2,172 research outputs found
Design of Complex Wavelet Pulses Enabling PSK Modulation for UWB Impulse Radio Communications
In this paper, we present the design of complex Ultra-wideband (UWB) pulses which enables the phase-shift keying (PSK) modulation for UWB Impulse Radio (IR) Communications. Two classes of complex UWB pulses are proposed based on complex Gaussian wavelets and complex rational orthogonal wavelets respectively. Formulas in closed form are derived for a full control of the time and frequency properties of the designed UWB pulses. The system characterisation of the complex UWB pulse-based PSK modulation and demodulation is presented.A novel PSK demodulator based on complex wavelet signalling is adopted for its unique robustness against timing jitter. Besides the inherent advantages of PSK modulation which lead to high power efficiency and high data rate, the proposed PSK scheme in the UWB communication context provides a more flexible way to construct new UWB modulation schemes by combining PSK with other basic modulation options such as the pulse amplitude modulation (PAM) and the pulse position modulation (PPM). In addition, based on the derived formulas, the proposed UWB pulse design method also provides a solution to the construction of multiband UWB systems
Automatic estimation of harmonic tension by distributed representation of chords
The buildup and release of a sense of tension is one of the most essential
aspects of the process of listening to music. A veridical computational model
of perceived musical tension would be an important ingredient for many music
informatics applications. The present paper presents a new approach to
modelling harmonic tension based on a distributed representation of chords. The
starting hypothesis is that harmonic tension as perceived by human listeners is
related, among other things, to the expectedness of harmonic units (chords) in
their local harmonic context. We train a word2vec-type neural network to learn
a vector space that captures contextual similarity and expectedness, and define
a quantitative measure of harmonic tension on top of this. To assess the
veridicality of the model, we compare its outputs on a number of well-defined
chord classes and cadential contexts to results from pertinent empirical
studies in music psychology. Statistical analysis shows that the model's
predictions conform very well with empirical evidence obtained from human
listeners.Comment: 12 pages, 4 figures. To appear in Proceedings of the 13th
International Symposium on Computer Music Multidisciplinary Research (CMMR),
Porto, Portuga
A variety of environmentally persistent chemicals, including some phthalate plasticizers, are weakly estrogenic
Sewage, a complex mixture of organic and inorganic chemicals, is considered to be a major source of environmental pollution. A random screen of 20 organic man-made chemicals present in liquid effluents revealed that half appeared able to interact with the estradiol receptor. This was demonstrated by their ability to inhibit binding of 17 beta-estradiol to the fish estrogen receptor. Further studies, using mammalian estrogen screens in vitro, revealed that the two phthalate esters butylbenzyl phthalate (BBP) and di-n-butylphthalate (DBP) and a food antioxidant, butylated hydroxyanisole (BHA) were estrogenic; however, they were all less estrogenic than the environmental estrogen octylphenol. Phthalate esters, used in the production of various plastics (including PVC), are among the most common industrial chemicals. Their ubiquity in the environment and tendency to bioconcentrate in animal fat are well known. Neither BBP nor DBP were able to act as antagonists, indicating that, in the presence of endogenous estrogens, their overall effect would be cumulative. Recently, it has been suggested that environmental estrogens may be etiological agents in several human diseases, including disorders of the male reproductive tract and breast and testicular cancers. The current finding that some phthalate compounds and some food additives are weakly estrogenic in vitro, needs to be supported by further studies on their effects in vivo before any conclusions can be made regarding their possible role in the development of these condition
The prognostic significance of tumour-stroma ratio in oestrogen receptor-positive breast cancer
BACKGROUND:
A high percentage of stroma predicts poor survival in triple-negative breast cancers but is diminished in studies of unselected cases. We determined the prognostic significance of tumour-stroma ratio (TSR) in oestrogen receptor (ER)-positive male and female breast carcinomas.
METHODS:
TSR was measured in haematoxylin and eosin-stained tissue sections (118 female and 62 male). Relationship of TSR (cutoff 49%) to overall survival (OS) and relapse-free survival (RFS) was analysed.
RESULTS:
Tumours with ≥49% stroma were associated with better survival in female (OS P=0.008, HR=0.2-0.7; RFS P=0.006, HR=0.1-0.6) and male breast cancer (OS P=0.005, HR=0.05-0.6; RFS P=0.01, HR=0.87-5.6), confirmed in multivariate analysis.
CONCLUSIONS:
High stromal content was related to better survival in ER-positive breast cancers across both genders, contrasting data in triple-negative breast cancer and highlighting the importance of considering ER status when interpreting the prognostic value of TSR
Consensus statement on the use of high sensitivity cardiac troponins
The increased sensitivity of high sensitivity cardiac troponin assays comes at a cost of decreased specificity, and “false positive” diagnosis of acute coronary syndromes has made clinicians wary of their use, fearing unnecessary hospitalisations, angiography and revascularisation. The Ethics and Guidelines Standing Committee of SA Heart Association convened a meeting of cardiologists, chemical pathologists, emergency medicine specialists and industry representatives to discuss the role of high sensitivity troponin (hsTn) testing. An international expert provided guidance, and this Consensus Statement is the product of that meeting. It is recommended that hsTn assays be widely adopted as the preferred biomarker for diagnosis of myocardial infarction. Pathology laboratories will standardise the units of measurement and the reporting of results. Rules for interpretation of results and algorithms for their application are provided. Separate algorithms apply to troponin T and troponin I, and the several troponin I assays on the market each have different numerical values. Use of high sensitivity troponin assays will result in earlier diagnosis of myocardial infarction, more reliable ruling out of myocardial infarction, and shortening of chest pain triage (to 4 hours), compared to former assays
Measurement Properties of Questionnaires Assessing Complementary and Alternative Medicine Use in Pediatrics: A Systematic Review
Complementary and alternative medicine (CAM) is commonly used by children, but estimates of that use vary widely partly due to the range of questionnaires used to assess CAM use. However, no studies have attempted to appraise measurement properties of these questionnaires. The aim of this systematic review was to critically appraise and summarize measurement properties of questionnaires of CAM use in pediatrics.A search strategy was implemented in major electronic databases in March 2011 and conference websites, scientific journals and experts were consulted. Studies were included if they mentioned a questionnaire assessing the prevalence of CAM use in pediatrics. Members of the team independently rated the methodological quality of the studies (using the COSMIN checklist) and measurement properties of the questionnaires (using the Terwee and Cohen criteria).A total of 96 CAM questionnaires were found in 104 publications. The COSMIN checklist showed that no studies reported adequate methodological quality. The Terwee criteria showed that all included CAM questionnaires had indeterminate measurement properties. According to the Cohen score, none were considered to be a well-established assessment, two approached the level of a well-established assessment, seven were promising assessments and the remainder (n = 87) did not reach the score's minimum standards.None of the identified CAM questionnaires have been thoroughly validated. This systematic review highlights the need for proper validation of CAM questionnaires in pediatrics, which may in turn lead to improved research and knowledge translation about CAM in clinical practice
Documenting the NICU design dilemma: comparative patient progress in open-ward and single family room units
Objective:To test the efficacy of single family room (SFR) neonatal intensive care unit (NICU) designs, questions regarding patient medical progress and relative patient safety were explored. Addressing these questions would be of value to hospital staff, administrators and designers alike. Study Design:This prospective study documented, by means of Institution Review Board-approved protocols, the progress of patients in two contrasting NICU designs. Noise levels, illumination and air quality measurements were included to define the two NICU physical environments. Result:Infants in the SFR unit had fewer apneic events, reduced nosocomial sepsis and mortality, as well as earlier transitions to enteral nutrition. More mothers sustained stage III lactation, and more infants were discharged breastfeeding in the SFR. Conclusion:This study showed the SFR to be more conducive to family-centered care, and to enhance infant medical progress and breastfeeding success over that of an open ward
SPACE for physical activity - a multicomponent intervention study: study design and baseline findings from a cluster randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>The aim of the School site, Play Spot, Active transport, Club fitness and Environment (SPACE) Study was to develop, document, and assess a comprehensive intervention in local school districts that promote everyday physical activity (PA) among 11-15-year-old adolescents. The study is based on a social ecological framework, and is designed to implement organizational and structural changes in the physical environment.</p> <p>Methods/design</p> <p>The SPACE Study used a cluster randomized controlled study design. Twenty-one eligible schools in the Region of Southern Denmark were matched and randomized in seven pairs according to eight matching variables summarized in an audit tool (crow-fly distance from residence to school for 5-6<sup>th </sup>graders; area household income; area education level; area ethnicity distribution; school district urbanity; condition and characteristics of school outdoor areas; school health policy; and active transport in the local area). Baseline measurements with accelerometers, questionnaires, diaries, and physical fitness tests were obtained in Spring 2010 in 5-6<sup>th </sup>grade in 7 intervention and 7 control schools, with follow-up measurements to be taken in Spring 2012 in 7-8<sup>th </sup>grade. The primary outcome measure is objective average daily physical activity and will be supported by analyses of time spent in moderate to vigorous activity and time spent sedentary. Other secondary outcome measures will be obtained, such as, overweight, physical fitness, active commuting to/from school and physical activity in recess periods.</p> <p>Discussion</p> <p>A total of 1348 adolescents in 5-6<sup>th </sup>grade in the Region of Southern Denmark participated at baseline (n = 14 schools). The response rate was high in all type of measurements (72.6-97.4%). There were no significant differences between intervention and control groups at baseline according to selected background variables and outcome measures: gender (p = .54), age (p = .17), BMI (p = .59), waist circumference (p = .17), physical fitness (p = .93), and physical activity (accelerometer) (p = .09).</p> <p>The randomization and matched pair design produced equivalent groups according to central outcome measures and background variables. The SPACE for physical activity Study will provide new insights on the effectiveness of multicomponent interventions to improve adolescents' physical activity level.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN79122411">ISRCTN79122411</a></p
Non-thermal emission processes in massive binaries
In this paper, I present a general discussion of several astrophysical
processes likely to play a role in the production of non-thermal emission in
massive stars, with emphasis on massive binaries. Even though the discussion
will start in the radio domain where the non-thermal emission was first
detected, the census of physical processes involved in the non-thermal emission
from massive stars shows that many spectral domains are concerned, from the
radio to the very high energies.
First, the theoretical aspects of the non-thermal emission from early-type
stars will be addressed. The main topics that will be discussed are
respectively the physics of individual stellar winds and their interaction in
binary systems, the acceleration of relativistic electrons, the magnetic field
of massive stars, and finally the non-thermal emission processes relevant to
the case of massive stars. Second, this general qualitative discussion will be
followed by a more quantitative one, devoted to the most probable scenario
where non-thermal radio emitters are massive binaries. I will show how several
stellar, wind and orbital parameters can be combined in order to make some
semi-quantitative predictions on the high-energy counterpart to the non-thermal
emission detected in the radio domain.
These theoretical considerations will be followed by a census of results
obtained so far, and related to this topic... (see paper for full abstract)Comment: 47 pages, 5 postscript figures, accepted for publication in Astronomy
and Astrophysics Review. Astronomy and Astrophysics Review, in pres
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