2,428 research outputs found
Perceived barriers to pediatrician and family practitioner participation in pediatric clinical trials: Findings from the Clinical Trials Transformation Initiative.
Despite legislation to stimulate pediatric drug development through clinical trials, enrolling children in trials continues to be challenging. Non-investigator (those who have never served as a clinical trial investigator) providers are essential to recruitment of pediatric patients, but little is known regarding the specific barriers that limit pediatric providers from participating in and referring their patients to clinical trials. We conducted an online survey of pediatric providers from a wide variety of practice types across the United States to evaluate their attitudes and awareness of pediatric clinical trials. Using a 4-point Likert scale, providers described their perception of potential barriers to their practice serving as a site for pediatric clinical trials. Of the 136 providers surveyed, 52/136 (38%) had previously referred a pediatric patient to a trial, and only 17/136 (12%) had ever been an investigator for a pediatric trial. Lack of awareness of existing pediatric trials was a major barrier to patient referral by providers, in addition to consideration of trial risks, distance to the site, and time needed to discuss trial participation with parents. Overall, providers perceived greater challenges related to parental concerns and parent or child logistical barriers than study implementation and ethics or regulatory barriers as barriers to their practice serving as a trial site. Providers who had previously been an investigator for a pediatric trial were less likely to be concerned with potential barriers than non-investigators. Understanding the barriers that limit pediatric providers from collaboration or inhibit their participation is key to designing effective interventions to optimize pediatric trial participation
Search for electric dipole moments at storage rings
Permanent electric dipole moments (EDMs) violate parity and time reversal
symmetry. Within the Standard Model (SM) they are many orders of magnitude
below present experimental sensitivity. Many extensions of the SM predict much
larger EDMs, which are therefore an excellent probe for the existence of "new
physics". Until recently it was believed that only electrically neutral systems
could be used for sensitive searches of EDMs. With the introduction of a novel
experimental method, high precision for charged systems will be within reach as
well. The features of this method and its possibilities are discussed.Comment: Proc. EXA2011, 6 pages;
http://www.springerlink.com/content/45l35376832vhrg0
Biodiesel Refining and Processing Strategies
Biodiesel fuel is produced from triglyceride fats, and oils obtained from plant and animal sources. Typically, triglycerides are first transesterified to produce fatty acid alkyl esters (FAAE) and then refined. Traditional FAAE refining strategies are often energy-intensive, requiring large amounts of water (e.g., wet washing), adsorbents, and/or chemicals. Refining, in turn, produces substantial amounts of waste and is accompanied by the loss of biodiesel as neutral oil entrained in waste. A wide array of methods and technologies have been developed for industrial oil purification. Successful refining practices minimize waste and limit neutral oil losses. Recent studies have explored the use of adsorbents, solvent purification processes, membrane filtration, as well as novel applications of electrostatic field treatments to remove polar impurities (including free fatty acids, residues, soaps, and glycerides), and particulates from oils. This chapter will review and compare traditional current and novel strategies for refining FAAE for use as biodiesel
Quantum systems in weak gravitational fields
Fully covariant wave equations predict the existence of a class of
inertial-gravitational effects that can be tested experimentally. In these
equations inertia and gravity appear as external classical fields, but, by
conforming to general relativity, provide very valuable information on how
Einstein's views carry through in the world of the quantum.Comment: 22 pages. To be published in Proceedings of the 17th Course of the
International School of Cosmology and Gravitation "Advances in the interplay
between quantum and gravity physics" edited by V. De Sabbata and A.
Zheltukhin, Kluwer Academic Publishers, Dordrech
Cleavage of functional IL-2 receptor alpha chain (CD25) from murine corneal and conjunctival epithelia by MMP-9
Expression of Th-1 Chemokines and Chemokine Receptors on the Ocular Surface of C57BL/6 Mice: Effects of Desiccating Stress
PURPOSE. To evaluate the effects of desiccating ocular surface stress on the expression of chemokines and their receptors by the corneal epithelium and conjunctiva of C57BL/6 and BALB/c mice. METHODS. Experimental dry eye was created in C57BL/6 and BALB/c mice. The concentrations of macrophage inflammatory protein 1␣ (MIP-1␣), MIP-1, monokine induced by interferon (MIG)-␥, and interferon-␥-inducible protein (IP)-10 in the corneal epithelia and conjunctiva were measured by a multiplex immunobead assay. Expression of MIP-1␣; MIP-1; regulated on activation, normal T-cell expressed and secreted (RANTES), MIG, IP-10; monocyte chemoattractant protein (MCP)-3; eotaxin-1; CCR5; CXCR3; and CCR3 in the cornea and conjunctiva were evaluated by real-time PCR and immunostaining. RESULTS. Desiccating stress significantly increased concentrations of MIP-1␣, MIP-1, IP-10, and MIG proteins in the corneal epithelium and conjunctiva of C57BL/6 mice. Furthermore, it increased levels of MIP-1␣, MIP-1, and CCR5 transcripts in the cornea and conjunctiva and RANTES, MIG, IP-10, and CXCR3 transcripts in the conjunctiva of C57BL/6 mice. In contrast, levels of MCP-3, eotaxin-1, and CCR3 transcripts increased in both tissues of BALB/c mice. In situ immunodetection of chemokines and their receptors was similar to their pattern of gene expression. CONCLUSIONS. Specific patterns of Th-1 and -2 chemokines and their receptors are induced in the mouse ocular surface by desiccating stress in a strain-related fashion. Desiccating stress potently stimulates the expression of Th-1 cell-attracting chemokines and chemokine receptors on the ocular surface of C57BL/6 mice. (Invest Ophthalmol Vis Sci
Quantum physics in inertial and gravitational fields
Covariant generalizations of well-known wave equations predict the existence
of inertial-gravitational effects for a variety of quantum systems that range
from Bose-Einstein condensates to particles in accelerators. Additional effects
arise in models that incorporate Born reciprocity principle and the notion of a
maximal acceleration. Some specific examples are discussed in detail.Comment: 25 pages,1 figure,to appear in "Relativity in Rotating Frame
Mass Antibiotic Treatment for Group A Streptococcus Outbreaks in Two Long-Term Care Facilities1
Outbreaks of invasive infections caused by group A β-hemolytic streptococcus (GAS) may occur in long-term care settings and are associated with a high case-fatality rate in debilitated adults. Targeted antibiotic treatment only to residents and staff known to be at specific risk of GAS may be an ineffective outbreak control measure. We describe two institutional outbreaks in which mass antibiotic treatment was used as a control measure. In the first instance, mass treatment was used after targeted antibiotic treatment was not successful. In the second instance, mass treatment was used to control a rapidly evolving outbreak with a high case-fatality rate. Although no further clinical cases were seen after the introduction of mass antibiotic treatment, persistence of the outbreak strain was documented in one institution >1 year after cases had ceased. Strain persistence was associated with the presence of a chronically colonized resident and poor infection control practices
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
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