Portion Of Light Research Articles

Searching for the mHz variability in the TESS observations of nova-like cataclysmic variables

We investigated the fast optical variability of selected nova-like cataclysmic variables observed by the satellite. We searched for break frequencies b $) in the corresponding power density spectra (PDS). The goal is to study whether these systems in an almost permanent high optical state exhibit preferred $f_ b $ around 1\,mHz. We selected non-interrupted light curve portions with durations of 5 and 10 days. We divided these portions into ten equally long light curve subsamples and calculated mean PDS. We searched for $f_ b $ in the frequency interval from log($f$/Hz) = -3.5 to -2.4. We defined as a positive detection when the $f_ b $ was present in at least 50<!PCT!> of the light curve portions with a predefined minimum number of detections. We have measured $f_ b $ in 15 nova-like systems and confirmed that the value of this frequency is clustered around 1\,mHz with a maximum of the distribution between log($f$/Hz) = -2.95 and -2.84. The confidence that this maximum is not a random feature of a uniform distribution is at least 96<!PCT!>. This is a considerable improvement on the previous value of 69<!PCT!>. We discuss the origin of these b $ in the context of the sandwich model in which a central hot X-ray corona surrounds a central optically thick disc. This scenario could be supported by a correlation between the white dwarf mass and $f_ b $; the larger the mass, the lower the frequency. We see such a tendency in the measured data; however, the data are too scattered and based on a low number of measurements. Finally, it appears that systems with detected $f_ b $ have a lower inclination than 60-75$^ circ $. In higher-inclination binaries, the central disc is not seen and the PDS is dominated by red noise. This also supports the inner disc regions as being the source of the observed $f_ b

Pulsed Light Technology: Is it Sustainable?

Abstract Pulsed light is a non-thermal method that was initially researched for microbial inactivation using high-power, broad-spectrum light pulses, with the UV-C light portion being the most lethal. This method was introduced to the Western hemisphere with the Hiramoto US patent in 1984 and was developed by PurePulse Technologies. It obtained the FDA approval for food use in 1996 and has been under continuous study and testing by academic institutions since 1998. It is linked to sustainable development goals 2, 3, 6, and 12, but its relation to goal 13 is particularly important, although hindered by lack of data. While numerous applications beyond microbial inactivation have been developed, only two are currently used industrially, namely, the decontamination of food contact surfaces for packaging and the enhancement of vitamin D concentration in edible fungi. Other potential applications include enzyme inactivation, phytochemical synthesis, water pollutant degradation, protein allergen inactivation, mycotoxin inactivation, modification of functional properties of proteins, and starch modification. The main advantage of pulsed light is its rapid effects although it is limited to surfaces and transparent liquids. Further refinement of dosimetry should facilitate the easier scaling up of laboratory results to more industrial applications. Information © The Author 2024

Effect of sex and milk replacer with or without supplemental carnitine and arginine on growth characteristics, carcass, and meat quality of artificially reared low-birth weight pigs.

This study compared milk replacer either remaining unsupplemented (CON) or supplemented with 0.5g L-carnitine plus 16.7g L-arginine/kg (CarArg) and fed to 48 low-birth weight (L-BtW) artificially reared piglets (24 per group) from days 7 to 28 of age. Eight farrowing series were needed to complete the study. On day 28, the lightest piglets were slaughtered, and the heaviest pigs were weaned. The heaviest pigs were weaned on day 28 and offered free access to a starter (weaning to 25kg body weight [BW]), grower (25 to 60kg BW), and finisher diet (60 to 96kg BW on day 170 of age). After euthanization on days 28 and 170, blood was sampled for assessment of serum metabolite and hormone concentrations, and the semitendinosus muscle (STM) was weighed, and later subjected to enzyme activity analysis and assessment of myofiber characteristics. In the 170-d-old pigs carcass and meat quality traits were assessed. Growth data were analyzed accordingtoatwo-way analysis of variance (ANOVA), with dietary treatment and farrowing series as fixed effects, while remaining data were analyzed with dietary treatment, sex, their interaction, and farrowing series as main factors. Dietary treatments affected (P ≤ 0.049) muscle enzyme activity at both day 28, with greater citrate synthase (CS) and LDH activities and lower HAD:CS ratio in STM light portion, and lower LDH:CS ratio in STM dark portion, and 170 of age with lower HAD:CS ratio. In the starter period, CarArg pigs had greater average daily gain (P = 0.021) and average daily feed intake (P = 0.010). At slaughter, these pigs had lower (P = 0.013) glucose and greater (P = 0.022) urea serum concentrations. However, supplementing the milk replacer with carnitine and arginine had no long-term effects on growth performance, carcass composition, and meat quality of L-BtW pigs. In addition, muscle morphology and myofiber-related properties remained unaffected by the supplementation.

The effect of continuous long-term illumination with visible light in different spectral ranges on mammalian cells

One of the biggest challenges in tissue engineering and regenerative medicine is to ensure oxygen supply of cells in the (temporary) absence of vasculature. With the vision to exploit photosynthetic oxygen production by microalgae, co-cultivated in close vicinity to oxygen-consuming mammalian cells, we are searching for culture conditions that are compatible for both sides. Herein, we investigated the impact of long-term illumination on mammalian cells which is essential to enable photosynthesis by microalgae: four different cell types—primary human fibroblasts, dental pulp stem cells, and osteoblasts as well as the murine beta-cell line INS-1—were continuously exposed to warm white light, red or blue light over seven days. We observed that illumination with red light has no adverse effects on viability, metabolic activity and growth of the cells whereas exposure to white light has deleterious effects that can be attributed to its blue light portion. Quantification of intracellular glutathione did not reveal a clear correlation of this effect with an enhanced production of reactive oxygen species. Finally, our data indicate that the cytotoxic effect of short-wavelength light is predominantly a direct effect of cell illumination; photo-induced changes in the cell culture media play only a minor role.

Illuminating microflora: shedding light on the potential of blue light to modulate the cutaneous microbiome.

Cutaneous diseases (such as atopic dermatitis, acne, psoriasis, alopecia and chronic wounds) rank as the fourth most prevalent human disease, affecting nearly one-third of the world's population. Skin diseases contribute to significant non-fatal disability globally, impacting individuals, partners, and society at large. Recent evidence suggests that specific microbes colonising our skin and its appendages are often overrepresented in disease. Therefore, manipulating interactions of the microbiome in a non-invasive and safe way presents an attractive approach for management of skin and hair follicle conditions. Due to its proven anti-microbial and anti-inflammatory effects, blue light (380 - 495nm) has received considerable attention as a possible 'magic bullet' for management of skin dysbiosis. As humans, we have evolved under the influence of sun exposure, which comprise a significant portion of blue light. A growing body of evidence indicates that our resident skin microbiome possesses the ability to detect and respond to blue light through expression of chromophores. This can modulate physiological responses, ranging from cytotoxicity to proliferation. In this review we first present evidence of the diverse blue light-sensitive chromophores expressed by members of the skin microbiome. Subsequently, we discuss how blue light may impact the dialog between the host and its skin microbiome in prevalent skin and hair follicle conditions. Finally, we examine the constraints of this non-invasive treatment strategy and outline prospective avenues for further research. Collectively, these findings present a comprehensive body of evidence regarding the potential utility of blue light as a restorative tool for managing prevalent skin conditions. Furthermore, they underscore the critical unmet need for a whole systems approach to comprehend the ramifications of blue light on both host and microbial behaviour.

Organic Photoplethysmography Sensor Based on Directional Emission Microcavity Organic Light‐Emitting Device

AbstractWearable photoplethysmography (PPG) sensors provide real‐time monitoring of essential human health parameters by integrating a light source with a photodetector. However, they face a common challenge: the presence of a faint pulsating (AC) signal amidst a highly noisy and drifting non‐pulsatile background. This necessitates fine‐tuning how the light is spread out to make sure that a significant number of emitted photons carry vital physiological information and trigger the detector's photocurrent. An innovative organic PPG sensor with a microcavity organic light‐emitting diode (OLED) that emits light in a controlled direction, coupled with an annular organic photodetector (OPD) is demonstrated here. By adjusting the OLED's cavity lengths, the microcavity resonance peak is shifted, achieving angled directional emission. Placing the microcavity OLEDs at the center of the annular OPD enhances the portion of light that reflects from arterial vessels in the skin and tissues. This increases the AC signal for recording arterial vessel pulsations by 47.66%. This advancement simplifies sensor recognition and achieves an unprecedented low power consumption of only 9.96 µW for heart rate sensing, meeting essential recognition criteria.

A new type of core-shell nanowire array structured quantum dot-composite perovskite solar cell with near full-spectrum absorption

The core-shell structured nanowire array solar cell has a larger absorption area and enhanced light capturing capability, thus enabling more efficient absorption of solar energy. By using perovskite materials as the absorber material, it can effectively absorb ultraviolet light and a portion of visible light, but its absorption capacity for red light and infrared light is relatively weak. Quantum dots (QDs) can effectively extend the absorption range of the solar cell, particularly in the infrared regions. Therefore, in this work, QDs were combined with perovskite materials, and then an electron transport layer/quantum dot/perovskite/hole transport layer core-shell structure nanowire array solar cell was constructed. Compared to structures without QDs, the new structure has a broader absorption range, improved charge carrier transport, and enhanced photoconversion efficiency. This would provide a new structure for wide-spectrum absorbing solar cells.

Adolescent social isolation increases binge-like alcohol drinking in male but not female high-alcohol-preferring mice.

This study examined how adolescent social isolation affects adult binge-like alcohol drinking and stress-axis function, via basal levels of circulating corticosterone (CORT), in male and female mice with a genetic predisposition toward high alcohol preference (HAP). Male and female HAP2 mice were randomly assigned to a group-housed or social isolation (ISO) group. Social isolation began at postnatal Days 40-42 and lasted for 21days prior to assessment of binge-like alcohol drinking using a 4-day drinking-in-the-dark (DID) procedure. Blood samples to assess basal CORT were taken 6days after social isolation ended and 24h before DID started, and again 60h after DID ended, during the light portion of the light cycle. Adolescent social isolation increased adult binge-like alcohol drinking in male but not female mice. All groups showed significantly lower CORT after DID compared to before DID. Pearson bivariate correlation coefficients between the first 2h of grams-per-kilogram alcohol intake on Day 4 and CORT levels indicated a significant positive correlation in ISO males only after DID and negative correlations in ISO females before and after DID. These findings demonstrate that adolescent social isolation increased binge-like alcohol drinking in male but not female adult HAP2 mice. Stress-axis adaptations in male HAP2 mice may be associated with the social-isolation-induced increase in binge-like alcohol drinking.

Mechanical and energy absorption properties of multilayered ultra-light sandwich panels produced by 3D-printing and electroforming

This investigation aims to assess the mechanical and energy absorption properties of the light sandwich panel portions made of open-cell polymer and metal/polymer foam cores. These multi-layered sandwich panels were produced by additive manufacturing of polymeric resin and electrodeposition of three layers of metals, Ni/Ni−Cu/Ni, with 4,5, and 6 pores per inch (PPI). The yield strength, energy absorption density, complementary energy, and specific energy absorption (SEA)were measured during uniaxial compression deformation. The results indicate that compared with pure Ni and Cu sandwich panel portions with the same thickness, the abovementioned properties of the sandwich panels had a noteworthy improvement. Mechanical and energy absorption properties were improved by increasing the PPI and the presence of metallic layers. In a sandwich panel with 6 PPI, the yield strength (energy absorption density)wasimproved from 0.12 MPa (0.12 MJ/m3) for the polymeric sandwich panel to 1.83 MPa (0.67 MJ/m3)for the metallic sandwich panel. Investigations on normalized energies of these structures show a predictable behavior for these sandwich panels during plastic deformations. The results show that the multi metallic layers improved the mechanical behavior of these novel sandwich panels. Noticeable enhancement of the calculated properties of these advanced materials guarantees their unique application in variable industries.

Flexible top-illuminated organic photodetector using an ultrathin-metal-based transparent electrode

Top-illuminated structure facilitates the integration of organic photodetectors (OPDs) into high-resolution flexible wearable light detection systems by allowing the OPDs to be deposited on the bottom readout circuit. However, constructing this structure poses a challenge as it demands metallic electrodes with both high optical transparency and high electrical conductivity. But to achieve practical sheet resistances, most semitransparent metallic electrodes tend to reflect a large portion of incident light instead of allowing it to be absorbed by the photoactive layer of the OPDs. This, in turn, results in reduced photocurrent generation. To address this issue, a semiconducting germanium (Ge) film is introduced into a sliver (Ag) film, effectively reducing its reflectivity by lessening scattering. The Ge film also changes how the Ag film grows, further reducing its absorption by lowering the critical thickness needed for forming a continuous film. This approach yields a 10 nm metallic electrode with a transmittance of 70%, a reflectivity of 12%, and a sheet resistance of 35.5 Ω/□. Using this metallic electrode, flexible OPDs exhibit a high photo-to-dark current ratio of 2.9×104 and improved mechanical properties. This finding highlights the benefits of the top-illuminated structure, which effectively reduces losses caused by waveguided modes of the incident light.

Trismelasmos neirai sp. n. (Lepidoptera, Cossidae, Zeuzerinae) from Solomon Islands

The article describes Trismelasmos neirai Yakovlev & Hulsbosch sp. nov. distributed in Solomon Islands (Guadalcanal Island). The article has two illustrations. The new species is most close to T. vavilovi Yakovlev, 2022, from which is differs in a series of characters: the uniform coating of gray and light grey scales on the upper surface of the fore wing (in T. vavilovi, there is a light portion in the middle of the fore wing and a small light-brown portion on the fore wing basally); the smooth abdominal margin of the valve (in T. vavilovi, the abdominal margin of the valve has a deep notch on the border between the basal and medium thirds); the phallus, strongly curved along all its length (in T. vavilovi, the phallus is almost straight).

In Situ Surface Modification Enables High Stability and Optoelectrical Performance for a Self‐powered Photodetector

AbstractPerovskite single crystals (SCs) have gained significant interest in various applications owing to their superior optoelectrical and physical characteristics as compared to polycrystalline films. However, a considerable portion of incident light is typically reflected at the surface of perovskite SCs, leading to insufficient light absorption within the crystal bulk, ultimately resulting in reduced performance of SC‐based photodetectors. In the present work, an inverted pyramid‐shaped structure is in situ introduced on the surface of an MAPbBr3 SC during the crystal growth process, which can reduce light reflection in the surface region and enhance light absorption of the SC. Additionally, the hydrophobic small molecule copper (II) phthalocyanine (CuPc) is thermally evaporated onto the SC, forming a CuPc/MAPbBr3 heterojunction for the first time. The CuPc/pyramid‐shaped MAPbBr3 heterojunction‐based photodetector exhibits self‐powered characteristics and superior optoelectrical performance, achieving a photocurrent of greater than 10−5 A (10−7 A), a responsiveness of 257 mA W−1 (8.84 mA W−1), and a detection rate of 2.98 × 1012 Jones (1.02 × 1011 Jones) at −2 V (0 V) bias. Simultaneously, the device demonstrates excellent long‐term stability under high humidity conditions, retaining 90.5% of its initial photocurrent even after 60 days in a 60–80% humidity environment.

The Influence of LED Lights of Different Spectrum on the Development of <i>Lactuca sativa</i>

The effect of light-emitting diode (LED) lamps with 5 different spectra on L. sativa plants (variety ‘Aficion’) grown in protected soil conditions was studied. Warm white light (WW) was used as a control (the ratio of blue, green and red portions in the spectrum was 14% : 48% : 38%). The maximum values of leaf size and fresh weight of the aerial parts were found in the RGB group (blue-green-red ratio 32% : 19% : 49%), highest values of dry weight and ash content – in the FS group (blue-green-red ratio 27% : 11% : 62%). Stomatal size and density on the abaxial leaf’s side was the highest in SB plants (blue-green-red ratio 33% : 41% : 38%). This was the most effective combination of parameters in terms of leaf architectonics. An increase in the portion of red light in the spectrum with a decrease in the portion of green light had a positive effect on the development of L. sativa plants, while an increase in the portion of green light in the spectrum positively affected-the stomatal apparatus formation.

Machine Learning-Enabled Inverse Design of Radiative Cooling Film with On-Demand Transmissive Color

Passive radiative cooling is a cost-efficient and eco-friendly approach to cool terrestrial objects by dissipating heat to the outer space. Colored radiative cooling (CRC) has many advantages over conventional passive radiative cooling and has garnered growing interest recently. However, existing CRC films are normally opaque, where the incident sunlight is either reflected for rendering color or absorbed to generate waste heat. In this work, we design a transmissive CRC film that allows a specific portion of light to pass through and provides more vivid colors. Such a transmissive film achieves the coloration and cooling dual-function by stacking a solar transparent selective emitter on top of a nanocavity-based color filter. The top emitter is first designed by using a mixed-integer memetic algorithm, where the layer materials, their number sequence, and thicknesses are simultaneously optimized. The variability in both material composition and layer thickness enables the emitter with a near-ideal emissivity in the atmospheric windows for subambient cooling, and an ultrahigh transmissivity in the solar range for sunlight penetration. Then, the structures of bottom nanocavity are determined by using a tandem neural network for on-demand color generation. This machine learning-assisted inverse design approach provides real-time structure prediction for on-demand colors and offers great flexibility in balancing the cooling and coloring functionalities. The proposed methodology can have special significance in broadening the application of passive radiative coolers in energy-efficient buildings, power-generating windows, and sustainable greenhouses.

Quartz Vein Formation and Deformation during Porphyry Cu Deposit Formation: A Microstructural and Geochemical Analysis of the Butte, Montana, Ore Deposit

Abstract Hydrothermal quartz veins from the Butte deposit display euhedral and mottled cathodoluminescent (CL) textures that reflect the growth and deformation history of quartz crystals. A CL-euhedral texture consists of oscillatory dark-light zonations that record primary precipitation from an aqueous fluid. The origin of a CL-mottled texture, which consists of irregularly distributed dark and light portions, is less clear. Previous work showed that in some veins, CL-euhedral and CL-mottled crystals coexist, but the processes leading to their formation and coexistence were unknown. We find that CL-mottled crystals occur predominantly along the wall rock fracture surface and in vein centers and that CL-euhedral cockscomb quartz protrudes from the mottled layers along the wall rock. We infer that the mottled crystals formed by strain-induced recrystallization that was preferentially accommodated by the rheologically weaker layers of noncockscomb quartz because cockscomb crystals are in hard glide orientations relative to adjacent noncockscomb layers. During strain, crystals in noncockscomb layers that are not initially susceptible to slip can rotate in their deforming matrix until they deform plastically. Some of the CL-mottled crystals exhibit a relict CL-euhedral texture (“ghost bands”) whereby bright bands have been blurred and deformed owing to Ti redistribution facilitated by grain boundary migration. The edges of some CL-euhedral crystals become CL-mottled by localized grain boundary migration along adjacent crystals that do not align perfectly. Throughout the veins, CL-mottled crystals are randomly oriented, indicating that small deviatoric stresses were sufficient to drive recrystallization and mobilization of trace elements. Ti concentrations in CL-mottled crystals (23-47 ppm Ti; mean of 31 ppm) overlap those of CL-euhedral dark growth bands (16-40 ppm Ti; mean of 25 ppm Ti) in neighboring CL-euhedral crystals. Average Ti concentrations in CL-mottled quartz and CL-euhedral dark growth bands correspond to temperature estimates of 600°C (31 ppm Ti; CL-mottled) and 619°C (25 ppm Ti; dark bands), which are in good agreement with previous quartz precipitation temperature estimates based on independent thermobarometers. We conclude that recrystallization resets CL-mottled Ti concentrations close to the equilibrium value for the conditions of deformation and that CL-dark growth bands record near-equilibrium Ti concentrations. Recognition of widespread quartz recrystallization in porphyry Cu deposits underscores the significant role that strain plays in deposit formation. Individual veins host crystals that preserve conditions of primary growth and other crystals that preserve conditions of deformation and thermal overprint. Textural information is key to accurately interpreting trace element data and identifying different stages of vein formation. Our suggestion that CL-dark bands are the best candidates for near-equilibrium growth will aid the interpretation of trace element zoning in other hydrothermal systems.

Intensity simulation of photic effects after cataract surgery for off-axis light sources.

Photopsia is a photic phenomenon that can be associated with intraocular lenses after cataract surgery. To calculate the relative light intensity of photic effects observed after cataract surgery at the foveal region as the most sensitive region of the retina, photopsia was simulated using the ZEMAX optical design software. The simulations are based on the Liou-Brennan eye model with a pupil diameter of 4.5 mm and incorporating implanted IOLs. The hydrophilic IOLs implanted in the eye model have a power of 21 diopter (D) with an optic diameter of 6 mm and 7 mm. Four different intensity detectors are located in specific regions of the eye in this simulation. The ray-tracing analysis was carried out for variations of incident ray angle of 0° to 90° (temporally) in steps of 1°. Depending on the range of incident ray angle, the light intensity was detected at detectors located on the fovea, nasal side of the retina, or the edge surface of the IOLs. Some portion of the input light was detected at specific incident angles in the foveal region. By altering the IOLs edge design to a fully reflective or anti-reflective surface, the range over which the light intensity is detected on the fovea can be shifted. Additionally, with the absorbing edge design, no intensity was detected at the foveal region for incident ray angles larger than 5°. Therefore an absorbing edge design can make photic effects less disturbing for patients.

Mice lacking proSAAS display alterations in emotion, consummatory behavior and circadian entrainment.

ProSAAS is a neuroendocrine protein that is cleaved by neuropeptide-processing enzymes into more than a dozen products including the bigLEN and PEN peptides, which bind and activate the receptors GPR171 and GPR83, respectively. Previous studies have suggested that proSAAS-derived peptides are involved in physiological functions that include body weight regulation, circadian rhythms and anxiety-like behavior. In the present study, we find that proSAAS knockout mice display robust anxiety-like behaviors in the open field, light-dark emergence and elevated zero maze tests. These mutant mice also show a reduction in cued fear and an impairment in fear-potentiated startle, indicating an important role for proSAAS-derived peptides in emotional behaviors. ProSAAS knockout mice exhibit reduced water consumption and urine production relative to wild-type controls. No differences in food consumption and overall energy expenditure were observed between the genotypes. However, the respiratory exchange ratio was elevated in the mutants during the light portion of the light-dark cycle, indicating decreased fat metabolism during this period. While proSAAS knockout mice show normal circadian patterns of activity, even upon long-term exposure to constant darkness, they were unable to shift their circadian clock upon exposure to a light pulse. Taken together, these results show that proSAAS-derived peptides modulate a wide range of behaviors including emotion, metabolism and the regulation of the circadian clock.

The sphere of influence of the bright central galaxies in the diffuse light of SDSS clusters

ABSTRACT The bright central galaxies (BCGs) dominate the inner portion of the diffuse cluster light, but it is still unclear where the intracluster light (ICL) takes over. To investigate the BCG–ICL transition, we stack the images of ∼3000 clusters between 0.2 < $\mathit{ z}$ < 0.3 in the Sloan Digital Sky Survey (SDSS) gri bands, and measure their BCG + ICL stellar surface mass profile $\Sigma _{*}^{\texttt {B+I}}$ down to $3{\times }10^4\,\mathrm{ M}_{\odot }\,\mathrm{kpc}^{-2}$ at $R{\simeq }1\, \mathrm{Mpc}$ (∼32 mag arcsec−2 in the r-band). We develop a physically motivated method to decompose $\Sigma _{*}^{\texttt {B+I}}$ into three components, including an inner de Vaucouleurs’ profile, an outer ICL that follows the dark matter distribution measured from weak lensing, and an intriguing transitional component between 70 and 200 kpc. To investigate the origin of this transition, we split the clusters into two subsamples by their BCG stellar mass $M_*^{\mathrm{BCG}}$ (mass enclosed roughly within 50 kpc) while making sure they have the same distribution of satellite richness. The $\Sigma _{*}^{\texttt {B+I}}$ profiles of the two subsamples differ by more than a factor of 2 at R < 50 kpc, consistent with their 0.34 dex difference in $M_*^{\mathrm{BCG}}$, whereas on scales beyond 400 kpc, the two profiles converge to the same amplitudes, suggesting a satellite-stripping origin of the outer ICL. Remarkably, however, the discrepancy between the two $\Sigma _{*}^{\texttt {B+I}}$ profiles persists at above $50{{\ \rm per\ cent}}$ level on all scales below 200 kpc, thereby revealing the BCG sphere of influence with radius RSOI ≃ 200 kpc. Finally, we speculate that the surprisingly large sphere of influence of the BCG is tied to the elevated escape velocity profile within rs, the characteristic radius of the dark matter haloes.

Transcriptomic Analysis for Pork Color—The Ham Halo Effect in Biceps Femoris

Pork color is a major indicator of product quality that guides consumer purchasing decisions. Recently, industryhas received an increase in consumer complaints about the lightness and nonuniformity of ham color, primarily lighter colorin the periphery termed “ham halo” that is not caused by manufacturing procedures. This effect is seen in fresh and processed hams and the outer lighter muscle is associated with lower myoglobin concentration, pH, and type I fibers. The objective of this study was to identify differences in gene expression profiles between light and normal-colored portions of the biceps femoris muscle from pork hams. RNA-sequencing (RNA-seq) was performed for paired light and normal-colored muscle samples from 10 animals showing the ham halo effect. Over 50 million paired-end reads (2×75 bp) per library were obtained. An average of 99.74% of trimmed high-quality reads was mapped to the Sscrofa 11.1 genome assembly. Differentially expressed genes (DEGs) were identified using both the DESeq2 and GFOLD software packages. A total of 14,049 genes were expressed in the biceps femoris; 13,907 were expressed in both light and normal muscle, while 56 and 86 genes were only expressed in light and normal muscle, respectively. Analysis with DESeq2 identified 392 DEGs with 359 genes being more highly expressed in normal-colored muscle. A total of 61 DEGs were identified in the DESeq2 analysis and identified in at least 7 of the 10 individual animal analyses. All 61 of these DEGs were up-regulated in normal-colored muscle. Gene Ontology enrichment analysis of DEGs identified the transition between fast and slow fibers and skeletal muscle adaptation and contraction as the most significant biological process terms. The evaluation of gene expression by RNA-seq identified DEGs between regions of the biceps femoris with the ham halo effect that are associated with variation in pork color.

Temperature compensated curvature sensor with insensitive axial strain based on tapered ring core fiber interferometer

An all fiber temperature compensated curvature sensor with insensitive axial strain is proposed and experimentally demonstrated. The sensor is fabricated by a 2 cm ring core fiber (RCF) which is spliced between single mode fibers (SMFs) with two up-tapers, and a Mach–Zehnder Interferometer (MZI) is formed. The simulation results show that the first up-taper scatters a portion of the input light that should be in the ring core into the outer cladding, and then the ring core modes interfere with the cladding modes distributed in both inner cladding and outer cladding. The interference dips of this structure respond differently to curvature and temperature, so a calibration matrix can be established to implement temperature compensation. Experimental results show that this structure offers a maximum curvature sensitivity of −3.504 nm/m−1 in the range from 1.316 m−1 to 2.372 m−1 with a high linear regression coefficient value of 0.9971, and a maximum temperature sensitivity of 59.42 pm/°C is obtained in the range from 25 °C to 60 °C. We also test the axial strain characteristics of this structure and the results imply a minimum cross sensitivity of 8.086 × 10−5 m−1/με which is extremely low. This indicates that our sensor has axial strain insensitivity which will improve its measurement accuracy.