1,307 research outputs found
Frequency and type of adverse analytical findings in athletics: Differences among disciplines.
Athletics is a highly diverse sport that contains a set of disciplines grouped into jumps,
throws, races of varying distances, and combined events. From a physiological standpoint,
the physical capabilities linked to success are quite different among
disciplines, with varying involvements of muscle strength, muscle power, and
endurance. Thus, the use of banned substances in athletics might be dictated by physical
dimensions of each discipline. Thus, the aim of this investigation was to
analyse the number and distribution of adverse analytical findings per drug class in
athletic disciplines. The data included in this investigation were gathered from the
Anti-Doping Testing Figure Report made available by the World Anti-Doping Agency
(from 2016 to 2018). Interestingly, there were no differences in the frequency of
adverse findings (overall, 0.95%, range from 0.77 to 1.70%) among disciplines
despite long distance runners having the highest number of samples analysed per year
( 9812 samples/year). Sprinters and throwers presented abnormally high
proportions of adverse analytical findings within the group of anabolic agents
(p < 0.01); middle- and long-distance runners presented atypically high proportions of
findings related to peptide hormones and growth factors (p < 0.01); racewalkers presented
atypically high proportions of banned diuretics and masking agents (p = 0.05).
These results suggest that the proportion of athletes that are using banned substances
is similar among the different disciplines of athletics. However, there are substantial
differences in the class of drugs more commonly used in each discipline. This information
can be used to effectively enhance anti-doping testing protocols in athletics.post-print1.911 K
Evolutionary and pulsational properties of white dwarf stars
Abridged. White dwarf stars are the final evolutionary stage of the vast
majority of stars, including our Sun. The study of white dwarfs has potential
applications to different fields of astrophysics. In particular, they can be
used as independent reliable cosmic clocks, and can also provide valuable
information about the fundamental parameters of a wide variety of stellar
populations, like our Galaxy and open and globular clusters. In addition, the
high densities and temperatures characterizing white dwarfs allow to use these
stars as cosmic laboratories for studying physical processes under extreme
conditions that cannot be achieved in terrestrial laboratories. They can be
used to constrain fundamental properties of elementary particles such as axions
and neutrinos, and to study problems related to the variation of fundamental
constants.
In this work, we review the essentials of the physics of white dwarf stars.
Special emphasis is placed on the physical processes that lead to the formation
of white dwarfs as well as on the different energy sources and processes
responsible for chemical abundance changes that occur along their evolution.
Moreover, in the course of their lives, white dwarfs cross different
pulsational instability strips. The existence of these instability strips
provides astronomers with an unique opportunity to peer into their internal
structure that would otherwise remain hidden from observers. We will show that
this allows to measure with unprecedented precision the stellar masses and to
infer their envelope thicknesses, to probe the core chemical stratification,
and to detect rotation rates and magnetic fields. Consequently, in this work,
we also review the pulsational properties of white dwarfs and the most recent
applications of white dwarf asteroseismology.Comment: 85 pages, 28 figures. To be published in The Astronomy and
Astrophysics Revie
Supersymmetric Monojets at the Large Hadron Collider
Supersymmetric monojets may be produced at the Large Hadron Collider by the
process qg -> squark neutralino_1 -> q neutralino_1 neutralino_1, leading to a
jet recoiling against missing transverse momentum. We discuss the feasibility
and utility of the supersymmetric monojet signal. In particular, we examine the
possible precision with which one can ascertain the neutralino_1-squark-quark
coupling via the rate for monojet events. Such a coupling contains information
on the composition of the neutralino_1 and helps bound dark matter direct
detection cross-sections and the dark matter relic density of the neutralino_1.
It also provides a check of the supersymmetric relation between gauge couplings
and gaugino-quark-squark couplings.Comment: 46 pages, 10 figures. The appendix has been rewritten to correct an
error that appears in all previous versions of the appendix. This error has
no effect on the results in the main body of the pape
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Performance of two questionnaires to measure treatment adherence in patients with Type-2 Diabetes
<p>Abstract</p> <p>Background</p> <p>Most valid methods to measure treatment adherence require time and resources, and they are not easily applied in highly demanding Primary Health Care Clinics (PHCC). The objective of this study was to determine sensitivity, specificity, predictive values, likelihood ratios, and post-test probabilities of two novel questionnaires as proxy measurements of treatment adherence in Type-2 diabetic patients.</p> <p>Methods</p> <p>Two questionnaires were developed by a group of experts to identify the patient's medical prescription knowledge (knowledge) and their attitudes toward treatment adherence (attitudes) as proxy measurements of adherence. The questionnaires were completed by patients receiving care in PHCC pertaining to the Mexican Institute of Social Security in Aguascalientes (Mexico). Pill count was used as gold standard. Participants were selected randomly, and their oral hypoglycemic prescriptions were studied. The main outcome measures for each questionnaire were sensitivity, specificity, predictive values, likelihood ratios, and post-test probabilities, all as an independent questionnaire test and in a serial analysis.</p> <p>Results</p> <p>Adherence prevalence was 27.0% using pill count. Knowledge questionnaire showed the highest sensitivity (68.1%) and negative predictive value (82.2%), the lowest negative likelihood ratio (0.58) and post-test probability for a negative result (0.16). Serial analysis showed the highest specificity (77.4%) and positive predictive value (40.1%) as well as the highest positive likelihood ratio (1.8) and post-test probability for a positive result (0.39).</p> <p>Conclusion</p> <p>Medical Prescription Knowledge questionnaire showed the best performance as proxy measurement to identify non-adherence in type 2 diabetic patients regarding negative predictive value, negative likelihood ratio, and post-test probability for a negative result. However, Medical Prescription Knowledge questionnaire performance may change in contexts with higher adherence prevalence. Therefore, more research is needed before using this method in other contexts.</p
The search for transient astrophysical neutrino emission with IceCube-DeepCore
We present the results of a search for astrophysical sources of brief transient neutrino emission using IceCube and DeepCore data acquired between 2012 May 15 and 2013 April 30. While the search methods employed in this analysis are similar to those used in previous IceCube point source searches, the data set being examined consists of a sample of predominantly sub-TeV muon-neutrinos from the Northern Sky (-5 degrees < delta < 90 degrees) obtained through a novel event selection method. This search represents a first attempt by IceCube to identify astrophysical neutrino sources in this relatively unexplored energy range. The reconstructed direction and time of arrival of neutrino events are used to search for any significant self-correlation in the data set. The data revealed no significant source of transient neutrino emission. This result has been used to construct limits at timescales ranging from roughly 1 s to 10 days for generic soft-spectra transients. We also present limits on a specific model of neutrino emission from soft jets in core-collapse supernovae
Anomalous coupling effects in rare B- and K-meson decays
As a top-factory, the LHC is performing a direct study of top-quark anomalous
FCNC couplings, which are, however, correlated closely with the rare B- and
K-meson decays. In this paper, we study the effects of anomalous (with
) couplings in the rare decays , , , , and . With the up-to-date experimental bounds on the branching
ratios of these channels, constraints on the left-handed anomalous couplings
and are derived, respectively. With these low-energy
constraints taken into account, we find that, for real couplings and
, the indirect upper bounds on are much lower
than that from the D0 collaboration, but are still compatible with the
discovery potential of ATLAS with an integrated luminosity of . With refined measurements to be available at the LHCb, the
future super-B factories, the NA62 at CERN, and the KOTO at J-PARC, closer
correlations between the and the rare B- and K-meson decays are
expected in the near future, which will be helpful for the searches of the
top-quark FCNC decays at the LHC.Comment: 25 pages, 18 figures, 4 tables; More references added, version
published in JHE
The Effect of Pre-Analytical Variability on the Measurement of MRM-MS-Based Mid- to High-Abundance Plasma Protein Biomarkers and a Panel of Cytokines
Blood sample processing and handling can have a significant impact on the stability and levels of proteins measured in biomarker studies. Such pre-analytical variability needs to be well understood in the context of the different proteomics platforms available for biomarker discovery and validation. In the present study we evaluated different types of blood collection tubes including the BD P100 tube containing protease inhibitors as well as CTAD tubes, which prevent platelet activation. We studied the effect of different processing protocols as well as delays in tube processing on the levels of 55 mid and high abundance plasma proteins using novel multiple-reaction monitoring-mass spectrometry (MRM-MS) assays as well as 27 low abundance cytokines using a commercially available multiplexed bead-based immunoassay. The use of P100 tubes containing protease inhibitors only conferred proteolytic protection for 4 cytokines and only one MRM-MS-measured peptide. Mid and high abundance proteins measured by MRM are highly stable in plasma left unprocessed for up to six hours although platelet activation can also impact the levels of these proteins. The levels of cytokines were elevated when tubes were centrifuged at cold temperature, while low levels were detected when samples were collected in CTAD tubes. Delays in centrifugation also had an impact on the levels of cytokines measured depending on the type of collection tube used. Our findings can help in the development of guidelines for blood collection and processing for proteomic biomarker studies
The Environmental History of Cetaceans in Portugal: Ten Centuries of Whale and Dolphin Records
The history between cetaceans and humans is documented throughout time not only in reports, descriptions, and tales but also in legal documents, laws and regulations, and tithes. This wealth of information comes from the easy spotting and identification of individuals due to their large size, surface breathing, and conspicuous above water behaviour. This work is based on historical sources and accounts accounting for cetacean presence for the period between the 12th and 17th centuries, as well as scientific articles, newspapers, illustrations, maps, non-published scientific reports, and other grey literature from the 18th century onwards. Information on whale use in Portugal's mainland has been found since as early as the 12th century and has continued to be created throughout time. No certainty can be given for medieval and earlier events, but both scavenging of stranded whales or use of captured ones may have happened. There is an increasing number of accounts of sighted, stranded, used, or captured cetaceans throughout centuries which is clearly associated with a growing effort towards the study of these animals. Scientific Latin species denominations only started to be registered from the 18th century onwards, as a consequence of the evolution of natural sciences in Portugal and increasing interest from zoologists. After the 19th century, a larger number of observations were recorded, and from the 20th century to the present day, regular scientific records have been collected. Research on the environmental history of cetaceans in Portugal shows a several-centuries-old exploitation of whales and dolphins, as resources mainly for human consumption, followed in later centuries by descriptions of natural history documenting strandings and at sea encounters. Most cetaceans species currently thought to be present in Portuguese mainland waters were at some point historically recorded
- …