High-accuracy differential image motion monitor measurements for the Thirty Meter Telescope site testing program

Differential image motion monitors (DIMMs) have become the industry standard for astronomical site characterization. The calibration of DIMMs is generally considered to be routine, but we show that particular care must be paid to this issue if high-accuracy measurements are to be achieved. In a side by side comparison of several DIMMs, we demonstrate that with proper care we can achieve an agreement between the seeing measurements of two DIMMS operating under the same conditions to better than +/-0.02 arc sec.     

Performance of the radphi detector and trigger in a high rate tagged photon beam

We describe the design and operation of a detector system for measuring all-photon decays of mesons photoproduced in a tagged photon beam with energies between 4.3 and 5.4 GeV and a flux of 5×10⁷ tagged photons per second. Photons from meson decays were detected with a lead-glass calorimeter with an energy resolution of 11% at 1 GeV. Various veto and trigger components were also present. Final states with as many as six photons were successfully detected and reconstructed.     

Cystic resolution: a performance metric for ultrasound imaging systems

This paper describes a metric that can be used to characterize the resolution of arbitrary broadband coherent imaging systems. The metric is particularly suited to medical ultrasound because it characterizes scanner performance using the contrast obtained by imaging anechoic cysts of various sizes that are embedded in a speckle-generating background, accounting for the effect of electronic noise. We present the theoretical derivation of the metric and provide simulation examples that demonstrate its utility. We use the metric to compare a low-cost, handheld, C-scan system under development in our laboratory to conventional ultrasound scanners. We also present the results of simulations that were designed to evaluate and optimize various parameters in our system, including the f/# and apodization windows. We investigate the impact of electronic noise on our system and quantify the tradeoffs associated with quantization in the analog to digital converter. Results indicate that an f/1 receive aperture combined with 10-bit precision and a signal-to-noise ratio (SNR) of 0 dB per channel would result in adequate image quality.     

The growth of Propionibacterium cyclohexanicum in fruit juices and its survival following elevated temperature treatments

This study investigated the growth of Propionibacterium cyclohexanicum in orange juice over a temperature range from 4 to 40 degrees C and its ability to multiply in tomato, grapefruit, apple, pineapple and cranberry juices at 30 and 35 degrees C. Survival after 10 min exposure to 50, 60, 70, 80, 85, 90 and 95 degrees C in culture medium and in orange juice was also assessed. In orange juice the organism was able to multiply by 2 logs at temperatures from 4 to 35 degrees C and survived for up to 52 days. However, at 40 degrees C viable counts were reduced after 6 days and no viable cells isolated after 17 days. The optimum growth temperature in orange juice over 6 days was 25 degrees C but over 4 days it was 35 degrees C. The growth of P. cyclohexanicum was monitored in tomato, grapefruit, cranberry, pineapple and apple juices at 30 and 35 degrees C over 29 days. Cranberry, grapefruit and apple juice did not support the growth of P. cyclohexanicum. At 30 degrees C no viable cells were detected after 8 days in cranberry juice or after 22 days in grapefruit juice while at 35 degrees C no viable cells were detected after 5 and 15 days, respectively. However, in apple juice, although a 5 log reduction occurred, viable cells could be detected after 29 days. P. cyclohexanicum was able to multiply in both tomato and pineapple juices. In tomato juice, there was a 2 log increase in viable counts after 8 days at 30 degrees C but no increase at 35 degrees C, while in pineapple juice there was a 1 log increase in numbers over 29 days with no significant difference between numbers of viable cells present at 30 and 35 degrees C. The organism survived at 50 degrees C for 10 min in culture medium without a significant loss of viability while similar treatment at 60, 70 and 80 degrees C resulted in approximately a 3-4 log reduction, with no viable cells detected after treatment at 85 or 90 or 95 degrees C but, when pre-treated at intermediate temperatures before exposure to higher temperatures, some cells survived. However, in orange juice a proportion of cells survived at 95 degrees C for 10 min without pre-treatment and there was no significant difference between numbers surviving with and without pre-treatment. The results from this study demonstrate that P. cyclohexanicum is able to grow in a number of juices, other than orange juice, and able to survive a number of high temperature procedures. Therefore, if initially present in the raw materials P. cyclohexanicum might survive the pasteurization procedures used in the fruit juice industry, contaminate and consequently spoil the final product.     

Effect of Dietary Cholesterol and Fat on Cell Cholesterol Transfer to Postprandial Plasma in Hyperlipidemic Men

Postprandial chylomicrons are potent ultimate acceptors of cell membrane cholesterol and are believed to accelerate reverse cholesterol transport (RCT). We compared the effects of meals rich in polyunsaturated fat (PUFA) and either high (605 mg) or low (151 mg) in cholesterol and a meal rich in dairy fat (DF) in the form of cream on net in vitro transport of red blood cell (RBC) membrane cholesterol to 4 and 6 h postprandial plasma in eight normotriglyceridemic (NTG-H) and eight hypertriglyceridemic (HTG-H) men with mild to moderate hypercholesterolemia. In HTG-H men, cell cholesterol accumulation in 6-h postprandial plasma was significantly (P = 0.02) less after the PUFA-HC meal compared with the other meals. The significant (P < 0.001) increase in cell plus endogenous cholesterol accumulation in the triglyceride-rich lipoprotein (TRL) fraction of 4 h postprandial plasma incubated with RBC was significantly (P = 0.007) higher after the PUFA-HC meal compared with DF meal in HTG-H men. In NTG-H men, cholesterol accumulation in plasma and plasma lipoproteins in the presence and absence of RBC was not significantly affected by the type of meal ingested. These data suggest that addition of large amounts of cholesterol to a PUFA meal may impair diffusion-mediated transport of cell membrane cholesterol to postprandial plasma and that replacing DF with PUFA in a meal increases postprandial lipemia and may potentially increase cholesterol accumulation in atherogenic postprandial TRL in HTG-H men.     

Predictive study of charge transport in disordered semiconducting polymers

We present a theoretical study of charge transport in disordered semiconducting polymers that relates the charge mobility to the chemical structure and the physical morphology in a novel multiscale approach. Our studies, focusing on poly(9,9-dioctylfluorene) (PFO), show that the charge mobility is dominated by pathways with the highest interchain charge-transfer rates. We also find that disorder is not always detrimental to charge transport. We find good agreement with experimental time-of-flight mobility data in highly aligned PFO films.     

Breast cancer cell-associated endopeptidase EC 24.11 modulates proliferative response to bombesin

We have investigated the production, growth and inactivation of gastrin-releasing peptide (GRP)-like peptides in human breast cancer cell lines. Radioimmunoassay detected GRP-like immunoreactivity (GRP-LI) in T47D breast cancer cells but not in the conditioned medium, indicating rapid clearance. No GRP-LI was found in the ZR-75-1 or MDA-MB-436 cells or their conditioned medium. High-performance liquid chromatography (HPLC) analysis of the GRP-LI in the T47D cells revealed a major peak, which co-eluted with GRP(18-27), and a minor more hydrophilic peak. In vitro stimulation of T47D cell growth by bombesin (BN) was enhanced to 138% of control levels (bombesin alone) by the addition of the selective endopeptidase EC 3.4.24.11 inhibitor phosphoramidon (0.1 ng ml(-1)). Fluorogenic analysis using whole cells confirmed low levels of this phosphoramidon-sensitive enzyme on the T47D cells. This enzyme, previously unreported in human breast cancer cells, significantly modulates both T47D growth and its response to BN-induced growth.     

Mild hypothermia as a protective therapy during intracranial aneurysm surgery: a randomized prospective pilot trial

OBJECTIVE: To conduct a pilot trial of mild intraoperative hypothermia during cerebral aneurysm surgery. METHODS: One hundred fourteen patients undergoing cerebral aneurysm clipping with (n = 52) (World Federation of Neurological Surgeons score < or =III) and without (n = 62) acute aneurysmal subarachnoid hemorrhage (SAH) were randomized to normothermic (target esophageal temperature at clip application of 36.5 degrees C) and hypothermic (target temperature of 33.5 degrees C) groups. Neurological status was prospectively evaluated before surgery, 24 and 72 hours postoperatively (National Institutes of Health Stroke Scale), and 3 to 6 months after surgery (Glasgow Outcome Scale). Secondary outcomes included postoperative critical care requirements, respiratory and cardiovascular complications, duration of hospitalization, and discharge disposition. RESULTS: Seven hypothermic patients (12%) could not be cooled to within 1 degrees C of target temperature; three of the seven were obese. Patients randomized to the hypothermic group more frequently required intubation and rewarming for the first 2 hours after surgery. Although not achieving statistical significance, patients with SAH randomized to the hypothermic group, when compared with patients in the normothermic group, had the following: 1) a lower frequency of neurological deterioration at 24 and 72 hours after surgery (21 versus 37-41%), 2) a greater frequency of discharge to home (75 versus 57%), and 3) a greater incidence of good long-term outcomes (71 versus 57%). For patients without acute SAH, there were no outcome differences between the temperature groups. There was no suggestion that hypothermia was associated with excess morbidity or mortality. CONCLUSION: Mild hypothermia during cerebral aneurysm surgery is feasible in nonobese patients and is well tolerated. Our results indicate that a multicenter trial enrolling 300 to 900 patients with acute aneurysmal SAH will be required to demonstrate a statistically significant benefit with mild intraoperative hypothermia.     

Analysis of amino and carboxy terminal GLUT-4 targeting motifs in 3T3-L1 adipocytes using an endosomal ablation technique

The targeting of the insulin-responsive glucose transporter, GLUT-4, to an intracellular compartment in adipocytes and muscle is one of the key features responsible for the unique insulin sensitivity of this transporter. Through expression of epitope-tagged GLUT-4 mutants in 3T3-L1 adipocytes, two motifs have been identified as playing a central role in GLUT-4 targeting: FQQI in the amino terminus and a di-leucine motif in the carboxy terminus. The goal of this study was to explore the role of these targeting motifs in the intracellular sorting of GLUT-4 using the Tf-HRP ablation technique. This technique provides a quantitative assessment of the amount of GLUT-4 located in recycling endosomes. In basal adipocytes, we find that approximately 40% of GLUT-4 is ablated following Tf-HRP loading. In contrast, here we demonstrate that the intracellular pool of a mutant in which F5 was mutated to A5 is localized to the recycling endosomal pathway, suggesting that the amino terminal FQQI motif functions in trafficking GLUT-4 from early endosomes. In contrast, GLUT-4 in which L489L490 was mutated to A489A490 was localized predominantly to a nonablated compartment. These data imply a role for the di-leucine motif in sorting from a separate intracellular compartment, such as the TGN. Our findings are discussed within the context of a revised multicompartment model for GLUT-4 trafficking in adipocytes, in which mutations in either the FQQI or LL motifs result in the altered subcellular trafficking of GLUT-4 between multiple intracellular compartments.     

Conserved domains in DNA repair proteins and evolution of repair systems

A detailed analysis of protein domains involved in DNA repair was performed by comparing the sequences of the repair proteins from two well-studied model organisms, the bacterium Escherichia coli and yeast Saccharomyces cerevisiae, to the entire sets of protein sequences encoded in completely sequenced genomes of bacteria, archaea and eukaryotes. Previously uncharacterized conserved domains involved in repair were identified, namely four families of nucleases and a family of eukaryotic repair proteins related to the proliferating cell nuclear antigen. In addition, a number of previously undetected occurrences of known conserved domains were detected; for example, a modified helix-hairpin-helix nucleic acid-binding domain in archaeal and eukaryotic RecA homologs. There is a limited repertoire of conserved domains, primarily ATPases and nucleases, nucleic acid-binding domains and adaptor (protein-protein interaction) domains that comprise the repair machinery in all cells, but very few of the repair proteins are represented by orthologs with conserved domain architecture across the three superkingdoms of life. Both the external environment of an organism and the internal environment of the cell, such as the chromatin superstructure in eukaryotes, seem to have a profound effect on the layout of the repair systems. Another factor that apparently has made a major contribution to the composition of the repair machinery is horizontal gene transfer, particularly the invasion of eukaryotic genomes by organellar genes, but also a number of likely transfer events between bacteria and archaea. Several additional general trends in the evolution of repair proteins were noticed; in particular, multiple, independent fusions of helicase and nuclease domains, and independent inactivation of enzymatic domains that apparently retain adaptor or regulatory functions.