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Lighting in poultry production holds notable importance with the advancement and modernization of the industry, as it plays a significant role in the physiology and growth of broiler chickens. Increasing attention has been paid to the impacts of lighting management on growth performance, immune status, and welfare of meat-type chickens. It is essential to have an appropriate lighting regimen that includes the light source, intensity, duration, and wavelength of light to improve broilers' growth and behavior. By manipulating various physiological, immunological, and behavioral activities, altering the color of light has been acknowledged as a potent managerial strategy capable of mitigating an array of stressors in broiler chickens. Assessing animal welfare is necessary for animal behavior and product quality perspectives. Birds have a unique visual system, and their behavior is primarily mediated by vision. Different monochromatic light regimes can affect feed conversion ratio, modulating broiler chickens' systematic immune response and aggressive behavior. With the advancement of lighting technology, new possibilities have emerged to enhance traditional lighting programs in poultry houses. This review integrates recent findings on the use of monochromatic light and its impact on broilers' welfare, growth, and physiological response. [ABSTRACT FROM AUTHOR]

Lead (Pb), a heavy metal environmental pollutant, poses a threat to the health of humans and birds. Inflammation is one of the most common pathological phenomena in the case of illness and poisoning. However, the underlying mechanisms of inflammation remain unclear. The cerebellum and the thalamus are important parts of the nervous system. To date, there have been no reports of Pb inducing inflammation in animal cerebellums or thalami. Selenium (Se) can relieve Pb poisoning. Therefore, we aimed to explore the mechanism by which Se alleviates Pb toxicity to the cerebellums and thalami of chickens by establishing a chicken Pb or/and Se treatment model. Our results demonstrated that exposure to Pb caused inflammatory damage in cerebellums and thalami, evidenced by the characteristics of inflammation, the decrease in anti-inflammatory factors (interleukin (IL)-2 and interferon-γ (INF-γ)), and the increase in pro-inflammatory factors (IL-4, IL-6, IL-12β, IL-17, and nitric oxide (NO)). Moreover, we found that the IL-2/IL-17–NO pathway took part in Pb-caused inflammatory injury. The above findings were reversed by the supplementation of dietary Se, meaning that Se relieved inflammatory damage caused by Pb via the IL-2/IL-17–NO pathway. In addition, an up-regulated oxidative index malondialdehyde (MDA) and two down-regulated antioxidant indices (glutathione (GSH) and total antioxidant capacity (TAC)) were recorded after the chickens received Pb stimulation, indicating that excess Pb caused an oxidant/antioxidant imbalance and oxidative stress, and the oxidative stress mediated inflammatory damage via the GSH–IL-2 axis. Interestingly, exposure to Pb inhibited four glutathione peroxidase (GPx) family members (GPx1, GPx2, GPx3, and GPx4), three deiodinase (Dio) family members (Dio1, Dio2, and Dio3), and fifteen other selenoproteins (selenophosphate synthetase 2 (SPS2), selenoprotein (Sel)H, SelI, SelK, SelM, SelO, SelP1, SelPb, SelS, SelT, SelU, and selenoprotein (Sep)n1, Sepw1, Sepx1, and Sep15), suggesting that Pb reduced antioxidant capacity and resulted in oxidative stress involving the SPS2–GPx1–GSH pathway. Se supplementation, as expected, reversed the changes mentioned above, indicating that Se supplementation improved antioxidant capacity and mitigated oxidative stress in chickens. For the first time, we discovered that the SPS2–GPx1–GSH–IL-2/IL-17–NO pathway is involved in the complex inflammatory damage mechanism caused by Pb in chickens. In conclusion, this study demonstrated that Se relieved Pb-induced oxidative stress and inflammatory damage via the SPS2–GPx1–GSH–IL-2/IL-17–NO pathway in the chicken nervous system. This study offers novel insights into environmental pollutant-caused animal poisoning and provides a novel theoretical basis for the detoxification effect of Se against oxidative stress and inflammation caused by toxic pollutants. [ABSTRACT FROM AUTHOR]

Lead (Pb), a toxic environmental pollutant, is hazardous to the health of humans and birds. Bursa of Fabricius (BF) is a unique organ of birds. Toxic substances can attack BF and induce proteotoxicity. Increased heat shock proteins (HSPs) can induce oxidative damage. Selenium (Se) can alleviate harmful substance-caused oxidative damage. This study aimed to investigate whether Pb can cause oxidative damage and proteotoxicity, as well as Se reverse Pb-caused chicken BF toxicity. A model of chickens treated with Se and Pb alone and in combination was established. BFs were collected on days 30, 60, and 90. H&E and qRT-PCR were performed to observe the microstructure and to detect HSP27, HSP40, HSP60, HSP70, and HSP90 mRNA levels, respectively, in BFs. Multivariate correlation analysis and principal component analysis were conducted to explore the correlation among the five HSPs. In our results, Pb caused BF damage and up-regulated the five HSPs at three time points, causing oxidative damage and proteotoxicity via HSP27–HSP40–HSP70–HSP90 pathway. Furthermore, Pb caused time-dependent stress on HSP27, HSP40, HSP60, and HSP70. In addition, Se relieved Pb-caused damage and up-regulation of HSPs. Taken together, we concluded that Se alleviated Pb-caused oxidative injury and proteotoxicity in chicken BFs via the HSP27–HSP40–HSP70–HSP90 pathway. [ABSTRACT FROM AUTHOR]

Ordinary planar waveguide cannot support electromagnetic (EM) wave propagating at frequency below the cut-off frequency of the waveguide, due to the evanescent wave nature of the EM wave in such waveguide. We have found by theoretical analysis that extraordinary EM wave transmission could occur for transverse-electric modes at frequency below the cut-off frequency of the hollow waveguide by inserting different kinds of anisotropic metamaterials (AMMs) in the hollow waveguide. Such transmission of EM energy has no lower cut-off frequency and is due to the conversion of the evanescent wave into propagating mode inside the AMMs, which is quite different from that in the case of waveguide loaded with an isotropic left-handed material slab. We have verified the extraordinary phenomenon by performing circuit analog of the planar waveguide loaded with different kinds of AMMs through realization with transmission line metamaterials. [ABSTRACT FROM AUTHOR]

We analyze the subwavelength imaging using compensated bilayer of anisotropic metamaterials and study the material loss and retardation effect on the image properties. Through rigorous analysis of the electromagnetic wave transmission and numerical calculations of the electromagnetic field distribution, we demonstrate that the anisotropic bilayer lens exhibits a decreased sensitivity to material loss and retardation, therefore has a better image with subwavelength resolution than that of the isotropic perfect lens configuration. We find that this is due to the fact that the inhomogeneous evanescent waves that are responsible for image resolution beyond the diffraction limit have been converted to propagating waves in the anisotropic bilayer, resulting in less sensitive to material loss and retardation. [ABSTRACT FROM AUTHOR]

We have studied the electromagnetic wave propagation in two-dimensional anisotropic metamaterial (AMM) by realizing the AMM through periodic structure composed of anisotropically loaded transmission line (TL) network. The dispersion relation of the TL metamaterial is analyzed by rigorous periodic TL theory, which shows hyperbolic dispersion surface in phase space below certain critical frequency. Utilizing microstrip line technique, we have constructed an interface between isotropic normal medium and a particular type of AMM with properly designed normal TL mesh and the loaded TL network, respectively. The electromagnetic wave propagation in such system has been analyzed with the consideration of circuit losses using microwave circuit simulations. We directly demonstrate interesting phenomena including the total reflection with inversion of the critical angle at small incident angle as well as the oblique total transmission at large incident angle at the interface, which have good agreement with the theoretical prediction. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) is one of major air pollutants in intensive poultry houses, affecting chicken health. Circular RNA (circRNA) is a novel type of RNA that can regulate gene expression and be associated with various biological activities. However, the changes of circRNA caused by excess NH 3 in chickens have not been investigated. We found differentially expressed genes and morphological changes in the thymuses of chickens exposed to NH 3 on day 42. We used a combination of RNA deep sequencing, qRT-PCR, and bioinformatic analysis to explore regulatory mechanism of circRNA and mRNA. Transcriptional profiling results showed that 5 circRNA genes and 100 mRNA genes were significantly dyregulated by high NH 3. The results from GO items showed that immune response and the regulation of cytokine production were involved in the mechanisms of chickens exposed to NH 3. Co-expression analysis found that circRNA-mRNA network was correlated with oxidative stress and inflammation. NH 3 exposure decreased mRNA expression of antioxidant-related genes (GPx and GST4) and increased the mRNA expression of inflammation-related genes (IL-1β, IL-6, IL-8, and iNOS) in chicken thymuses. Histopathologic analysis demonstrated that NH 3 caused inflammatory injury in chicken thymuses. In conclusion, the co-expression of circRNA and mRNA took part in chicken thymus inflammatory injury caused by NH 3. Our study further enriches the mechanism of NH 3 toxicity on chickens, which may be valuable for human and animal health protection. Image 1 • Differential expression of circRNA was involved in the stress caused by NH 3 exposure. •Analysis of circRNA - mRNA mediated co - expression network involved in chicken exposed to NH 3. •NH 3 induces oxidative stress and inflammatory reaction in chicken thymuses. •NH 3 caused inflammatory injury in chicken thymuses. [ABSTRACT FROM AUTHOR]

The evolution and driving factors underlying dust activity in central Asia remain controversial, particularly in its effects on downwind regions. We present a Holocene dust storm activity record retrieved from the Tarim Basin (TB) and perform linear and nonlinear analyses on dust records from the TB and the Greenland areas. The results indicate a similar response of dust activities to total solar irradiance in both areas, and an outbreak of dust storms in the TB at ~3.5 kyr BP. We suggest that decreasing temperature in high northern latitudes, aided by solar activity change, reached a critical threshold near ~3.5 kyr BP. The resulting steepening of the meridional temperature gradient would have facilitated strengthening and southward shift of the Northern Hemisphere westerly jet, leading to the outbreak of dust storms through intensification of low level wind intensity and prolonged spring conditions in the Asian interior. Key Points: A possible tipping point of dust activity in central Asia at ~3.5 kyr BP was indicated by intensity and regime changes of dust recordWe identify similar response of dust activities in both central Asia and Greenland areas to solar activity changeInsolation and solar activity change drive dust storm outbreak in Asia by increased wind intensity and prolonged spring conditions [ABSTRACT FROM AUTHOR]

Lead (Pb) is an environmental pollutant and can damage organisms. Selenium (Se) can alleviate Pb poisoning. The present study aimed to investigate the alleviative effect of Se on Pb-induced immune toxicity in chicken hearts. One-hundred-and-eighty Hy-line male chickens were randomly divided into four groups at 7 days of age. The control group was offered a standard commercial diet (SD) and drinking water (DW); the Se group was offered SD supplemented with sodium selenite (SeSD) and DW; the Pb + Se group was offered SeSD and DW supplemented with lead acetate (PbDW); and the Pb group was offered SD and PbDW. Relative mRNA expression of inducible nitric oxide synthase (iNOS), interleukins (IL-2, IL-4, IL-6, IL-12β, IL-17 and IFN-γ), and heat shock proteins (HSP27, HSP40, HSP60, HSP70, and HSP90) were determined by means of quantitative real-time PCR. Relative protein expression of iNOS, HSP60, HSP70, and HSP90 was assessed, as well as nitric oxide (NO) content and iNOS activity in heart tissue. The results indicated a down-regulation of interleukin (IL)-2 and IFN-γ and an up-regulation of NO, iNOS, interleukins (IL-4, IL-6, IL-12β, IL-17), and heat shock proteins (HSP27, HSP40, HSP60, HSP70, and HSP90) in Pb-damaged hearts. Se alleviated all of the above Pb-induced changes. There were time-dependent effects on NO content, iNOS activity, and mRNA levels of iNOS, IL-2, IL-4, IL-6, IL-17, HSP27, HSP40, HSP60, HSP70, and HSP90 after Pb treatment in the chicken hearts. Se alleviated Pb-induced immune toxicity in the chicken hearts. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen sulfide (H 2 S) is widely accepted to be a signaling molecule that exhibits some potentially beneficial therapeutic effects at physiological concentrations. At elevated levels, H 2 S is highly toxic and has a negative effect on human health and animal welfare. Studies have shown that H 2 S exposure induces an immune function in mice, but there are few studies of the effect of continuous H 2 S exposure on immune organs in poultry. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H 2 S gas for 14, 28 and 42 days of age. After exposure, the bursa of Fabricius (BF) was harvested. The results showed that continuous H 2 S exposure reduced the body weight, abdominal fat percentage, and antibody titer in broilers. H 2 S exposure also decreased mRNA expression of IgA, IgM and IgG in the broiler BF. A histological study revealed obvious nuclear debris, and a few vacuoles in the BF, and an ultrastructural study revealed mitochondrial and nuclear damage to BF cells after H 2 S exposure for 42 d. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay suggested H 2 S exposure remarkably increased the number of TUNEL positive nuclei and significantly increased apoptotic index. The expression of apoptotic genes also confirmed that H 2 S inhalation damaged the broiler BF. Increased cytokines and reduced antioxidant responses were detected in the BF after exposure to H 2 S. Cytokines promoted inflammation and caused a Th1/Th2 imbalance. We suggest that continuous H 2 S intoxication triggers oxidative stress, inflammation, apoptosis and a Th1/Th2 imbalance in the BF, leading to immune injury in broilers. Graphical abstract fx1 Highlights • Excessive H 2 S reduce the growth characteristics of broiler chickens. • H 2 S exposure induce a Th1/Th2 imbalance and affected immunoglobulin production. • Apoptosis is one injury mechanism to the bursa of Fabricius caused by H 2 S. • Oxidative stress and inflammation are involved in H 2 S-induced immune injury in broilers. [ABSTRACT FROM AUTHOR]