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Slow light : invisibility, teleportation and other mysteries of light
\"Slow Light is a popular treatment of today's astonishing breakthroughs in the science of light. Even though we don't understand light's quantum mysteries, we can slow it to a stop and speed it up beyond its Einsteinian speed limit, 186,000 miles/sec; use it for quantum telecommunications; teleport it; manipulate it to create invisibility; and perhaps generate hydrogen fusion power with it. All this is lucidly presented for non-scientists who wonder about teleportation, Harry Potter invisibility cloaks, and other fantastic outcomes. Slow Light shows how the real science and the fantasy inspire each other, and projects light's incredible future.\" -- Back Cover.
Book
Beam Propagation Method for Design of Optical Waveguide Devices
The basic of the BPM technique in the frequency domain relies on treating the slowly varying envelope of the monochromatic electromagnetic field under paraxial propagation, thus allowing efficient numerical computation in terms of speed and allocated memory. In addition, the BPM based on finite differences is an easy way to implement robust and efficient computer codes. This book presents several approaches for treating the light: wide-angle, scalar approach, semivectorial treatment, and full vectorial treatment of the electromagnetic fields. Also, special topics in BPM cover the simulation of light propagation in anisotropic media, non-linear materials, electro-optic materials, and media with gain/losses, and describe how BPM can deal with strong index discontinuities or waveguide gratings, by introducing the bidirectional-BPM. BPM in the time domain is also described, and the book includes the powerful technique of finite difference time domain method, which fills the gap when the standard BPM is no longer applicable. Once the description of these numerical techniques have been detailed, the last chapter includes examples of passive, active and functional integrated photonic devices, such as waveguide reflectors, demultiplexers, polarization converters, electro-optic modulators, lasers or frequency converters. The book will help readers to understand several BPM approaches, to build their own codes, or to properly use the existing commercial software based on these numerical techniques.
eBook
No impact of polymorphism in the phosphodiesterase 5A gene in Cavalier King Charles Spaniels on pimobendan‐induced inhibition of platelet aggregation response
Background A variant in the canine phosphodiesterase (PDE) 5A gene (PDE5A:E90K) is associated with decreased concentrations of circulating cyclic guanosine monophosphate (cGMP) and response to PDE5 inhibitor treatment. Pimobendan is a PDE inhibitor recommended for medical treatment of certain stages of myxomatous mitral valve disease (MMVD) in dogs. Hypothesis PDE5A:E90K polymorphism attenuates the inhibitory effect of pimobendan on in vitro platelet aggregation and increases basal platelet aggregation in Cavalier King Charles Spaniels (CKCS). Selected clinical variables (MMVD severity, sex, age, hematocrit, platelet count in platelet‐rich plasma [PRP], and echocardiographic left ventricular fractional shortening [LV FS]) will not show an association with results. Animals Fifty‐two privately owned CKCS with no or preclinical MMVD. Methods Using blood samples, we prospectively assessed PDE5A genotype using Sanger sequencing and adenosine diphosphate‐induced platelet aggregation response (area under the curve [AUC], maximal aggregation [MaxA], and velocity [Vel]) with and without pimobendan using light transmission aggregometry. Dogs also underwent echocardiography. Results Pimobendan inhibited platelet function as measured by AUC, MaxA, and Vel at a concentration of 10 μM (P < .0001) and Vel at 0.03 μM (P < .001). PDE5A:E90K polymorphism did not influence the inhibitory effect of pimobendan or basal platelet aggregation response. Conclusions and Clinical Importance The PDE5A:E90K polymorphism did not influence in vitro basal platelet aggregation response or the inhibitory effect of pimobendan on platelet aggregation in CKCS. Dogs with the PDE5A:E90K polymorphism did not appear to have altered platelet function or response to pimobendan treatment.
Journal Article
Assessment of the efficacy of various mulch materials on improving the growth and yield of ginger (Zingiber officinale) under bamboo-based agroforestry system in NW-Himalaya
Agroforestry as a smart agriculture practice has started to get global attention nowadays. The present investigation is based on bamboo-ginger intercropping research carried out on a field near Solan, Himachal Pradesh, India. Randomized Complete Block Design experiment was employed with two bamboo species (Dendrocalamus asper and Bambusa balcooa) and a sole cropping system (open field condition) intercropped with ginger crop (Zingiber officinale) treated with mulches;T1:Toona ciliata + Farmyard manure (FYM) + Recommended dose of fertilizers (RDF); T2: Artemisia vulgaris + FYM + RDF; T3:Ulmus villosa + FYM + RDF;T4: Celtis australis + FYM + RDF; T5: Pinus roxburghii + FYM + RDF; T6:FYM + RDF; T7:Control (no application). Intercropping with bamboo species was observed to enhance ginger yield and oleoresin contents by 10.5–15.6 and 14.45–28.61 percent over sole cropping, respectively. The gingers crop traits such as rhizome sprouting (%), number of rhizomes per plant, rhizome fresh weight (g), yield (qha−1), and oleoresin content (%) exhibited maximum values with T1 treatment. Intercropping with D. asper showed better results for ginger yield traits than B. balcooa and/or sole cropping. At the termination of the experiment, organic carbon (OC) and available N showed maximum values in T3 (U. villosa + FYM + RDF). However, the maximum available P was recorded in T1 (T. ciliate + FYM + RDF), while the available K was found maximum in T4 (C. australis + FYM + RDF). Furthermore, the soil moisture content (%) under the canopies of bamboo species was higher than that under sole cropping. The Light Transmission Ratio (LTR %) was reduced by about 40 per cent beneath the bamboo canopies. The present study observed that ginger performs better in a bamboo-based agroforestry system (AFS) than under sole cropping system and the application of green mulches have demonstrated efficacy in enhancing ginger yield and quality, soil health, soil moisture and weed suppression.
Journal Article
Evaluation of clopidogrel response in healthy cats using a novel viscoelastic test and thromboelastography
Cats with cardiomyopathy face an increased risk of arterial thromboembolism (ATE). Although clopidogrel is frequently utilized to mitigate this risk, feline responses to this therapy exhibit variability. This study evaluated 2 viscoelastic devices, thromboelastography (TEG) and Viscoelastic Coagulation Monitor (VCM), for monitoring clopidogrel in cats in comparison to light transmission aggregometry (LTA).
Twenty-eight healthy cats received clopidogrel for 7 days. Blood was collected at baseline and after treatment for analysis by TEG, VCM, and LTA.
On LTA, maximum amplitude, slope, and area under the curve (AUC) significantly decreased after treatment (
< 0.0001). On VCM, maximum clot firmness (MCF) significantly increased after treatment (
= 0.002). On TEG, R-time significantly prolonged (
= 0.024), while K and alpha angle significantly changed (
= 0.0002 and
= 0.0014, respectively). There was a moderate negative correlation between TEG R-time and LTA AUC (
= -0.39,
= 0.042). Eight cats were identified as non-responders to clopidogrel. Of the 8 non-responders, 6 (75%) had shortened R time after treatment. VCM appeared to be less discriminatory in identifying non-responders.
LTA remained the gold standard of monitoring clopidogrel treatment in cats. Unexpected changes on VCM and TEG were likely related to high interindividual and assay variability and increased sensitivity of feline platelets. R-time on TEG may have potential utility for point-of-care monitoring of clopidogrel response in cats.
Journal Article
The Role of Diamonds Dispersed in Ferronematic Liquid Crystals on Structural Properties
A study of the role of diamond nanoparticles on 5CB liquid crystal composites with Fe3O4 nanoparticles is presented. Composite ferronematic systems based on the nematic liquid crystal 5CB doped with Fe3O4 magnetic nanoparticles and additionally bound to diamond nanoparticles (DNPs), of a volume concentration of 3.2 mg/mL, 1.6 mg/mL and 0.32 mg/mL, were investigated using both magneto-optical effect and surface acoustic waves (SAWs) to study the role of diamond nanoparticles on the structural properties of ferronematic liquid crystals. The responses of light transmission and SAW attenuation to an external magnetic field were investigated experimentally under a linearly increasing and decreasing magnetic field, respectively. Investigations of the phase transition temperature shift of individual composites were also performed. The experimental results highlighted a decrease in the threshold field in the ferronematic LC composites compared to the pure 5CB as well as its further decrease after mixing Fe3O4 with diamond powder. Concerning the transition temperature, its increase with an increase in the volume fraction of both kinds of nanoparticles was registered. The role of diamond nanoparticles in the structural changes and the large residual light transition and/or attenuation (memory effect) were also observed. The presented results confirmed the potential of diamond nanoparticles in nematic composites to modify their properties which could lead to final applications.
Journal Article
Assessing the influence of infiltration on the migration of light non-aqueous phase liquid in double-porosity soil media using a light transmission visualization method
The influence of infiltration on the migration of a light non-aqueous phase liquid (LNAPL) in double-porosity soil using the light transmission visualization (LTV) technique is investigated. Two LNAPL volumes (low and high volumes) were exposed to two rainfall intensities (light and heavy infiltration). For comparison purposes, the experiments were also repeated by compacting the flow chamber with silica sand only to represent the single-porosity medium and to investigate the influence of double-porosity on LNAPL migration. High-resolution LTV images of the flow chamber during LNAPL injection and subsequent water infiltration events were collected. Results show that the LNAPL migration depth during injection and its migration velocity were both correlated to the LNAPL volume. Subsequent water infiltration events caused the LNAPL that was entrapped in the porous media to be pushed further downward in all the experiments. The LNAPL migration velocity was 1.1 and 1.6 cm/h for the low and high LNAPL spillage volumes for double-porosity experiments, respectively, a reduction rate of 64.7 and 70% compared to the LNAPL migration velocity during LNAPL injection, respectively. However, for single-porosity experiments, the LNAPL migration velocity was 0.7 and 1.2 cm/h for the low and high LNAPL volumes, respectively. Furthermore, it was observed that the capillary fringe level was depressed in the saturated zone due to the influence of both infiltration and LNAPL volume. This study demonstrates that the LTV technique is an accurate and cost-effective laboratory tool for the visualization of the time-dependent influence of infiltration on LNAPL migration in porous media.
Journal Article
Physiological and proteome studies of maize (Zea mays L.) in response to leaf removal under high plant density
Background
Under high plant density, intensifying competition among individual plants led to overconsumption of energy and nutrients and resulted in an almost dark condition in the lower strata of the canopy, which suppressed the photosynthetic potential of the shaded leaves. Leaf removal could help to ameliorate this problem and increase crop yields. To reveal the mechanism of leaf removal in maize, tandem mass tags label-based quantitative analysis coupled with liquid chromatography–tandem mass spectrometry were used to capture the differential protein expression profiles of maize subjected to the removal of the two uppermost leaves (S
2
), the four uppermost leaves (S
4
), and with no leaf removal as control (S
0
).
Results
Excising leaves strengthened the light transmission rate of the canopy and increased the content of malondialdehyde, whereas decreased the activities of superoxide dismutase and peroxidase. Two leaves removal increased the photosynthetic capacity of ear leaves and the grain yield significantly, whereas S
4
decreased the yield markedly. Besides, 239 up-accumulated proteins and 99 down-accumulated proteins were identified between S
2
and S
0
, which were strongly enriched into 30 and 23 functional groups; 71 increased proteins and 42 decreased proteins were identified between S
4
and S
0
, which were strongly enriched into 22 and 23 functional groups, for increased and decreased proteins, respectively.
Conclusions
Different defoliation levels had contrastive effects on maize. The canopy light transmission rate was strengthened and proteins related to photosynthetic electron-transfer reaction were up-regulated significantly for treatment S
2
, which improved the leaf photosynthetic capacity, and obtained a higher grain yield consequently. In contrast, S
4
decreased the grain yield and increased the expressions of proteins and genes associated with fatty acid metabolism. Besides, both S
2
and S
4
exaggerated the defensive response of maize in physiological and proteomic level. Although further studies are required, the results in our study provide new insights to the further improvement in maize grain yield by leaf removal.
Journal Article
Structure and properties of polyvinyl alcohol (PVA)/Al2O3 antifogging coating with self-healing performance
Condensation of fog droplets on polyethylene (PE) films significantly impairs light transmission of the film. This study introduces a PVA/Al
2
O
3
antifogging coating, applied to PE films using polyvinyl alcohol (PVA) and nanoaluminum sol. The resultant coatings exhibit superior wettability and an extended antifogging lifespan. Specifically, the coating maintains a low contact angle of 21.1° and demonstrates an antifogging duration of up to 60 days in a 60°C hot fog environment. Notably, light transmission at 500 nm wavelength is enhanced by 3.5% with the PVA/Al
2
O
3
coating compared to the uncoated PE film, thereby facilitating plant photosynthesis. Moreover, the coating displays a remarkable self-healing capacity upon external damage, significantly prolonging the antifogging film’s durability.
Journal Article
Characterization of Capillary Pressure–Saturation Relationships for Double-Porosity Medium Using Light Transmission Visualization Technique
Capillary pressure saturation (
P
c
–
S
w
) relationship plays a central role in the description of fluid flow in porous media. In this research, the light transmission visualization (LTV) technique was applied to characterize the
P
c
–
S
w
relationship in a double-porosity medium. Four experiments were conducted in two-dimensional (2-D) flow chambers packed with a double-porosity medium composed of a mixture of silica sand and sintered kaolin clay spheres. In each experiment, a different volumetric fraction of macropores and micropores was used. The experiment was also repeated by compacting the flow chamber with silica sand only to represent single-porosity medium. Variable saturations of water across the height of the system were applied by controlling the capillary pressure. Images of the 2-D model were collected using a digital camera and analyzed pixel by pixel to determine water saturation in the double-porosity medium. Results from the LTV technique showed that the
P
c
–
S
w
relationships for all experiments in double-porosity soil medium were similar in shape but varied depending on the porous media composition. Comparison with the pressure cell test results showed that the
P
c
–
S
w
curves for all experiments consistent comparable to those obtained by the LTV technique. The
P
c
–
S
w
curves were also fit to van Genuchten model for comparison and validation. For double-porosity media, the best-fit parameters were consistent with published data for sandy clay. Moreover, little variability was observed in the best-fit
α
and
n
values for the different double porosity. Overall, this study proves that the LTV technique is a noninvasive laboratory tool that can provide high-resolution spatial data for water saturation distribution in different types of porous media and is capable of producing highly resolved
P
c
–
S
w
relationships.
Journal Article