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Notes and Queries
W. J. ANDREW. ECORDS OF MERCHANT SHIPS. ... NOTES AND QUERIES. acess were TOWNLEY AND LANCASTER CASTLE, 1659. — During regrettable | alterations towards the end of last century for accommodation of the prisoners at Lan- caster Castle, a room was ...doi:10.1093/nq/158.24.425a fatcat:4gufflqmq5ey5pkgohha2na7zi
LANE W. LANCASTER UNIVERSITY OF NEBRASKA Training Youth for the New Social Order. By RUDOLPH R. REEDER. Yel low Springs, Ohio: Antioch Press, 1933. Pp. 248. $2.00. ... By CoLUMBUS ANDREWS. Chapel Hill: University of North Carolina Press, 1933. Pp. ix+245. $2.50. ...doi:10.1086/216805 fatcat:otyyd23gozcytpbsoiayuilivq
We would like to thank W. Preston for carefully reviewing the manuscript and making stylistic improvements. R.W. ... At the center of a uniform circular cylindrical object and under identical scanning and reconstruction conditions as described earlier, this is given by 23 w = ͱ 3a 2 MN D ͑0͒͑E ph ͒ 2 , ͑14͒ where w ... of 3, and second, their sigma is that of the absolute linear attenuation coefficient, whereas ours is for the relative attenuation coefficient with respect to water, which explains the additional term w ͑ ...doi:10.1118/1.1884906 pmid:15895588 fatcat:raps2orhtfhutkpddoolltdw7i
Purpose: In principle, a stationary digital breast tomosynthesis (s-DBT) system has better image quality when compared to continuous motion DBT systems due to zero motion blur of the source. The authors have developed a s-DBT system by using a linear carbon nanotube x-ray source array. The purpose of the current study was to quantitatively evaluate the performance of the s-DBT system; and investigate the dependence of imaging quality on the system configuration parameters. Methods: Physicaldoi:10.1118/1.4792296 pmid:23464332 pmcid:PMC3600660 fatcat:yg44nhih7beargpdostatw7b5a
more »... toms were used to assess the image quality of each configuration including inplane resolution as measured by the modulation transfer function (MTF), inplane contrast as measured by the signal difference to noise ratio (SdNR), and depth resolution as measured by the z-axis artifact spread function. Five parameters were varied to create five groups of configurations: (1) total angular span; (2) total number of projection images; (3) distribution of exposure (mAs) across the projection images; (4) entrance dose; (5) detector pixel size. Results: It was found that the z-axis depth resolution increased with the total angular span but was insensitive to the number of projection images, mAs distribution, entrance dose, and detector pixel size. The SdNR was not affected by the angular span or the number of projection images. A decrease in SdNR was observed when the mAs was not evenly distributed across the projection images. As expected, the SdNR increased with entrance dose and when larger pixel sizes were used. For a given detector pixel size, the inplane resolution was found to be insensitive to the total angular span, number of projection images, mAs distribution, and entrance dose. A 25% increase in the MTF was observed when the detector was operating in full resolution mode (70 μm pixel size) compared to 2 × 2 binned mode (140 μm pixel size). Conclusions: The results suggest that the optimal imaging configuration for a s-DBT system is a large angular span, an intermittent number of projection views, and a uniform mAs distribution over all views. With the detector operating at full resolution, a stationary DBT system can achieve an inplane resolution of 5.1 cycles per mm, which is significantly better than continuous motion DBT systems.
Purpose: The purpose of this investigation was to assess the angular dependence of a commercial optically stimulated luminescence dosimeter (OSLD) dosimetry system in MV x-ray beams at depths beyond d max and to find ways to mitigate this dependence for measurements in phantoms. Methods: Two special holders were designed which allow a dosimeter to be rotated around the center of its sensitive volume. The dosimeter's sensitive volume is a disk, 5 mm in diameter and 0.2 mm thick. The first holderdoi:10.1118/1.4875698 pmid:24877807 fatcat:iuulitls7ratzjrrcgoaryh7ym
more »... rotates the disk in the traditional way. It positions the disk perpendicular to the beam (gantry pointing to the floor) in the initial position (0 • ). When the holder is rotated the angle of the disk towards the beam increases until the disk is parallel with the beam ("edge on," 90 • ). This is referred to as Setup 1. The second holder offers a new, alternative measurement position. It positions the disk parallel to the beam for all angles while rotating around its center (Setup 2). Measurements with five to ten dosimeters per point were carried out for 6 MV at 3 and 10 cm depth. Monte Carlo simulations using GEANT4 were performed to simulate the response of the active detector material for several angles. Detector and housing were simulated in detail based on microCT data and communications with the manufacturer. Various material compositions and an all-water geometry were considered. Results: For the traditional Setup 1 the response of the OSLD dropped on average by 1.4% ± 0.7% (measurement) and 2.1% ± 0.3% (Monte Carlo simulation) for the 90 • orientation compared to 0 • . Monte Carlo simulations also showed a strong dependence of the effect on the composition of the sensitive layer. Assuming the layer to completely consist of the active material (Al 2 O 3 ) results in a 7% drop in response for 90 • compared to 0 • . Assuming the layer to be completely water, results in a flat response within the simulation uncertainty of about 1%. For the new Setup 2, measurements and Monte Carlo simulations found the angular dependence of the dosimeter to be below 1% and within the measurement uncertainty. Conclusions: The dosimeter system exhibits a small angular dependence of approximately 2% which needs to be considered for measurements involving other than normal incident beams angles.
Clostridium paradoxum strain JW-YL-7 is a moderately thermophilic anaerobic alkaliphile isolated from the municipal sewage treatment plant in Athens, GA. We report the near-complete genome sequence of C. paradoxum strain JW-YL-7 obtained by using PacBio DNA sequencing and Pilon for sequence assembly refinement with Illumina data.doi:10.1128/genomea.00229-16 pmid:27151784 pmcid:PMC4859166 fatcat:ebaba3isrffmtep4hekhzyyive
A 48-year-old pickleball player comes to the primary care clinic complaining of low back pain for 5 days. He was playing in a game when he reached for the ball and noted immediate sharp pain in his right lumbar region. He has been managing the pain with relative rest, alternating ice and heat, and appropriately dosed ibuprofen. However, he is concerned that the sharp pain has not resolved. He asks the provider to "get pictures" to make sure "everything is okay."doi:10.31486/toj.20.0077 pmid:33071654 pmcid:PMC7529135 fatcat:33c2ywlgcrgzzcemmrmeswsvpq
Dosimetry of ionizing radiation in the presence of strong magnetic fields is gaining increased relevance in light of advances for MRI-guided radiation therapy. While the impact of strong magnetic fields on the overall response of ionization chambers has been simulated and measured before, this work investigates the local impact of the magnetic field on dose response in an ion chamber. High-resolution 1D and 2D response maps have been created for two small clinical thimble ionization chambers,doi:10.1002/mp.13591 pmid:31087374 pmcid:PMC6852318 fatcat:p62nrvuseza3hef4qdcuoxvizm
more »... e PinPoint chambers 31006 and 31014 (Physikalisch Technische Werkstaetten Freiburg, Germany). Working on the Imaging and Medical Beam Line of the Australian Synchrotron an intense kilovoltage radiation beam with very low divergence, collimated to 0.1 mm was used to scan the chambers by moving them on a 2D motion platform. Measured current and beam position were correlated to create the response maps. Small neodymium magnets were used to create a field of about 0.25 T. Chamber axis, magnetic field, and beam direction were perpendicular to each other. Measurements were performed with both orientations of the magnetic field as well as without it. Chamber biases of 5 and 250 V in both polarities were used. The local distribution of the response of small thimble-type ionization chambers was found to be impacted by a magnetic field. Depending on the orientation of the magnetic field, the chamber response near the stem was either enhanced or reduced with the response near the tip behaving the opposite way. Local changes were in the order of up to 40% compared to measurements without the magnetic field present. Bending of the central electrode was observed for the chamber with the steel electrode. The size of the volume of reduced collection near the guard electrode was impacted by the magnetic field. As the here investigated beam and field parameters differ from those of clinical systems, quantitatively different results would be expected for the latter. However, the gyroradii encountered here were similar to those of a 6-7 MV MRI linac with a 1.5 T magnet. Magnetic fields impact the performance of ionization chambers also on a local level. For practical measurements this might mean a change in the effective point of measurement, in addition to any global corrections. Further knowledge about the local response will help in selecting or constructing optimized chambers for use in magnetic fields.
Iron is required for key metabolic processes but is toxic in excess. This circumstance forces organisms across the tree of life to tightly regulate iron homeostasis. In hypersaline lakes dominated by archaeal species, iron levels are extremely low and subject to environmental change; however, mechanisms regulating iron homeostasis in archaea remain unclear. In previous work, we demonstrated that two transcription factors (TFs), Idr1 and Idr2, collaboratively regulate aspects of iron homeostasisdoi:10.1093/nar/gkx662 pmid:28973467 pmcid:PMC5737653 fatcat:sl2mqnwdrzc4hhadzy4rzk56nm
more »... in the model species Halobacterium salinarum. Here we show that Idr1 and Idr2 are part of an extended regulatory network of four TFs of the bacterial DtxR family that maintains intracellular iron balance. We demonstrate that each TF directly regulates at least one of the other DtxR TFs at the level of transcription. Dynamical modeling revealed interlocking positive feedback loop architecture, which exhibits bistable or oscillatory network dynamics depending on iron availability. TF knockout mutant phenotypes are consistent with model predictions. Together, our results support that this network regulates iron homeostasis despite variation in extracellular iron levels, consistent with dynamical properties of interlocking feedback architecture in eukaryotes. These results suggest that archaea use bacterial-type TFs in a eukaryotic regulatory network topology to adapt to harsh environments.
We report on gallium droplet nucleation on silicon (100) substrates with and without the presence of the native oxide. The gallium deposition is carried out under ultra-high vacuum conditions at temperatures between 580 and 630°C. The total droplet volume, obtained from a fit to the diameter-density relation, is used for sample analysis on clean silicon surfaces. Through a variation of the 2D equivalent Ga thickness, the droplet diameter was found to be between 250-1000 nm. Longer annealingdoi:10.1088/0957-4484/26/31/315601 pmid:26184124 fatcat:yfbbko4wqjfiva3cvll7ge7ehm
more »... s resulted in a decrease of the total droplet volume. Substrate temperatures of 630°C and above led to Ga etching into the Si substrates and caused Si precipitation around the droplets. In contrast, we obtained an almost constant diameter distribution around 75 nm over a density range of more than two orders of magnitude in the presence of a native oxide layer. Furthermore, the droplet nucleation was found to correlate with the density of surface features on the 'epi-ready' wafer.
The power and flexibility of this metal-based approach makes it a valuable Ni-C2 Pb-C2 V-C1 Pb-C1 Co-C1 Ni-C1 Mo-C2 Mn-C1 Mo-C1 W-C2 10× U-C1 W-C1 NATURE LETTERS tool in unlocking a more complete ... The same conditions were used to investigate the release of Co, Ni, Mo, W and Zn from experimental samples. ...doi:10.1038/nature09265 pmid:20639861 fatcat:gccvjc7q3rbsze422zuw4lfdnq
Curiously, fliA1 insertion mutants had mildly positive fitness (w nitrate and w nitrite values of 0.2 and 0.3, respectively), while fliA2 had little effect (|w nitrate | and |w nitrite | of Ͻ0.09). ... | of Ͼ1 a Locus tag Gene annotation Fitness value Gene name w replete w 9 nM Mo w 700 nM Mo w 700 nM MoϪ9 nM Mo Psest_2543 Nitrate/sulfonate/bicarbonate transport ATPase Ϫ0.1 Ϫ0.2 Ϫ2.3 ...doi:10.1128/aem.02602-15 pmid:26452555 pmcid:PMC4702625 fatcat:r22a3the2vcthbl5pgerqjfsle
Section 1734 solely to indicate this fact. 1This project was supported in part by Contract W-7405-ENG-48 between Lawrence Livermore National Laboratory and the Department of Energy. 1The abbreviations ...pmid:3594446 fatcat:6dcipxxjezas7pp25wys27qzty
Al W/Rh and W/Ag W/Al W/Rh Filter material/thickness Mo: 0.03 mm 0.7 mm Al Rh: 0.05 mm 0.5 mm Al 0.05 mm Rh Rh: 0.025 mm Ag: 0.05 mm Tube voltage (kVp) Mo/Mo: 24-30 26-40 W/Rh: 23-35 26 ... -38 23-35 Mo/Rh: 26-32 W/Ag: 23-35 Rh/Rh: 26-40 TABLE III . ...doi:10.1118/1.4892600 pmid:25186375 fatcat:7trppexetzchfddzxjpr4qtyy4
Lancaster RW, Harris LD, Pearson D: Fifty-year old samples of progesterone demonstrate the complex role of synthetic impurities in stabilizing a metastable polymorph. CrystEngComm 2011, 13:1775. ...doi:10.1016/j.xphs.2016.06.009 pmid:27431013 fatcat:2zwway3pgbh2xay4bljykmddva
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