companion datasets are available online at data archive centers

    Evaluation of the nutrition knowledge of sports department students of universities

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    <p>Abstract</p> <p>Background</p> <p>Individuals who have knowledge on the importance of adequate and balanced diet and reflect this knowledge to their behaviors are considered to be more successful in sports life. The present study aims to evaluate the nutrition knowledge of students receiving sports education in universities.</p> <p>Methods</p> <p>The study sample consists of 343 voluntary students from the Sports Departments of Hacettepe, Gazi and Ankara Universities in Ankara. The questionnaire used in the study included a demographic section, and 30 questions on true-false nutrition knowledge. For the reliability of the questionnaire, the internal consistency coefficient was calculated and the Kuder Richardson (KR-20) value was found to be 0.71. For higher reliability, 9 dysfunctional questions were excluded from the questionnaire. The research data were collected through a questionnaire form and face-to-face interviews. For the statistical analyses of the data, tables were prepared to show mean, standard deviation (<inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1550-2783-8-11-i1"><m:mover accent="true"><m:mrow><m:mi>X</m:mi></m:mrow><m:mo class="MathClass-op">̄</m:mo></m:mover><m:mo class="MathClass-bin">±</m:mo><m:mi>S</m:mi><m:mi>D</m:mi></m:math></inline-formula>) and percentage (%) values. In order to determine the nutrition knowledge of students, the "independent t test" was used for nutrition lesson and gender.</p> <p>Results</p> <p>University students receiving sports education and expected to continue their professional lives on sport-related fields were determined to have the lack of knowledge on nutrition. The mean value about the nutrition knowledge of the first year students was found 11.150 ± 2.962, while the mean value of the fourth year students was 13.460 ± 3.703, and the difference is statistically significant (p = .000).</p> <p>Conclusion</p> <p>Students, coaches and teachers in physical education were found not to give the necessary importance to their diets, and they were still not aware of the importance of nutrition on performance.</p

    The impact of preoperative anxiety and education level on long-term mortality after cardiac surgery

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    <p>Abstract</p> <p>Background</p> <p>Psychosocial factors have shown independent predictive value in the development of cardiovascular diseases. Although there is strong evidence to support the role of psychosocial factors in cardiovascular mortality, there is a scarcity of knowledge about how these factors are related. Therefore, we investigated the relationship between depression, anxiety, education, social isolation and mortality 7.5 years after cardiac surgery.</p> <p>Methods</p> <p>After informed consent, 180 patients undergoing cardiac surgery between July 2000 and May 2001 were prospectively enrolled and followed for ten years. During the follow-up period, the patients were contacted annually by mail. Anxiety (Spielberger State-Trait Anxiety Inventory, STAI-S/STAI-T), depression (Beck Depression Inventory, BDI) and the number and reason for rehospitalizations were assessed each year. Those patients who did not respond were contacted by telephone, and national registries were searched for deaths.</p> <p>Results</p> <p>During a median follow-up of 7.6 years (25<sup>th</sup> to 75<sup>th</sup> percentile, 7.4 to 8.1 years), the mortality rate was 23.6% (95% confidence interval [CI] 17.3-29.9; 42 deaths). In a Cox regression model, the risk factors associated with an increased risk of mortality were a higher EUROSCORE (points; Adjusted Hazard Ratio (AHR):1.30, 95%CI:1.07-1.58)), a higher preoperative STAI-T score (points; AHR:1.06, 95%CI 1.02-1.09), lower education level (school years; AHR:0.86, 95%CI:0.74-0.98), and the occurrence of major adverse cardiac and cerebral events during follow up (AHR:7.24, 95%CI:2.65-19.7). In the postdischarge model, the same risk factors remained.</p> <p>Conclusions</p> <p>Our results suggest that the assessment of psychosocial factors, particularly anxiety and education may help identify patients at an increased risk for long-term mortality after cardiac surgery.</p
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