Segmented back-up bar Patent

Segmented back-up bar for butt welding large tubular structures such as rocket booster bodies or tank

Novel clamps align large rocket cases, eliminate back-up bars

Welding clamps, placed inside and outside a rocket case, hold it in proper alignment during tungsten inert gas welding. These metal blocks, connected by a stainless steel band, eliminate the need for backup bars

Photographic Assessment of Change in Trichotillomania: Psychometric Properties and Variables Influencing Interpretation

Although photographic assessment has been found to be reliable in assessing hair loss in Trichotillomania, the validity of this method is unclear, particularly for gauging progress in treatment. The current study evaluated the psychometric properties of photographic assessment of change in Trichotillomania. Photographs showing hair loss of adults with Trichotillomania were taken before and after participating in a clinical trial for the condition. Undergraduate college students (N = 211) rated treatment response according to the photos, and additional archival data on hair pulling severity and psychosocial health were retrieved from the clinical trial. Photographic assessment of change was found to possess fair reliability (ICC = 0.53), acceptable criterion validity (r = 0.51), good concurrent validity (r = 0.30–0.36), and excellent incremental validity (ΔR2 = 8.67, p \u3c 0.01). In addition, photographic measures were significantly correlated with change in quality of life (r = 0.42), and thus could be considered an index of the social validity of Trichotillomania treatment. Gender of the photo rater and pulling topography affected the criterion validity of photographic assessment (partial η2 = 0.05–0.11). Recommendations for improving photographic assessment and future directions for hair pulling research are discussed

Subtleties on energy calculations in the image method

In this pedagogical work we point out a subtle mistake that can be done by undergraduate or graduate students in the computation of the electrostatic energy of a system containing charges and perfect conductors if they naively use the image method. Specifically, we show that the naive expressions for the electrostatic energy for these systems obtained directly from the image method are wrong by a factor 1/2. We start our discussion with well known examples, namely, point charge-perfectly conducting wall and point charge-perfectly conducting sphere and then proceed to the demonstration of general results, valid for conductors of arbitrary shapes.Comment: 9 pages, 2 figures; Major change in this version: subsection added to Sect.4 (theorem generalization). Minor changes: title replaced; corrections to the English; some explanatory comments adde

γ Heavy Chain Disease in Man: cDNA Sequence Supports Partial Gene Deletion Model

Human gamma heavy chain disease (HCD) is characterized by the presence in serum of a short monoclonal Ig gamma chain unattached to light chains. Although most HCD proteins have internal deletions, in some the defect is NH2-terminal. The OMM gamma 3 HCD serum protein is of the latter type, having undergone an extensive NH2-terminal deletion with a sequence starting within the hinge. A cell line synthesizing the OMM protein has enabled us to study the biogenesis of the abnormal molecule. In vitro translation of isolated mRNA yields a protein containing a hydrophobic NH2-terminal leader sequence. In the intact cell, the precursor molecule is processed normally to yield a protein with an NH2-terminal sequence homologous to the beginning of the variable (V) region. The nucleotide sequence of cDNA prepared from the OMM mRNA encodes a 19-amino acid leader followed by the first 15 residues of the V region. An extensive internal deletion encompasses the remainder of the V and the entire CHl domain. Immediately following the short V region, there is information in the cDNA for the entire normal hinge. The primary synthetic product is thus an internally deleted molecule that undergoes postsynthetic degradation to yield the NH2-terminally deleted serum protein. The structure of the OMM mRNA suggests that the protein abnormality results from a partial gene deletion rather than defective splicing

Thermal Plasticity of Diving Behavior, Aquatic Respiration, and Locomotor Performance in the Mary River Turtle Elusor macrurus

Locomotion is a common measure of performance used in studies of thermal acclimation because of its correlation with predator escape and prey capture. However, for sedentary animals such as freshwater turtles, we propose that diving behavior may be a more ecologically relevant measure of performance. Increasing dive duration in hatchling turtles reduces predator exposure and therefore functions as an ecological benefit. Diving behavior is thermally dependent, and in some species of freshwater turtles, it is also reliant on aquatic respiration. This study examined the influence of thermal acclimation on diving behavior, aquatic respiration, and locomotor performance in the endangered, bimodally respiring Mary River turtle Elusor macrurus. Diving behavior was found to partially acclimate at 17 degrees C, with turtles acclimated to a cold temperature (17 degrees C) having a significantly longer dive duration than hatchlings acclimated to a warm temperature (28 degrees C). This increase in dive duration at 17 degrees C was not a result of physiological alterations in metabolic rate but was due instead to an increase in aquatic oxygen consumption. Increasing aquatic oxygen consumption permitted cold-acclimated hatchlings to remain submerged for significantly longer periods, with one turtle undertaking a dive of over 2.5 d. When burst-swimming speed was used as the measure of performance, thermal acclimation was not detected. Overall, E. macrurus demonstrated a partial ability to acclimate to changes in environmental temperature

Development of outbred CD1 mouse colonies with distinct standardized gut microbiota profiles for use in complex microbiota targeted studies.

Studies indicate that the gut microbiota (GM) can significantly influence both local and systemic host physiologic processes. With rising concern for optimization of experimental reproducibility and translatability, it is essential to consider the GM in study design. However, GM profiles can vary between rodent producers making consistency between models challenging. To circumvent this, we developed outbred CD1 mouse colonies with stable, complex GM profiles that can be used as donors for a variety of GM transfer techniques including rederivation, co-housing, cross-foster, and fecal microbiota transfer (FMT). CD1 embryos were surgically transferred into CD1 or C57BL/6 surrogate dams that varied by GM composition and complexity to establish four separate mouse colonies harboring GM profiles representative of contemporary mouse producers. Using targeted 16S rRNA amplicon sequencing, subsequent female offspring were found to have similar GM profiles to surrogate dams. Furthermore, breeding colonies of CD1 mice with distinct GM profiles were maintained for nine generations, demonstrating GM stability within these colonies. To confirm GM stability, we shipped cohorts of these four colonies to collaborating institutions and found no significant variation in GM composition. These mice are an invaluable experimental resource that can be used to investigate GM effects on mouse model phenotype

Extraordinary sensitivity of the electronic structure and properties of single-walled carbon nanotubes to molecular charge-transfer

Interaction of single-walled carbon nanotubes with electron donor and acceptor molecules causes significant changes in the electronic and Raman spectra, the relative proportion of the metallic species increasing on electron donation through molecular charge transfer, as also verified by electrical resistivity measurements.Comment: 15 pages, 5 figurre

Electron heating mechanisms in dual frequency capacitive discharges

We discuss electron heating mechanisms in the sheath regions of dual-frequency capacitive discharges, with the twin aims of identifying the dominant mechanisms and supplying closed-form expressions from which the heating power can be estimated. We show that the heating effect produced by either Ohmic or collisionless heating is much larger when the discharge is excited by a superposition of currents at two frequencies than if either current had acted alone. This coupling effect occurs because the lower frequency current, while not directly heating the electrons to any great extent, strongly affects the spatial structure of the discharge in the sheath regions

Radio-frequency discharges in Oxygen. Part 1: Modeling

In this series of three papers we present results from a combined experimental and theoretical effort to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte-Carlo model on which the theoretical description is based will be described in the present paper. It treats space charge fields and transport processes on an equal footing with the most important plasma-chemical reactions. For given external voltage and pressure, the model determines the electric potential within the discharge and the distribution functions for electrons, negatively charged atomic oxygen, and positively charged molecular oxygen. Previously used scattering and reaction cross section data are critically assessed and in some cases modified. To validate our model, we compare the densities in the bulk of the discharge with experimental data and find good agreement, indicating that essential aspects of an oxygen discharge are captured.Comment: 11 pages, 10 figure