Uncertainty Estimates in Few-Body Physics

Uncertainty estimates in theoretical physics are just as important as they are in experimental physics. As a theorist, one must qualify a given calculation with the assumptions on which the calculation is performed. Such a practice equips the scientific community with the context necessary to evaluate the validity of a theory. It also provides some basis upon which the theory can develop improvements. The work presented here concerns itself with two sources of uncertainty in theoretical physics. First, we discuss numerical uncertainties. Particularly, we quantify the uncertainties introduced by basis truncations and the exploit it to extrapolate infinite-basis results. Second, we examine framework uncertainties — those attributable to the inherent failure of the employed model to describe the fullness of nature. We establish the sufficiency of a two-body contact interaction to renormalize short-distance physics in the two- and three-body sectors of systems where singular potentials relevant to nuclear and atomic dominate the low-energy behavior

Effective Field Theory for the Bound States and Scattering of a Heavy Charged Particle and a Neutral Atom

We show the system of a heavy charged particle and a neutral atom can be described by a low-energy effective field theory where the attractive $1/r^4$ induced dipole potential determines the long-distance/low-energy wave functions. The $1/r^4$ interaction is renormalized by a contact interaction at leading order. Derivative corrections to that contact interaction give rise to higher-order terms. We show that this ``Induced-dipole EFT'' (ID-EFT) reproduces the $\pi^+$-hydrogen phase shifts of a more microscopic potential, the Temkin-Lamkin potential, over a wide range of energies. Already at leading order it also describes the highest-lying excited bound states of the pionic-hydrogen ion. Lower-lying bound states receive substantial corrections at next-to-leading order, with the size of the correction proportional to their distance from the scattering threshold. Our next-to-leading order calculation shows that the three highest-lying bound states of the Temkin-Lamkin potential are well-described in ID-EFT

Perspective: Is It Time for Advocacy Training in Medical Education?

As the modern medical system becomes increasingly complex, a debate has arisen over the place of advocacy efforts within the medical profession. The authors argue that advocacy can help physicians fulfill their social contract. For physicians to become competent in patient-centered, clinical, administrative, or legislative advocacy, they require professional training. Many professional organizations have called for curricular reform to meet society's health needs during the past 30 years, and the inclusion of advocacy training in undergraduate, graduate, and continuing medical education is supported on both pragmatic and ethical grounds. Undergraduate medical education, especially, is an ideal time for this training because a standard competency can be instilled across all specialties. Although the Accreditation Council for Graduate Medical Education includes advocacy training in curricula for residency programs, few medical schools or residency programs have advocacy electives. By understanding the challenges of the health care system and how to change it for the better, physicians can experience increased professional satisfaction and effectiveness in improving patient care, systems-based practice, and public health

Assessing Errors Inherent in OCT-Derived Macular Thickness Maps

SD-OCT has become an essential tool for evaluating macular pathology; however several aspects of data collection and analysis affect the accuracy of retinal thickness measurements. Here we evaluated sampling density, scan centering, and axial length compensation as factors affecting the accuracy of macular thickness maps. Forty-three patients with various retinal pathologies and 113 normal subjects were imaged using Cirrus HD-OCT. Reduced B-scan density was associated with increased interpolation error in ETDRS macular thickness plots. Correcting for individual differences in axial length revealed modest errors in retinal thickness maps, while more pronounced errors were observed when the ETDRS plot was not positioned at the center of the fovea (which can occur as a result of errant fixation). Cumulative error can exceed hundreds of microns, even under “ideal observer” conditions. This preventable error is particularly relevant when attempting to compare macular thickness maps to normative databases or measuring the area or volume of retinal features

Toolglasses, marking menus, and hotkeys: a comparison of one and two-handed command selection techniques

This paper introduces a new input technique, bimanual marking menus, and compares its performance with five other techniques: static toolbars, hotkeys, grouped hotkeys, marking menus, and toolglasses. The study builds on previous work by setting the comparison in a commonly encountered task, shape drawing. In this context, grouped hotkeys and bimanual marking menus were found to be the fastest. Subjectively, the most preferred input method was bimanual marking menus. Toolglass performance was unexpectedly slow, which hints at the importance of low-level toolglass implementation choices. Key words: Bimanual interfaces, two-handed interfaces, toolglass, bimanual marking menus, command selection.

DESIGN, DEVELOPMENT AND FIELD DEPLOYMENT OF A TELEOPERATED SAMPLING SYSTEM

A teleoperated sampling system for the identification, collection and retrieval of samples following the detonation of an Improvised Nuclear Device (IND) or Radiological Dispersion Devise (RDD) has been developed and tested in numerous field exercises. The system has been developed as part of the Defense Threat Reduction Agency's (DTRA) National Technical Nuclear Forensic (NTNF) Program. The system is based on a Remotec ANDROS Mark V-A1 platform. Extensive modifications and additions have been incorporated into the platform to enable it to meet the mission requirements. The Defense Science Board Task Force on Unconventional Nuclear Warfare Defense, 2000 Summer Study Volume III report recommended the Department of Defense (DOD) improve nuclear forensics capabilities to achieve accurate and fast identification and attribution. One of the strongest elements of protection is deterrence through the threat of reprisal, but to accomplish this objective a more rapid and authoritative attribution system is needed. The NTNF program provides the capability for attribution. Early on in the NTNF program, it was recognized that there would be a desire to collect debris samples for analysis as soon as possible after a nuclear event. Based on nuclear test experience, it was recognized that mean radiation fields associated with even low yield events could be several thousand R/Hr near the detonation point for some time after the detonation. In anticipation of pressures to rapidly sample debris near the crater, considerable effort is being devoted to developing a remotely controlled vehicle that could enter the high radiation field area and collect one or more samples for subsequent analysis

C4B null alleles are not associated with genetic polymorphisms in the adjacent gene CYP21A2 in autism

<p>Abstract</p> <p>Background</p> <p>Research indicates that the etiology of autism has a strong genetic component, yet so far the search for genes that contribute to the disorder, including several whole genome scans, has led to few consistent findings. However, three studies indicate that the complement <it>C4B </it>gene null allele (i.e. the missing or nonfunctional <it>C4B </it>gene) is significantly more frequent in individuals with autism. Due to the close proximity of the <it>CYP21A2 </it>gene to the <it>C4B </it>locus (3 kb) it was decided to examine samples from autistic subjects, including many with known <it>C4B </it>null alleles for common <it>CYP21A2 </it>mutations.</p> <p>Methods</p> <p>Samples from subjects diagnosed with autism and non-autistic controls (controls) previously typed for <it>C4B </it>null alleles were studied. Allele specific polymerase chain reaction (PCR) methods were used to determine 8 of the most common <it>CYP21A2 </it>genetic mutations, known to completely or partially inhibit 21-hydroxylase, the enzyme encoded by the <it>CYP21A2 </it>gene.</p> <p>Results</p> <p>Although the combined autism and control study subjects had 50 <it>C4B </it>null alleles only 15 <it>CYP21A2 </it>mutations were detected in over 2250 genotypes. Eight mutations were detected in the autistic samples and 7 in the controls. The frequency of <it>CYP21A2 </it>mutations was similar between the autism and control samples. Only one individual (autistic) carried a chromosome containing both <it>C4B </it>null allele and <it>CYP21A2 </it>mutations.</p

Guidelines of the American Society of Mammalogists for the use of wild mammals in research

Guidelines for use of wild mammal species are updated from the American Society of Mammalogists (ASM) 2007 publication. These revised guidelines cover current professional techniques and regulations involving mammals used in research and teaching. They incorporate additional resources, summaries of procedures, and reporting requirements not contained in earlier publications. Included are details on marking, housing, trapping, and collecting mammals. It is recommended that institutional animal care and use committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals. These guidelines were prepared and approved by the ASM, working with experienced professional veterinarians and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals in their natural environments. The most current version of these guidelines and any subsequent modifications are available at the ASM Animal Care and Use Committee page of the ASM Web site (http://mammalsociety.org/committees/index.asp).American Society of Mammalogist