196,276 research outputs found
Supplementary Material: Surface Sediment Samples From Early Age of Seafloor Exploration Can Provide a Late 19th Century Baseline of the Marine Environment
No full textOcean-floor sediment samples collected up to 150 years ago represent an important historical archive to benchmark global changes in the seafloor environment, such as species' range shifts and pollution trends. Such benchmarking requires that the historical sediment samples represent the state of the environment at-or shortly before the time of collection. However, early oceanographic expeditions sampled the ocean floor using devices like the sounding tube or a dredge, which potentially disturb the sediment surface and recover a mix of Holocene (surface) and deeper, Pleistocene sediments. Here we use climate-sensitive microfossils as a fast biometric method to assess if historical seafloor samples contain a mixture of modern and glacial sediments. Our assessment is based on comparing the composition of planktonic foraminifera (PF) assemblages in historical samples with Holocene and Last Glacial Maximum (LGM) global reference datasets. We show that eight out of the nine historical samples contain PF assemblages more similar to the Holocene than to the LGM PF assemblages, but the comparisons are only significant when there is a high local species' temporal turnover (from the LGM to the Holocene). When analysing temporal turnover globally, we show that upwelling and temperate regions had greatest species turnover, which are areas where our methodology would be most diagnostic. Our results suggest that sediment samples from historical collections can provide a baseline of the state of marine ecosystems in the late nineteenth century, and thus be used to assess ocean global change trends. ## Related materials: Rillo MC, Kucera M, Ezard THG and Miller CG (2019) Surface Sediment Samples From Early Age of Seafloor Exploration Can Provide a Late 19th Century Baseline of the Marine Environment. Front. Mar. Sci. 5:517. doi: https://doi.org/10.3389/fmars.2018.00517 Marina Costa Rillo (2016). Dataset: Henry Buckley Collection of Planktonic Foraminifera. Natural History Museum Data Portal (data.nhm.ac.uk). https://doi.org/10.5519/0035055</span
Reliability of DXA for the measurement of total and regional body composition in elite soccer players
No full textReliability of DXA for the measurement of total and regional body composition in elite soccer players
Fanchini M, Guido Rillo, Mattias Bruni, Carwyn Sharp
AS Roma Football Club, Roma, ITA
University of Verona, Faculty of Exercise and Sport Science, ITA;
INTRODUCTION
Dual-energy X-ray absorptiometry (DXA) is widely used for the assessment of total and regional body composition. Acquisition of the data can be done automatically with the in-built software however the software may under/overestimate regional parameters (i.e. legs). As such, the data may also be acquired by operator manual adjustment of the regions-of-interest (ROI) but the experience of the operator may influence the accuracy and reliability. In elite football monitoring leg muscle mass is relevant therefore operator adjustment may be required. The aim of this study was to examine the reliability of total and regional body composition when comparing automatic and manual ROI assessment performed by operators with different experience levels.
METHODS
Twenty-four elite soccer players (age 18 ± 1 yrs; height 179 ± 5 cm; body mass 72 ± 5 kg) from an Italian Serie-A team participated in a test-retest study. Tests were performed with Lunar iDXA (GE Healthcare Lunar, Madison, USA) and examined with in-built software (enCORE 17, GE Medical Systems Ultrasound & Primary Care Diagnostics, USA) on two different days. Total body fat mass (FM) and free fat mass (FFM) were examined as total body composition, and free fat mass of right and left legs (FFMR and FFML) were examined as regional body composition parameters. ROI were determined automatically (AROI) and by two operators with low and high experience (Low1 and High1). After two weeks, the operators were asked to do the analysis again (Low2 and High2) on the same images. Reliability was examined as Typical Error of Measurement (expressed as percentage, TEM) and Intraclass Correlation Coefficient (ICC).
RESULTS
The values were within the range 9.7-10.2 kg for FM, 58.8-59.5 kg for FFM, 10.3-12.8 kg for FFMR and 10.2-12.7 kg for FFML. The TEMs were within the range 2.0-2.4% for FM and 0.8-0.9% for FFM for all the assessment. The TEMs for FFMR were 1.4, 4.1, 1.2, 1.6, 1.3 % for AROI, Low1, High1, Low2 and High2 respectively. The TEMs for FFML were 2.0, 3.9, 1.1, 1.3, 1.1 % for AROI, Low1, High1, Low2 and High2 respectively. Low1 showed higher values of TEM for FFMR and FFML.
The ICC were within the range 0.99-1.00 for FM, 0.82-0.98 for FFMR, 0.83-0.98 for FFML and 0.99 for FFM.
DISCUSSION
The reliability of total and regional body parameters found in the present group of elite soccer players was similar to the values reported in the literature (1, 2). No significant difference was found between reliability parameters in FM, FFM however the lowest reliability found in Low1 in FFMR and FFML suggested the low experience of the operator have influenced the DXA results in his first assessment. Even if operators are familiarized with ROI customization they need experience to provide reliable outcomes.
1. Hart NH, Nimphius S, Spiteri T, Cochrane JL, Newton RU. J Sports Sci Med, 2015, 14, 620-626
2. Bilsborough JC, Greenway K, Opar D, Livingstone S, Cordy J, Coutts AJ. J Sports Sci, 2014, 19, 1821-
Optical properties of high-pressure fluid hydrogen across molecular dissociation
No full textOptical properties of compressed fluid hydrogen in the region where dissociation and metallization is observed are computed by ab initio methods and compared with recent experimen- tal results. We confirm that at T>3,000 K, both processes are continuous, while at T<1,500 K, the first-order phase transi- tion is accompanied by a discontinuity of the dc conductivity and the thermal conductivity, while both the reflectivity and absorption coefficient vary rapidly but continuously. Our results support the recent analysis of National Ignition Facility (NIF) experiments [Celliers PM, et al. (2018) Science 361:677–682], which assigned the inception of metallization to pressures where the reflectivity is ⇠0.3. Our results also support the conclusion that the temperature plateau seen in laser-heated diamond-anvil cell (DAC) experiments at temperatures higher than 1,500 K corre- sponds to the onset of optical absorption, not to the phase transition. hydroge
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Studio comparativo tra diversi sistemi di stimolazione rate-responsive.
No full textDa "L'elettrostimolazione cardiaca tra clinica e tecnologia".Edizioni Luigi Pozzi
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Studio comparativo tra diversi sistemi di stimolazione rate-responsive.
No full textDa "L'elettrostimolazione cardiaca tra clinica e tecnologia".Edizioni Luigi Pozzi
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
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