Differences In Relative Intensities Research Articles

In vivo assessment of bladder cancer with diffuse reflectance and fluorescence spectroscopy: A comparative study.

The aim of this work is to assess the performance of multimodal spectroscopic approach combined with single core optical fiber for detection of bladder cancer during surgery in vivo. Multimodal approach combines diffuse reflectance spectroscopy (DRS), fluorescence spectroscopy in the visible (405 nm excitation) and near-infrared (NIR) (690 nm excitation) ranges, and high-wavenumber Raman spectroscopy. All four spectroscopic methods were combined in a single setup. For 21 patients with suspected bladder cancer or during control cystoscopy optical spectra of bladder cancer, healthy bladder wall tissue and/or scars were measured. Classification of cancerous and healthy bladder tissue was performed using machine learning methods. Statistically significant differences in relative total haemoglobin content, oxygenation, scattering, and visible fluorescence intensity were found between tumor and normal tissues. The combination of DRS and visible fluorescence spectroscopy allowed detecting cancerous tissue with sensitivity and specificity of 78% and 91%, respectively. The addition of features extracted from NIR fluorescence and Raman spectra did not improve the quality of classification. This study demonstrates that multimodal spectroscopic approach allows increasing sensitivity and specificity of bladder cancer detection in vivo. The developed approach does not require special probes and can be used with single-core optical fibers applied for laser surgery.

Reducing Quantitative Uncertainty Caused by Data Processing in Untargeted Metabolomics.

Processing liquid chromatography-mass spectrometry-based metabolomics data using computational programs often introduces additional quantitative uncertainty, termed computational variation in a previous work. This work develops a computational solution to automatically recognize metabolic features with computational variation in a metabolomics data set. This tool, AVIR (short for "Accurate eValuation of alIgnment and integRation"), is a support vector machine-based machine learning strategy (https://github.com/HuanLab/AVIR). The rationale is that metabolic features with computational variation have a poor correlation between chromatographic peak area and peak height-based quantifications across the samples in a study. AVIR was trained on a set of 696 manually curated metabolic features and achieved an accuracy of 94% in a 10-fold cross-validation. When tested on various external data sets from public metabolomics repositories, AVIR demonstrated an accuracy range of 84%-97%. Finally, tested on a large-scale metabolomics study, AVIR clearly indicated features with computational variation and thus guided us to manually correct them. Our results show that 75.3% of the samples with computational variation had a relative intensity difference of over 20% after correction. This demonstrates the critical role of AVIR in reducing computational variation to improve quantitative certainty in untargeted metabolomics analysis.

Sexual competition and light regimes interactively affect dimorphism and competitiveness of opposite sexes in Populus yunnanensis

Light, as the most important energy and environmental signal, exerts crucial impacts on plant-plant interactions and the composition of plant communities. However, little attention has been paid to understanding how females and males respond to sexual competition under different light conditions. In this study, we investigated morphological and physiological parameters between two sexes of Populus yunnanensis under intra- and intersexual competition in two light regimes, i.e., full light and shading conditions (equal to 55% full light). Under full-light conditions, males grown under intersexual competition exhibited greater above-ground biomass accumulation, specific leaf area (SLA), root-to-shoot ratio (R/S), non-structural carbohydrate (NSC) utilization efficiency, and a higher ability to maintain the balance of nitrogen (N) and phosphorus (P) content compared to females. These eco-physiological responses confer males with a competitive advantage over females under sufficient light conditions. In contrast, there were no significant sex-specific differences in biomass accumulation and relative competitive intensity (RCI) values under shade treatment. Under shading, the opposite sexes of P. yunnanensis exhibited mutual suppression of each other to varying degrees, showing similar competitive potential. These results demonstrate that the performance of plants in terms of morphology and physiology is strongly affected by patterns of sexual competition and light regimes. The asymmetry in sexual competition might be a crucial factor influencing the biased sex ratio of P. yunnanensis in natural habitats.

Three-dimensional High-Resolution Dark-Blood Late Gadolinium Enhancement Imaging for Improved Atrial Scar Evaluation.

Background Radiofrequency ablation (RFA) is a widely used treatment for atrial fibrillation, reducing the risk of cardiac arrhythmia. Detailed visualization and quantification of atrial scarring has the potential to improve preprocedural decision-making and postprocedural prognosis. Conventional bright-blood late gadolinium enhancement (LGE) MRI can help detect atrial scars; however, its suboptimal myocardium to blood contrast inhibits accurate scar estimation. Purpose To develop and test a free-breathing LGE cardiac MRI approach that simultaneously provides high-spatial-resolution dark-blood and bright-blood images for improved atrial scar detection and quantification. Materials and Methods A free-breathing, independent navigator-gated, dark-blood phase-sensitive inversion recovery (PSIR) sequence with whole-heart coverage was developed. Two coregistered high-spatial-resolution (1.25 × 1.25 × 3 mm3) three-dimensional (3D) volumes were acquired in an interleaved manner. The first volume combined inversion recovery and T2 preparation to achieve dark-blood imaging. The second volume functioned as the reference for phase-sensitive reconstruction with built-in T2 preparation for improved bright-blood contrast. The proposed sequence was tested in prospectively enrolled participants who had undergone RFA for atrial fibrillation (mean time since RFA, 89 days ± 26 [SD]) from October 2019 to October 2021. Image contrast was compared with conventional 3D bright-blood PSIR images using the relative signal intensity difference. Furthermore, native scar area quantification obtained from both imaging approaches was compared with measurements obtained with electroanatomic mapping (EAM) as the reference standard. Results A total of 20 participants (mean age, 62 years ± 9; 16 male) who underwent RFA for atrial fibrillation were included. The proposed PSIR sequence successfully acquired 3D high-spatial-resolution volumes in all participants, with a mean scan time of 8.3 minutes ± 2.4. The developed PSIR sequence improved scar to blood contrast compared with conventional PSIR sequence (mean contrast, 0.60 arbitrary units [au] ± 0.18 vs 0.20 au ± 0.19, respectively; P < .01) and correlated with EAM regarding scar area quantification (r = 0.66 [P < .01] vs r = 0.13 [P = .63]). Conclusion In participants who had undergone RFA for atrial fibrillation, an independent navigator-gated dark-blood PSIR sequence produced high-spatial-resolution dark-blood and bright-blood images with improved image contrast and native scar quantification compared with conventional bright-blood images. © RSNA, 2023 Supplemental material is available for this article.

Spatial variations of Rn and CO2 emissions in the Wuzhong–Lingwu region, northwest China

Soil gas Rn and CO2 in surface rupture and deep-seated fault zones are important indicators for tectonic and seismic activities. The spatial distributions of Rn and CO2 concentrations and their relationships with earthquakes and stress state in the Wuzhong–Lingwu area of Ningxia, Northwest China, were investigated through field observations based on 76 measurement points, spatial interpolation and six crossing-fault profiles along Yellow River Fault zone (YRF). Observed results of the soil gas Rn and CO2 in different segments of Yellow River Fault zone illustrated that YRF has features of both strike-slip and certain normal fault characteristics. Moreover, the difference in seismic activity could also account for the differences in gas concentration and relative activity intensity (RAI) in the Yellow River Fault zone. Significant differences in the spatial distributions of Rn and CO2 were identified in gridded observation mode. By comparing these spatial distributions with the surface latent heat flux (SLHF), volumetric soil water layer (SWVL), and lithology, an anomalous high-Rn area was identified in the east and south Qingtongxia, and associated with Permian sandstone and mudstone in a piedmont setting. Away from a strong impact of irrigation in the Yinchuan Basin, CO2 anomalies were identified in the transition area between the Yinchuan Basin and the mountains and coincided with a dramatic negative variation of surface latent heat flux, which was considered to reflect humus accumulation, rich organic matter, and strong soil microorganism activity in loosely accumulated mountain alluvial deposits. After excluding gas anomalies related to shallow soils and surface geology, anomalies of Rn and CO2 in the west of Lingwu were consistent with the distribution of low seismic b-values and frequent seismic activity in plane and profile. According to similar studies in the north-south seismic belts, it is believed that high stress and strong seismic activity increased the permeability of rocks and boosted the gas emission in the west of Lingwu. Base on a crustal thickness variation belt, high-velocity bodies, and in this region, an higher seismic hazard was illustrated. This study offers new insight into combining geochemical characteristics of soil gas and seismological methods to estimate regional seismic hazards.

AI-3000K Infrared line list for hot CO2

AI-3000K is a semi-empirical IR line list constructed for hot CO2 spectra analysis and simulation up to 3000 – 4000 K. Compared to previously published Ames-1000K and UCL-4000, it represents a major upgrade, utilizing a new algorithm for optimization and including the latest improvements in potential energy surface (PES), dipole moment surface (DMS), and room temperature IR line list (Ames-2021 296K). To maximize the success of introducing experimental based accurate line positions, a new PES (X01d) was refined with respect to >800 selected CDSD2019 [Tashkun et al. JQSRT (2019) 228, 124] energy levels in the range of 0 – 24,000 cm−1, with σrms = 0.5 – 0.7 cm−1. Most differences between the X01d PES based levels and CDSD2019 energies are within ± 2 cm−1. A new DMS is fitted from extrapolated CCSD(T)/aug-cc-pV(T,Q,5)Z dipole calculations, with σrms = 5.1 × 10−6 au for 11,155 geometries up to 40,000 cm−1, denoted Ames-2021–40K. Compared to the best available Ames-2021 DMS and room temperature IR line list [Huang et al J. Phys. Chem. A (2022) 126, 5940], the relative intensity differences are expected to be ∼ 1 ‰. The line position accuracy of ''X01d + Ames-2021–40K'' IR line list is significantly improved by adopting CDSD2019 energy levels up to 24,000 cm−1 (J ≤ 150). The Einstein A21 coefficients for E' < 15,000 cm−1 transitions are replaced by more accurate values from the Ames-2021 296K IR line list. In short, the AI-3000K is the X01d PES and Ames-2021–40K DMS based line list enhanced with the A21 of Ames-2021 296K line list and CDSD energy levels. It provides continuous coverage from 0 to 20,000 cm−1 for the four most abundant isotopologues: 12C16O2 (626), 13C16O2 (636), 16O12C18O (628), and 16O12C17O (627). The impacts of isotopologue and E'/E'' cutoffs have been examined. Intensity convergence (not accuracy) of AI-3000K line list is quantitatively estimated in 1 cm−1 bins. It is better than 99% in the whole range of 0 – 20,000 (or 10,000) cm−1 at 1000 K (or 2000 K), or better than 90% in the whole range of 0 – 15,000 (or 9000) cm−1 at 2000 K (or 3000 K), respectively. Convergence beyond 3000 K will require a new PES and DMS for E' > 40,000 cm−1. The AI-3000K and HITEMP based IR simulations are compared to high resolution shock tube experiments for CO2-Ar mixture up to 2000 K. With line position accuracy comparable to that of HITEMP, AI-3000K IR line list yields better agreements at more frequencies. Potential sources of discrepancies with experiment are discussed.

Data evaluation strategy for identification of key molecular formulas in dissolved organic matter as proxies for biogeochemical reactivity based on abundance differences from ultrahigh resolution mass spectrometry

The molecular composition of dissolved organic matter (DOM) is of relevance for global carbon cycling and important for drinking water processing also. The detection of variation of DOM composition as function of time and space from a methodological viewpoint is essential to observe DOM processing and was addressed so far. High resolution concerning DOM quality was achieved with Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS).However almost none of the existing FTICR-MS data sets were evaluated addressing the fate of single mass features / molecular formulas (MFs) abundance during experiments. In contrast to former studies we analyze the function of MF abundance of time and space for such MFs which are present in all samples and which were formerly claimed as recalcitrant in not all but a great number of studies. For the first time the reactivity of MFs was directly compared by their abundance differences using a simple equation, the relative intensity difference (δRI). Search strategies to find out the maximum δRI values are introduced. The corresponding MFs will be regarded as key MFs (KEY-MFs). In order to test this new approach data from a recent photo degradation experiment were combined with monitoring surveys conducted in two drinking water reservoirs. The δRI values varied over one order of magnitude (more than five-fold). MFs like C9H12O6 and C10H14O6 revealed high biogeochemical reactivity as photo products. Some of the KEY-MFs were identical with MFs identified as disinfection byproducts precursors in recent studies. Other KEY-MFs were oxygen-rich and relatively unsaturated (poly-phenol-like) and hence relevant to flocculation procedures.

Enhanced intensity difference squeezing with a low gain off-resonant Four-Wave Mixing in potassium vapor

Although potassium stands out among alkalies by its smallest ground state hyperfine splitting, smaller than Doppler broadening, investigations of its four-wave mixing (FWM) quantum properties, like squeezing and entanglement, were neglected. Here we present measurements of quantum correlations in potassium vapor using far-detuned double Λ scheme for FWM. We obtained the relative intensity difference squeezing (IDS) of -6.1 dB, with the squeezing bandwidth between 0.9 to 4.5 MHz on the noise spectra. The squeezing maximum in potassium compares well with the best results obtained in Rb and Cs, and has larger value than previously reported IDS in potassium. This result agrees qualitatively well with the squeezing calculated using analytical expressions from the model of operators when with chosen parameters FWM generates both squeezing and probe at their maximums. The ultimate squeezing level in potassium, predicted by the model, when conjugate absorption in the cell and optical losses behind the cell are neglected, is −10.29 dB. This is among the largest predicting squeezing obtained by FWM in alkalies.

Low-frequency anharmonic couplings in crystalline bromoform: Theory.

Theoretical calculations of the low-frequency anharmonic couplings of the β-phase of crystalline bromoform are presented based on density functional theory quantum chemistry calculations. The electrical and mechanical anharmonicities between intra- and intermolecular modes are calculated, revealing that the electrical anharmonicity dominates the cross-peak intensities in the 2D Raman-THz response and crystalline, as well as liquid, bromoform. Furthermore, the experimentally observed difference in relative cross-peak intensities between the two intramolecular modes of bromoform and the intermolecular modes can be explained by the C3v-symmetry of bromoform in combination with orientational averaging. The good agreement with the experimental results provides further evidence for our interpretation that the 2D Raman-THz response of bromoform is, indeed, related to the anharmonic coupling between the intra- and intermolecular modes.

The effects of teak shades at different ages on early growth of 3 tuber species in Semin Village, Gunung Kidul

The government’s efforts in maintaining the food security includes developing alternative food sources, developing local food crops and improving the use of dry land for food crops cultivation. Planting tubers are common in private forest lands, such as in Semin Village, where arrowroot (Maranta arundinacea L.) can live under teak (Tectona grandis L.) stands. Based on this, a trial was conducted on planting three species of tubers, namely arrowroot/garut, canna/ganyong (Canna discolor Lindl.), and yam/gembili (Dioscorea esculenta (Lour.) Burk.) under teak stands. In mixed cropping patterns, there are limitations in obtaining light and nutrient sources for the plants underneath. Therefore, this study aimed to determine the morphological adaptation of three species of tubers, especially under the shade of teak, at different ages. The research design was completely randomized (CRD), while data analysis used two-way Anova. The results showed that the difference in relative light intensity (RLI) at eight weeks after planting had a significant effect on the height, the number of shoots or stems, and the number of leaves of the tested tubers. The size of the plant and the diameter of the stem showed the highest average under the shade of seven years teak stand, the contrary, the highest number of shoots or stems found in the open areas.

Light Field Reflection and Background Separation Network Based on Adaptive Focus Selection

Separating the background and the reflection layer is an ill-posed but meaningful task. Since the two layers often have different depths, Light Fields (LFs), which contain the depth information, show great potential to deal with this task. In this paper, we propose to fully exploit the difference between background and reflection layers from different kinds of images in LFs. Specifically, we fuse the complementary features from sub-aperture images, in which the overlaps of the two layers vary a lot. Then we propose the adaptive focus selection strategy and use the dynamic filter to select the appropriate focus. The refocused image is then obtained from the focal stack images, where the clearness of the two layers is different. Finally, the clean images are restored using a dual attention reconstruction module. Our model is the first one that successfully addresses the LF reflection separation task with an end-to-end deep neural network. The experiments show that the background and reflection layers are well separated, regardless of the relative intensity difference between the two layers on both synthetic and real-world datasets. The quantitative and qualitative comparison results show that our method achieves better performance than other state-of-the-art methods.

Technology catch‐up in agriculture among advanced economies

AbstractWe examine whether countries with low initial levels of agricultural total factor productivity (TFP) tend to ‘catch up’ with the technology leaders. We first compare relative levels of agricultural TFP, capital services and labour input levels in agriculture for 17 OECD countries between 1973 and 2011. Then we apply (conditional) convergence analysis to the panel data to examine the speed of convergence and test whether the convergence is transitory or permanent by analysing TFP changes over the business cycle. Capital intensities, quality improvement of capital, factors such as human capital spillovers, and certain agricultural policies are conditioning variables. We examine how differences in relative capital intensities affect agricultural productivity convergence over the business cycle. We find evidence that the speed of convergence increases during periods of contraction in economic activity.

Versatile Molecular Vibrations of Soliton Pairs in an Ultrafast Fiber Laser

Time-stretched spectroscopy based real-time measurement serves as an efficient access to the frontier research on the internal motions of soliton molecules, akin to matter molecules. A considerable question is raised of how far the light-matter analogy would reach. Here, we unveil this analogy from the aspect of molecular vibration, highlighting the versatile internal motions within soliton molecules in a near-zero-dispersion fiber oscillator. Assisted with real-time spectral interferometry, molecular vibration based composite internal motions are resolved towards extended degrees of freedom of dynamical soliton molecules. The relative intensity difference and the total energy fluctuation of the soliton pairs are presented to unveil the intrinsic mechanisms of internal motions. All these findings enrich the knowledge towards versatile internal motions of dual-pulse structures, further promoting the research on the analogy between optical soliton molecules and matter molecules.

Broadband coherent perfect absorption employing an inverse-designed metasurface via genetic algorithm.

Coherent perfect absorption (CPA) possesses the unique characteristics of flexibly and actively molding the flow of light. However, restricted by the low design efficiency and limited geometry variety of metamaterial structures, the common CPA metamaterial absorbers based on artificial design show poor performance in bandwidth operation. Here, we proposed a tungsten-based metamaterial absorber to achieve broadband CPA via employing genetic algorithm inverse design. Under the irradiation of two coherent beams, the high coherent absorption (>90%) can be achieved within a wide range from 1.32 to 3.28 µm. By simply adjusting the relative intensity or phase difference of the two coherent beams, the absorption intensity can be continuously modulated to realize the transition between coherent perfect absorption and coherent perfect transparency. Moreover, the coherent absorption maintains greater than 90% over a broad range of incident angles for both TM and TE polarizations. The scattering matrix theorem is applied to explain the physical mechanism of CPA, and the analytical results exhibit good consistency with the numerical calculations. Such a tungsten-based CPA metamaterial absorber with broadband tunability and exceptional angular stability is expected to be utilized in optical signal processing chips, all-optical modulators, and optical switchers.

Invariant-Based World Models for Robust Robotic Systems Demonstrated on an Autonomous Football Table

This work explains the use of invariants in robotic perception and control skills. An “invariant” is a mathematical constraint that remains unchanged under a particular transformation in a system. This property makes robotic functionalities more robust against “disturbances” that cause these transformation. These invariants are stored in a world model (WM), which has a central role in the information architecture of the robot to share information between components. A “robotic” football table serves as an example to illustrate the effectiveness of invariants. Despite looking different, all standard football tables satisfy the same set of invariants; the common layout of the field, line markings and puppets, which are not identical but satisfy the same set of constraints, such as parallelism, partial ordering, and relative colour and intensity differences between objects. During initialization, the invariants are actively identified and saved to the world model. During game play this world model is used by the perception and action skills and is updated when necessary. This work shows how the use of invariants creates robustness against variation in placement of the perception system and against variation in table dimensions and colours. When the camera is misaligned or moved mid-play, the world model is updated to ensure a smooth continuation of the game. The approach is tested on three standard football tables, with different dimensions and colours, showing that the approach is robust on standard tables that adhere to the invariants.

High-accuracy acoustic sediment classification using sub-bottom profile data

Sub-bottom sediment classifications have been widely used in marine science and engineering to obtain high-resolution information on types of sediments; however, these are often plagued by inaccuracies. Classification difficulties arise from the inability to effectively filter multiple reflections, extract representative lithology characteristic parameters, identify sub-bottom layer interfaces, extract image samples, control sample quality, optimise characteristic parameters, etc. To generate a highly accurate sub-bottom profile sediment map, a five-step classification method that considers two key lithology characteristic parameters of sub-bottom profile acoustic data was proposed. First, multiple reflections were filtered from the sea surface and sub-bottom layer interfaces of the primary signal. Second, two key characteristic parameters (relative backscattering intensity difference and attenuation compensation residual) were calculated. These reflect the relative differences in backscattering intensity and the attenuation compensation between adjacent interfaces based on the sound intensity attenuation model of a sub-bottom profile. Third, a combined method based on the sediment quality factor and peak trough of the echo signal loss level curve was employed to identify the actual interfaces between layers. An additional technique was proposed to determine the image sample width and preferred characteristic parameters. The resulting high-quality image samples and preferred characteristic parameters not only resulted in a faster convergence rate and increased ability of self-aggregation and identification, but also ensured that the training results met the convergence accuracy requirement. Ultimately, the preferred image samples were trained to classify the overall sub-bottom map of a selected test area of approximately 36 km2 in Bahai Bay, China. Compared with traditional methods, a considerably higher sediment identification accuracy was obtained. The experimental results indicate that the contribution rate of the two key lithology characteristic parameters was 65.49% according to principal component analysis, and the internal and external compatibilities were 97.98% and 84.76% for the training image samples, respectively. The total identification accuracy for the sub-bottom profile map was 98.2%. The two key characteristic parameters accurately captured the acoustic characteristics of sub-bottom sediments, significantly improving sediment classification. These results show that this method could be used to help refine the distributional estimates of submarine mineral resources.

Integrated plasmonic biosensor on a vertical cavity surface emitting laser platform.

Plasmonic devices can modulate light beyond the diffraction limit and thus have unique advantages in realizing an ultracompact feature size. However, in most cases, external light coupling systems are needed, resulting in a prohibitively bulky footprint. In this paper, we propose an integrated plasmonic biosensor on a vertical cavity surface emitting laser (VCSEL) platform. The plasmonic resonant wavelength of the nanohole array was designed to match (detune) with the emission peak wavelength of the VCSEL before (after) binding the molecules, thus the refractive index that represents the concentration of the molecule could be measured by monitoring the light output intensity. It shows that high contrast with relative intensity difference of 98.8% can be achieved for molecular detection at conventional concentrations. The size of the device chip could be the same as a VCSEL chip with regular specification of hundreds of micrometers in length and width. These results suggest that the proposed integrated sensor device offers great potential in realistic applications.

The missing 'link'? β-Catenin's role in skeletal muscle glucose uptake during exercise and contraction.

The missing 'link'? β-Catenin's role in skeletal muscle glucose uptake during exercise and contraction.

Acoustic differences between Chilean and Salvadoran Spanish /s/.

This paper examines seven acoustic properties of /s/ in Chilean Spanish (CS) and Salvadoran Spanish (ES). Acoustic measurements from 36 speakers, balanced for gender and dialect, reveal several cross-dialectal differences: CS /s/ was significantly longer than ES /s/ in coda position and had a higher spectral center of gravity. Two findings were mitigated by gender: women in both dialects were more likely to voice /s/, but the magnitude of the difference in voicing between male and female speakers was greater in CS. There were no differences in relative intensity in CS, while in ES, /s/ used by males has significantly lower relative intensity than /s/ used by females. No dialect differences were found for variance, kurtosis, or skewness. While both CS and ES are frequently collocated under the umbrella of "/s/ weakening dialects," our results show that tokens of non-deleted /s/ are acoustically distinct. These findings suggest that shorter duration and lower spectral energy in ES could be the result of a looser or backer constriction of /s/ and may have implications for work examining cross-dialectal differences in /s/ lenition at the phonetics/phonology interface.

Atypical Green Luminescence from Raw Cassia Siamea Extract: A Comparison with Red Emitting Tinospora Cordifolia.

Optical and electrochemical properties from Cassia and Giloy leaves' raw extract have been studied, and they show similar properties as UV absorber but different emission properties, under UV excitation, even though they appear the same in natural light. Giloy and Cassia extracts show red and green luminescence, respectively, under UV excitation. Like the appearance, their redox properties are also similar, which shows that both can act as antioxidants. Raman spectroscopy and excitation wavelength dependent photoluminescence data have been compared. The difference in relative emission intensities have been explained based on the presence of corresponding color centers in different ratios in the two leaves.