The Pitfalls of Constructing Yield Maps

Crop Production/Industries,

Accelerated Cardiac Diffusion Tensor Imaging Using Joint Low-Rank and Sparsity Constraints

Objective: The purpose of this manuscript is to accelerate cardiac diffusion tensor imaging (CDTI) by integrating low-rankness and compressed sensing. Methods: Diffusion-weighted images exhibit both transform sparsity and low-rankness. These properties can jointly be exploited to accelerate CDTI, especially when a phase map is applied to correct for the phase inconsistency across diffusion directions, thereby enhancing low-rankness. The proposed method is evaluated both ex vivo and in vivo, and is compared to methods using either a low-rank or sparsity constraint alone. Results: Compared to using a low-rank or sparsity constraint alone, the proposed method preserves more accurate helix angle features, the transmural continuum across the myocardium wall, and mean diffusivity at higher acceleration, while yielding significantly lower bias and higher intraclass correlation coefficient. Conclusion: Low-rankness and compressed sensing together facilitate acceleration for both ex vivo and in vivo CDTI, improving reconstruction accuracy compared to employing either constraint alone. Significance: Compared to previous methods for accelerating CDTI, the proposed method has the potential to reach higher acceleration while preserving myofiber architecture features which may allow more spatial coverage, higher spatial resolution and shorter temporal footprint in the future.Comment: 11 pages, 16 figures, published on IEEE Transactions on Biomedical Engineerin

In-situ monitoring of RO membranes using electrical impedance spectroscopy: Threshold fluxes and fouling

Electrical impedance spectroscopy (EIS) was employed to monitor RO membranes in-situ during crossflow filtration using a membrane module fitted with suitable electrodes. EIS spectra can be analyzed in terms of layers and processes that are associated with different electrical time constants. One such layer identified in the spectra is the AC diffusion polarization layer that forms at the surface of the membrane within the concentration polarization layer. The conductance, (GDP) of this layer provides an indication of the nature of the material accumulating very close to the surface. When the feed water contained inorganic foulants such as silica, the value of GDP gradually deceased as the silica (a poorly conducting material) accumulated on the surface. However, once a more integrated cake forms, the value of GDP rises as the decrease in the mass transport coefficient due to the cake, leads to an increase in the salt concentration in this region; the so called cake enhanced concentration polarization (CECP) effect. The inflection point of GDP vs time was itself dependent on the value of the flux (decreasing with increases in flux) and crossflow velocity (increasing with increasing crossflow). This mimics the variation of the “critical” flux observed in porous membranes such as MF. It would thus appear that the inflection point for GDP corresponds to a threshold phenomenon where accumulation changes to cake formation and that it is a relatively well defined phenomenon, at least under controlled experimental conditions. This threshold flux could also be discerned in flux-step experiments where the differential rate changes in TMP (transmembrane pressure) vs time displayed a similar inflection. The threshold flux so determined was indeed very close to that determined from the GDP profiles. The concept of a “Threshold” flux, its relation to cake formation and its detection using EIS could be used for in-situ monitoring of RO membranes to optimize performance of plants. That could either be achieved using a “Canary” crossflow membrane module (fitted with suitable electrodes) connected in a side stream of a RO train or by suitable modification of the spiral wound modules themselves. Field trials to evaluate the economics of this have begun

Unstable Nonradial Oscillations on Helium Burning Neutron Stars

Material accreted onto a neutron star can stably burn in steady state only when the accretion rate is high (typically super-Eddington) or if a large flux from the neutron star crust permeates the outer atmosphere. For such situations we have analyzed the stability of nonradial oscillations, finding one unstable mode for pure helium accretion. This is a shallow surface wave which resides in the helium atmosphere above the heavier ashes of the ocean. It is excited by the increase in the nuclear reaction rate during the oscillations, and it grows on the timescale of a second. For a slowly rotating star, this mode has a frequency of approximately 20-30 Hz (for l=1), and we calculate the full spectrum that a rapidly rotating (>>30 Hz) neutron star would support. The short period X-ray binary 4U 1820--30 is accreting helium rich material and is the system most likely to show this unstable mode,especially when it is not exhibiting X-ray bursts. Our discovery of an unstable mode in a thermally stable atmosphere shows that nonradial perturbations have a different stability criterion than the spherically symmetric thermal perturbations that generate type I X-ray bursts.Comment: Accepted for publication in Astrophysical Journal, 22 pages, 14 figure

Dose de-escalation of intrapleural tissue plasminogen activator therapy for pleural infection. The alteplase dose assessment for Pleural infection Therapy project

Rationale: Intrapleural therapy with a combination of tissue plasminogen activator (tPA) 10 mg and DNase 5 mg administered twice daily has been shown in randomized and open-label studies to successfully manage over 90% of patients with pleural infection without surgery. Potential bleeding risks associated with intrapleural tPA and its costs remain important concerns. The aim of the ongoing Alteplase Dose Assessment for Pleural infection Therapy (ADAPT) project is to investigate the efficacy and safety of dose de-escalation for intrapleural tPA. The first of several planned studies is presented here. Objectives: To evaluate the efficacy and safety of a reduced starting dose regimen of 5 mg of tPA with 5 mg of DNase administered intrapleurally for pleural infection. Methods: Consecutive patients with pleural infection at four participating centers in Australia, the United Kingdom, and New Zealand were included in this observational, open-label study. Treatment was initiated with tPA 5 mg and DNase 5 mg twice daily. Subsequent dose escalation was permitted at the discretion of the attending physician. Data relating to treatment success, radiological and systemic inflammatory changes (blood C-reactive protein), volume of fluid drained, length of hospital stay, and treatment complications were extracted retrospectively from the medical records. Results: We evaluated 61 patients (41 males; age, 57 ± 16 yr). Most patients (n = 58 [93.4%]) were successfully treated without requiring surgery for pleural infection. Treatment success was corroborated by clearance of pleural opacities visualized by chest radiography (from 42% [interquartile range, 22–58] to 16% [8–31] of hemithorax; P < 0.001), increase in pleural fluid drainage (from 175 ml in the 24 h preceding treatment to 2,025 ml [interquartile range, 1,247–2,984] over 72 h of therapy; P <  0.05) and a reduction in blood C-reactive protein (P < 0.05). Seven patients (11.5%) had dose escalation of tPA to 10 mg. Three patients underwent surgery. Three patients (4.9%) received blood transfusions for gradual pleural blood loss; none were hemodynamically compromised. Pain requiring escalation of analgesia affected 36% of patients; none required cessation of therapy. Conclusions: These pilot data suggest that a starting dose of 5 mg of tPA administered intrapleurally twice daily in combination with 5 mg of DNase for the treatment of pl

Multiscale Variability in North American Summer Maximum Temperatures and Modulations from the North Atlantic Simulated by an AGCM

Six recurrent thermal regimes are identified over continental North America from June to September through a k-means clustering applied to daily maximum temperature simulated by ECHAM5 forced by his- torical SSTs for 1930–2013 and validated using NCEP–DOE AMIP-II reanalysis over the 1980–2009 period. Four regimes are related to a synoptic wave pattern propagating eastward in the midlatitudes with embedded ridging anomalies that translate into maximum warming transiting along. Two other regimes, associated with broad continental warming and above average temperatures in the northeastern United States, respectively, are characterized by ridging anomalies over North America, Europe, and Asia that suggest correlated heat wave occurrences in these regions. Their frequencies are mainly related to both La Niña and warm conditions in the North Atlantic. Removing all variability beyond the seasonal cycle in the North Atlantic in ECHAM5 leads to a significant drop in the occurrences of the regime associated with warming in the northeastern United States. Superimposing positive (negative) anomalies mimicking the Atlantic multidecadal variability (AMV) in the North Atlantic translates into more (less) warming over the United States across all regimes, and does alter regime frequencies but less significantly. Regime frequency changes are thus primarily controlled by Atlantic SST variability on all time scales beyond the seasonal cycle, rather than mean SST changes, whereas the in- tensity of temperature anomalies is impacted by AMV SST forcing, because of upper-tropospheric warming and enhanced stability suppressing rising motion during the positive phase of the AMV

Cloning and expression of an insect Ca2+-ATPase from Heliothis virescens

AbstractA complementary DNA for the Tobacco Budworm, Heliothis virescens, sarco(endo)plasmic reticulum-type Ca2+-ATPase (HVSERCA) has been cloned and sequenced. cDNA fragments of adult rabbit fast-twitch muscle Ca2+-ATPase (SERCA1a) were used as heterologous probes to isolate a partial cDNA clone coding for a protein with high homology to the Ca2+-ATPase from Drosophila melanogaster (DRSERCA) and vertebrate ER/SR Ca2+ pumps. The entire cDNA clone contains an ORF encoding a protein of 1000 amino acids which shares the characteristic motifs of a P-type ATPase. HVSERCA shares 89% identity with DRSERCA, 80% identity with the Artemia Ca2+-ATPase and 72% identity with avian and mammalian SERCAs. An insect Ca2+-ATPase-specific polyclonal antiserum has been raised against a fusion protein containing sequence from the cytoplasmic domain of HVSERCA. Heterologous expression of the insect pump in COS-7 cells has been demonstrated by immunocytochemistry and the reticular pattern of staining is consistent with an ER localisation. However, the expressed enzyme from COS-7 cells does not appear to be active

General Algorithm For Improved Lattice Actions on Parallel Computing Architectures

Quantum field theories underlie all of our understanding of the fundamental forces of nature. The are relatively few first principles approaches to the study of quantum field theories [such as quantum chromodynamics (QCD) relevant to the strong interaction] away from the perturbative (i.e., weak-coupling) regime. Currently the most common method is the use of Monte Carlo methods on a hypercubic space-time lattice. These methods consume enormous computing power for large lattices and it is essential that increasingly efficient algorithms be developed to perform standard tasks in these lattice calculations. Here we present a general algorithm for QCD that allows one to put any planar improved gluonic lattice action onto a parallel computing architecture. High performance masks for specific actions (including non-planar actions) are also presented. These algorithms have been successfully employed by us in a variety of lattice QCD calculations using improved lattice actions on a 128 node Thinking Machines CM-5. {\underline{Keywords}}: quantum field theory; quantum chromodynamics; improved actions; parallel computing algorithms