521 research outputs found
Microperforated leaf blotting on polyvinylidene difluoride and nylon membranes to analyze spatial distribution of endogenous and viral gene expression in plant leaves
Leaf blotting to detect proteins and investigate their spatial distribution in leaves has so far mainly been used to detect viral coat proteins that accumulate abundantly in infected leaves, but rarely to detect endogenous plant proteins. We improved the method for detecting endogenous proteins. We found that microperforating leaves with bundled pins before blotting, then pressing leaves with a rolling pin onto polyvinylidene difluoride (PVDF) membranes enabled even blotting of sap. This microperforated leaf blotting (mPLB) was also suitable for use with nylon membranes to detect leaf RNA. The mPLB revealed that accumulation of two endogenous proteins, calmodulin-like rgs-CaM and actin, was respectively positively and negatively associated with that of viral coat protein in tobacco leaves infected with cucumber mosaic virus (CMV). When a tobacco plant primed with benzothiadiazole was inoculated with CMV, mPLB showed that the infection was restricted to some areas of the leaf, and that in these areas the mRNA encoding tobacco pathogenesis-related protein 1, an indicator of salicylic acid-mediated immune responses, was induced. These results demonstrate the effectiveness of mPLB for investigating the spatial distribution of endogenous and viral gene expression in leaves
Performance Evaluation of HYCOM-GOM for Hydrokinetic Resource Assessment in the Florida Strait
The U.S. Department of Energy (DoE) is assessing and mapping the potential off-shore ocean current hydrokinetic energy resources along the U.S. coastline, excluding tidal currents, to facilitate market penetration of water power technologies. This resource assessment includes information on the temporal and three-dimensional spatial distribution of the daily averaged power density, and the overall theoretical hydrokinetic energy production, based on modeled historical simulations spanning a 7-year period of record using HYCOM-GOM, an ocean current observation assimilation model that generates a spatially distributed three-dimensional representation of daily averaged horizontal current magnitude and direction time series from which power density time series and their statistics can be derived. This study ascertains the deviation of HYCOM-GOM outputs, including transport (flow) and power density, from outputs based on three independent observation sources to evaluate HYCOM-GOM performance. The three independent data sources include NOAA s submarine cable data of transport, ADCP data at a high power density location, and HF radar data in the high power density region of the Florida Strait. Comparisons with these three independent observation sets indicate discrepancies with HYCOM model outputs, but overall indicate that the HYCOM-GOM model can provide an adequate assessment of the ocean current hydrokinetic resource in high power density regions like the Florida Strait. Additional independent observational data, in particular stationary ADCP measurements, would be useful for expanding this model performance evaluation study. ADCP measurements are rare in ocean environments not influenced by tides, and limited to one location in the Florida Strait. HF radar data, although providing great spatial coverage, is limited to surface currents only
Chiral primary cubic interactions from pp-wave supergravity
We explicitly construct cubic interaction light-cone Hamiltonian for the
chiral primary system involving the metric fields and the self-dual four-form
fields in the IIB pp-wave supergravity. The background fields representing
pp-waves exhibit SO(4)*SO(4)*Z_2 invariance. It turns out that the interaction
Hamiltonian is precisely the same as that for the dilaton-axion system, except
for the fact that the chiral primary system fields have the opposite parity to
that of the dilaton-axion fields under the Z_2 transformation that exchanges
two SO(4)'s.Comment: 14 pages, A few comments are adde
Gauge Symmetry Enhancement and Radiatively Induced Mass in the Large N Nonlinear Sigma Model
We consider a hybrid of nonlinear sigma models in which two complex
projective spaces are coupled with each other under a duality. We study the
large N effective action in 1+1 dimensions. We find that some of the
dynamically generated gauge bosons acquire radiatively induced masses which,
however, vanish along the self-dual points where the two couplings
characterizing each complex projective space coincide. These points correspond
to the target space of the Grassmann manifold along which the gauge symmetry is
enhanced, and the theory favors the non-Abelian ultraviolet fixed point.Comment: 11 pages, REVTEX, typos are corrected, version to appear in Phys.
Rev.
Subaru Hyper Suprime-Cam Survey for An Optical Counterpart of GW170817
We perform a -band survey for an optical counterpart of a binary neutron
star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted
transient search covers deg corresponding to the credible
region of GW170817 and reaches the completeness magnitude of mag
on average. As a result, we find 60 candidates of extragalactic transients,
including J-GEM17btc (a.k.a. SSS17a/DLT17ck). While J-GEM17btc is associated
with NGC 4993 that is firmly located inside the 3D skymap of GW170817, the
other 59 candidates do not have distance information in the GLADE v2 catalog or
NASA/IPAC Extragalactic Database (NED). Among 59 candidates, 58 are located at
the center of extended objects in the Pan-STARRS1 catalog, while one candidate
has an offset. We present location, -band apparent magnitude, and time
variability of the candidates and evaluate the probabilities that they are
located inside of the 3D skymap of GW170817. The probability for J-GEM17btc is
being much higher than those for the other 59 candidates
(). Furthermore, the possibility, that at
least one of the other 59 candidates is located within the 3D skymap, is only
. Therefore, we conclude that J-GEM17btc is the most-likely and
distinguished candidate as the optical counterpart of GW170817.Comment: 14 pages, 9 figures. Accepted for publication in PASJ (Publications
of the Astronomical Society of Japan
A review on experimental surgical models and anesthetic protocols of heart failure in rats
Heart failure (HF) is a serious health and economic burden worldwide, and its prevalence is continuously increasing. Current medications effectively moderate the progression of symptoms, and there is a need for novel preventative and reparative treatments. The development of novel HF treatments requires the testing of potential therapeutic procedures in appropriate animal models of HF. During the past decades, murine models have been extensively used in fundamental and translational research studies to better understand the pathophysiological mechanisms of HF and develop more effective methods to prevent and control congestive HF. Proper surgical approaches and anesthetic protocols are the first steps in creating these models, and each successful approach requires a proper anesthetic protocol that maintains good recovery and high survival rates after surgery. However, each protocol may have shortcomings that limit the study's outcomes. In addition, the ethical regulations of animal welfare in certain countries prohibit the use of specific anesthetic agents, which are widely used to establish animal models. This review summarizes the most common and recent surgical models of HF and the anesthetic protocols used in rat models. We will highlight the surgical approach of each model, the use of anesthesia, and the limitations of the model in the study of the pathophysiology and therapeutic basis of common cardiovascular diseases
Novel protocol to establish the myocardial infarction model in rats using a combination of medetomidine-midazolam-butorphanol (MMB) and atipamezole
BackgroundMyocardial infarction (MI) is one of the most common cardiac problems causing deaths in humans. Previously validated anesthetic agents used in MI model establishment are currently controversial with severe restrictions because of ethical concerns. The combination between medetomidine, midazolam, and butorphanol (MMB) is commonly used in different animal models. The possibility of MMB combination to establish the MI model in rats did not study yet which is difficult because of severe respiratory depression and delayed recovery post-surgery, resulting in significant deaths. Atipamezole is used to counter the cardiopulmonary suppressive effect of MMB.ObjectivesThe aim of the present study is to establish MI model in rats using a novel anesthetic combination between MMB and Atipamezole.Materials and methodsTwenty-five Sprague Dawley (SD) rats were included. Rats were prepared for induction of the Myocardial infarction (MI) model through thoracotomy. Anesthesia was initially induced with a mixture of MMB (0.3/5.0/5.0 mg/kg/SC), respectively. After endotracheal intubation, rats were maintained with isoflurane 1% which gradually reduced after chest closing. MI was induced through the left anterior descending (LAD) artery ligation technique. Atipamezole was administered after finishing all surgical procedures at a dose rate of 1.0 mg/kg/SC. Cardiac function parameters were evaluated using ECG (before and after atipamezole administration) and transthoracic echocardiography (before and 1 month after MI induction) to confirm the successful model. The induction time, operation time, and recovery time were calculated. The success rate of the MI model was also calculated.ResultsMI was successfully established with the mentioned anesthetic protocol through the LAD ligation technique and confirmed through changes in ECG and echocardiographic parameters after MI. ECG data was improved after atipamezole administration through a significant increase in heart rate (HR), PR Interval, QRS Interval, and QT correction (QTc) and a significant reduction in RR Interval. Atipamezole enables rats to recover voluntary respiratory movement (VRM), wakefulness, movement, and posture within a very short time after administration. Echocardiographic ally, MI rats showed a significant decrease in the left ventricular wall thickness, EF, FS, and increased left ventricular diastolic and systolic internal diameter. In addition, induction time (3.440 ± 1.044), operation time (29.40 ± 3.663), partial recovery time (10.84 ± 3.313), and complete recovery time (12.36 ± 4.847) were relatively short. Moreover, the success rate of the anesthetic protocol was 100%, and all rats were maintained for 1 month after surgery with a survival rate of 88%.ConclusionOur protocol produced a more easy anesthetic effect and time-saving procedures with a highly successful rate in MI rats. Subcutaneous injection of Atipamezole efficiently counters the cardiopulmonary side effect of MMB which is necessary for rapid recovery and subsequently enhancing the survival rate during the creation of the MI model in rats
Duality and Enhanced Gauge Symmetry in 2+1 Dimensions
We investigate the enlarged CP(N) model in 2+1 dimensions. This is a hybrid
of two CP(N) models coupled with each other in a dual symmetric fashion, and it
exhibits the gauge symmetry enhancement and radiative induction of the finite
off-diagonal gauge boson mass as in the 1+1 dimensional case. We solve the mass
gap equations and study the fixed point structure in the large-N limit. We find
an interacting ultraviolet fixed point which is in contrast with the 1+1
dimensional case. We also compute the large-N effective gauge action
explicitly.Comment: 26 pags, latex, 5 .eps figures, typos corrected. To appear in J.
Phys.
Gratings with an aperiodic basis: single-mode emission in multi-wavelength lasers
We propose a new class of gratings having multiple spatial frequencies. Their design relies on the use of small aperiodic grating sequences as unit cells whose repetition forms a superlattice. The superlattice provides well-defined Fourier components, while the choice of the unit cell structure enables the selection, modulation or suppression of certain Fourier components. Using these gratings to provide distributed feedback in mid-infrared quantum cascade lasers, we demonstrate simultaneous lasing on multiple well-defined and isolated longitudinal modes, each one having a sidemode suppression ratio of about 20 dB.United States. Air Force Office of Scientific Research (MURI 67N-1069926)Harvard University (Nanoscale Systems and Engineering Center)United States. Air Force (‘Deterministic Aperiodic Structures for Onchip Nanophotonic and Nanoplasmonic Device Applications’ under award no. FA9550-10-1- 0019)National Science Foundation (U.S.) (NSF CAREER Award ECCS-0846651)Georgia Institute of Technology (Steve W. Chaddick Endowed Chair of OptoElectronics
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