Light Cycle Research Articles

Altered circadian expression of clock genes and clock-regulatory epigenetic modifiers in saliva of children with fetal alcohol spectrum disorders

Prenatal alcohol-exposed (AE) infants and children often demonstrate disrupted sleep patterns, including more frequent awakenings, reduced total sleep time, and more night-to-night sleep variability. Despite the strong connection between sleep patterns and circadian rhythmicity, relatively little is known about circadian rhythm disruptions in individuals with AE. Recently, several reports demonstrated that evaluating the expression patterns of human clock genes in biological fluids could reveal an individual’s circadian phenotype. Human saliva offers an emerging and easily available physiological sample that can be collected non-invasively for core-clock gene transcript analyses. We compared the expression patterns of core-clock genes and their regulatory genes in salivary samples of children aged 6–10 years-old with and without AE during the light cycle between ZT0-ZT11. We isolated the RNA from the samples and measured the expression patterns of core clock genes and clock regulating genes using the human specific primers with quantitative real-time PCR. Analysis of core clock genes expression levels in saliva samples from AE children indicates significantly altered levels in expression of core-clock BMAL1, CLOCK, PER1-3 and CRY1,2, as compared to those in age-matched control children. We did not find any sex difference in levels of clock genes in AE and control groups. Cosinor analysis was used to evaluate the rhythmic pattern of these clock genes, which identified circadian patterns in the levels of core clock genes in the control group but absent in the AE group. The gene expression profile of a salivary circadian biomarker ARRB1 was rhythmic in saliva of control children but was arhythmic in AE children. Altered expression patterns were also observed in clock regulatory genes: NPAS2, NFL3, NR1D1, DEC1, DEC2, and DBP, as well as chromatin modifiers: MLL1, P300, SIRT1, EZH2, HDAC3, and ZR1D1, known to maintain rhythmic expression of core-clock genes. Overall, these findings provide the first evidence that AE disturbs the circadian patten expression of core clock genes and clock-regulatory chromatin modifiers in saliva.

Occurrence of Maize Leaf Spot Disease Caused by Leptosphaerulina australis in Yunnan, China.

Maize (Zea mays) is vital as a staple food and livestock feed crop. Yunnan is one of the main maize-producing provinces in China (National Bureau of Statistics, 2022). While corn production in Yunnan is lower than the national average, the development of drought-tolerant varieties has contributed to improving productivity. In August 2021, a new leaf spot disease on maize was observed in Lancang, Yunnan (22°26'38.11"N to 22°48'38.68"N, 99°48'15.13"E to 99°59'20.03"E), causing serious damages to maize production with incidence up to 76.19 %. Initially, small light yellow lesions were seen scattered on diseased maize leaves, round or polygon, measuring 0.3 to 2.0 cm in diameter. In the intermediate phase, these lesions sank, ruptured, and turned white with dark brown borders. In severe cases, they merged into large irregular patches, reaching up to 10 cm, leading to complete leaf necrosis. Small black ascomata were seen on the lesions. Tissue sections reveal perithecium embedded in leaves, measuring 94~145 μm in diameter. Symptomatic tissues were sterilized in 1.5% NaClO for 60s, and washed twice withsterile purified water, then plated on potato dextrose agar (PDA) at 25℃, 90% relative humidity (RH), and a 12-hour light cycle. 6 isolates were obtained from 2 diseased maize cultivars. In 20 days, the colony reached the edge of the PDA plate, the center darkening from white, featuring white aerial mycelium on top and black on the reverse side. Brown ascomata, solitary or clustered, measured 80.1~176.7 × 55.57~138.9 μm. The ellipsoid to oblong ascospores were 17.9~39.7 × 10.9~14.1 μm, and the bitunicate, thick-walled asci were 90.1~133.3 × 26.6~33.5 μm. The genomic DNA was extracted using the Chelex-100 method (Möller et al. 1992). For molecular identification, the ITS, LSU, and β-tubulin (Tub2) genes were amplified using primer pairs ITS1/ITS4 (White et al. 1990), LR0R/LR5 (Vilgalys et al. 1990) and Btub2Fd/Btub4Rd (Woudenberg et al. 2009), respectively. Sequencing was performed by Sangon Biotech (Shanghai) Co., Ltd. The sequenced loci (GenBank accession nos.: LSU, OL687348-53; ITS, OL617009-10, and OL664058-61; Tub2, OL741678-83) of the isolates exhibited 100%/ 99%/ 100% similarities with L. australis genes: LSU, MH868885; ITS, KF381084; Tub2, GU237541, respectively. Using MEGA 11.0, phylogenetic trees were constructed using the maximum-likelihood algorithm on concatenated sequences of LSU, ITS, and Tub2 for isolates LCMB1 to 6. The isolates clustered with two L. australis strains with 100 % bootstrap support (1,000 replicates). The results were consistent with the Bayesian Inference tree. The pathogenicity test used strain LCMB4 on six healthy maize plants during the heading period under natural conditions. Three leaves pre-plant were wounded with sterile sandpaper and sprayed with conidial suspension (106 spores ml-1, diluted in sterilized water) in the greenhouse at 28℃, 90% RH, and a 12-hour light cycle, with sterilized distilled water used for control. Inoculated leaves developed symptoms consistent with the described after 10 days, while control leaves remained symptomless. The same pathogen was re-isolated from the infected leaves, fulfilling Koch's postulates. Previously, L. australis has been isolated from turfgrass (Mitkowski et al. 2004), Alfalfa (Zhang et al. 2021), soil (Li et al. 2018), and Paris polyphylla var. chinensis (Fu et al. 2019), but not from maize. This is the first report of L. australis causing leaf spot on maize globally.

Unravelling the neuroendocrine system of nocturnal spawning regulated by circadian clock in the razor clam, Sinonovacula constricta

The razor clam (Sinonovacula constricta), as one of important cultivated molluscs, holds high economic importance. Unlike other bivalve species, S. constricta exclusively spawns at night, so the endogenous regulatory mechanisms driving spawning were preliminarily investigated. To identify crucial genes/proteins that may be involved in regulating nocturnal spawning, ovarian transcriptomes and phosphoproteomes were analysed at four diurnal time points (00:00/ZT16, 06:00/ZT22, 12:00/ZT28, 18:00/ZT34) in S. constricta. Transcriptome analysis revealed 503 and 25 differentially expressed genes (DEGs) when comparing ZT16 vs ZT28 and ZT22 vs ZT34, respectively. DEGs associated with energy and substance metabolism, were predominantly overexpressed in ZT16. Notably, genes related to the circadian clock, the neuro-endocrine system, and reproduction, such as clock, timeless homolog (htim), estradiol 17-beta-dehydrogenase (hsd17b11), 5-hydroxytryptamine receptor (htr), and forkhead box protein O (foxo), exhibited significant changes between the light and dark cycles (P < 0.05). Phosphoproteome analysis identified 177 differentially phosphorylated proteins at ZT16 vs ZT28, which were mainly involved in energy and substance metabolism. The association analysis showed that reproduction related proteins including FoxO were heightened phosphorylation at ZT28. Based on our findings, the circadian clock (clock, htim, etc.), neuro-endocrine system (hsd17bs, htr, gpcr, etc.), and reproduction (foxo and rptor) genes and protein phosphorylation all exhibited circadian rhythm fluctuations, suggesting that they may all be involved in nocturnal spawning of razor clams. These findings establish a foundation for understanding the molecular mechanisms underlying spawning and offer valuable insights into the artificial breeding of molluscs.

Abstract We114: Feeding Behavior Underlies the Circadian Rhythm in the Autonomic Input to the Heart and Heart Rate

Objective: The circadian pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus drives circadian rhythms in feeding and activity. Several studies suggest the SCN regulates autonomic input to the heart to generate day-night rhythms in heart rate. Hypothesis: The circadian rhythm in feeding generates day-night rhythms in autonomic input to the heart and heart rate. Methodology: Mice (n=6/sex) were implanted with telemetry probes to continuously record heart rate, core body temperature, and activity in thermoneutral housing conditions. Mice were housed in a 12 h light: 12 h dark cycle (LD) with ad libitum access to food (ALF). In these conditions, mice primarily eat during the dark cycle. Mice were subjected to light phase time-restricted feeding (TRF) for 5 days. This forces the mice to eat during the light cycle. We quantified changes in autonomic input to the heart by injecting mice with the autonomic receptor inhibitors propranolol and methylatropine. To determine if circadian rhythms generate day-night rhythms in autonomic input to the heart, TRF mice were switched from LD to constant darkness (DD) and then returned to ALF in DD. Results: ALF mice housed in LD had 24-hour rhythms in autonomic input to the heart, heart rate, and activity that all peaked in alignment during the dark cycle. One day after starting TRF, the phase of the 24-hour rhythms in heart rate but not activity shifted by 8-10 hours to align with feeding during the light phase. Switching TRF mice in LD to DD did not alter the phase or amplitude of the day-night rhythms in autonomic input to the heart, heart rate, or activity. Returning the TRF mice in DD to ALF showed the autonomic input to the heart and heart rate re-aligned with the free running rhythm in activity. Conclusions: Day-night rhythms in heart rate and autonomic input to the heart align with activity in LD and DD in ad libitum fed but not time-restricted fed conditions. These data demonstrate that feeding behavior, not SCN-signaling or activity rhythms, drives day-night rhythms in autonomic input to the heart and heart rate.

Divergent patterns of locomotor activity in cave isopods (Oniscidea: Styloniscidae) in Neotropics

ABSTRACT In cave environments, stable conditions devoid of light-dark cycles and temperature fluctuations sustain circadian clock mechanisms across various species. However, species adapted to these conditions may exhibit disruption of circadian rhythm in locomotor activity. This study examines potential rhythm loss due to convergent evolution in five semi-aquatic troglobitic isopod species (Crustacea: Styloniscidae), focusing on its impact on locomotor activity. The hypothesis posits that these species display aperiodic locomotor activity patterns. Isopods were subjected to three treatments: constant red light (DD), constant light (LL), and light-dark cycles (LD 12:12), totaling 1656 h. Circadian rhythm analysis employed the Sokolove and Bushell periodogram chi-square test, Hurst coefficient calculation, intermediate stability (IS), and activity differences for each species. Predominantly, all species exhibited an infradian rhythm under DD and LL. There was synchronization of the locomotor rhythm in LD, likely as a result of masking. Three species displayed diurnal activity, while two exhibited nocturnal activity. The Hurst coefficient indicated rhythmic persistence, with LD showing higher variability. LD conditions demonstrated higher IS values, suggesting synchronized rhythms across species. Significant individual variations were observed within species across the three conditions. Contrary to the hypothesis, all species exhibited synchronization under light-dark conditions. Analyzing circadian activity provides insights into organism adaptation to non-cyclical environments, emphasizing the importance of exploring underlying mechanisms.

Biochemical changes due to photothermal acclimation of Oedogonium and associated implications for photosynthetic growth and biomass utilisation

Freshwater filamentous algae have potential for wastewater bioremediation and bioproduct generation. This study investigated the separate and combined effects of growth irradiance regime (300 ± 25 μmol.m−2.s−1 with 13:11 dark:light cycle or 775 ± 25 μmol.m−2.s−1 with 8:16 dark:light cycle) and temperature (15 ± 1 or 25 ± 1 °C) during acclimation on the adaptive biochemistry and photosynthetic activity of Oedogonium with the higher and lower levels representing average outdoor conditions in summer and winter in Melbourne, Australia, respectively. Photoprotective pigments were upregulated in response to either high irradiance regime or temperature, while the chlorophyll content was also reduced when both stressors were combined. The upregulation of protective adaptations slightly lowered photosynthetic efficiency, which was more dramatically impaired by the reduced chlorophyll at high temperature and irradiance. The polar lipid content increased from ~10% to ~30% of total lipid content, the protein content decreased by ~10% and the starch content increased by 30% in response to higher irradiance and temperature, with implications for biomass utilisation. These changes in biochemical composition due to long-term acclimation suggests the potential for compositional stratification in stable floating filamentous algae mats due to the presence of self-shading. Further, the shading created by the upper layers in the mat can be expected to provide further protection to the biomass at the lower levels against photooxidative stress. The results reveal the impact of variations on seasonal growth conditions and filamentous mat depth on the composition and productivity of the algae.

Synchronized Photoactivation of T4K Rhodopsin Causes a Chromophore-Dependent Retinal Degeneration That Is Moderated by Interaction with Phototransduction Cascade Components.

Multiple mutations in the Rhodopsin gene cause sector retinitis pigmentosa in humans and a corresponding light-exacerbated retinal degeneration (RD) in animal models. Previously we have shown that T4K rhodopsin requires photoactivation to exert its toxic effect. Here we further investigated the mechanisms involved in rod cell death caused by T4K rhodopsin in mixed male and female Xenopus laevis In this model, RD was prevented by rearing animals in constant darkness but surprisingly also in constant light. RD was maximized by light cycles containing at least 1 h of darkness and 20 min of light exposure, light intensities >750 lux, and by a sudden light onset. Under conditions of frequent light cycling, RD occurred rapidly and synchronously, with massive shedding of ROS fragments into the RPE initiated within hours and subsequent death and phagocytosis of rod cell bodies. RD was minimized by reduced light levels, pretreatment with constant light, and gradual light onset. RD was prevented by genetic ablation of the retinal isomerohydrolase RPE65 and exacerbated by ablation of phototransduction components GNAT1, SAG, and GRK1. Our results indicate that photoactivated T4K rhodopsin is toxic, that cell death requires synchronized photoactivation of T4K rhodopsin, and that toxicity is mitigated by interaction with other rod outer segment proteins regardless of whether they participate in activation or shutoff of phototransduction. In contrast, RD caused by P23H rhodopsin does not require photoactivation of the mutant protein, as it was exacerbated by RPE65 ablation, suggesting that these phenotypically similar disorders may require different treatment strategies.

Effect of Ambient Lighting on Intraocular Pressure Rhythms in Rats.

The purpose of this study was to determine the effects of ambient lighting on intraocular pressure (IOP) rhythmicity and variability. IOP was continuously recorded by wireless telemetry from rats under light/dark (LD), dark/light (DL), asymmetric (6L18D and 18D6L), constant dark (DD), and constant light (LL) cycles. In some DD experiments, 1-hour light pulses were presented at varying times. IOP rhythmicity and variability were respectively quantified via cosinor analysis and peak detection algorithms that identified transient and sustained fluctuations. Rat IOP peaked at night and troughed during the day with LD amplitude of 8.7 ± 3.4mm Hg. Rhythmicity persisted in DD and LL with a free-running period of 24.1 ± 0.3 and 25.2 ± 0.4 hours, respectively. Peak-to-trough amplitude was approximately 60% smaller in LL, often disappeared after 1 to 2 weeks as daytime IOP drifted 2.6 ± 1.5mm Hg higher, and returned to approximately 60% larger in LD. Rhythmicity was similarly impacted but resynchronized to DL over 4 to 6days. Rhythmicity was unaltered by short photoperiods (6L18D), but the nocturnal IOP elevation was markedly shortened by long photoperiods (18L6D) and temporarily lowered to daytime levels by light pulses during the subjective night. Transient and sustained event rate, amplitude, interval, and energy content were nearly identical in LD, DD, and LL. Aqueous humor dynamics of rat eyes are intrinsically configured to set IOP at daytime levels. Circadian clock input modulates these dynamics to elevate IOP at night. Light at night blocks this input, sending IOP back to daytime levels. Effects of abnormal lighting on IOP rhythmicity may contribute to pressure-related ocular neuropathies.

Impacts of heat stress on the accuracy of an ear-tag accelerometer for monitoring rumination and eating behavior in dairy-beef cross cattle using an automated gold standard

Accelerometer-based technologies can be utilized for precision monitoring of feeding behaviors, but limited information is available regarding the impact of varying environmental conditions on sensor performance. The objective of this study was to determine if a commercially available ear-tag sensor (CM; CowManager SensOor, Agis Automatisering BV) could accurately quantify eating and rumination time under heat stress conditions. Data obtained from CM sensors was compared with data collected using an automated gold standard (RW; Rumiwatch System; Itin+Hoch). Automated measurements were obtained from 2 experiments in which cattle were exposed to heat stress conditions. In the principal study (Experiment 1), 3428 h of data were collected from 9 Holstein × Angus steers (470.9 ± 23.9 kg) subjected to either thermoneutral (TN; 21.0°C; 64.0% humidity; temperature-humidity index [THI] = 67; 12- and 12-h light and dark cycle; n = 1714 h), or heat stress conditions (HS; cyclical daily temperatures to mimic diurnal patterns; 0800 - 2000 h: 33.6°C, 40.0% RH, THI: 83.5; 2000 - 0800 h: 23.2°C, 70.0% RH; THI: 70.3; n = 1714 h). Data (n = 719 h) from 6 Holstein x Angus steers (487.9 ± 9.1 kg) were obtained from a subsequent experiment (Experiment 2) to confirm consistency of ear-tag accelerometer performance under elevated THI (HS conditions as described above). In Experiment 1, CM was capable of quantifying rumination time with high accuracy under TN conditions (concordance correlation coefficient [CCC]: 0.75 - 0.81). Overall, agreement between CM and the automated gold standard declined 6 - 7% during HS, which was most apparent later in the day when cattle had been subjected to HS for multiple hours (moderate agreement; CCC: 0.68). Accuracy for rumination time was also only moderate for data collected during Experiment 2 (CCC: 0.55 - 0.61). In contrast, CM reported total eating (eating with the head down + head up while masticating) time with moderate accuracy for TN (CCC: 0.53 - 0.54), only achieved negligible to low accuracy during HS (CCC: 0.39 - 0.44 [Experiment 1] and 0.17 - 0.34 [Experiment 2]). Sensor performance did improve when CM eating time was compared specifically to the time spent with the head down reported by RW; HS still negatively influenced sensor performance, however, with high agreement during TN (CCC: 0.72 - 0.73) but low to moderate agreement during HS (CCC: 0.65 - 0.69 [Experiment 1] and 0.40 - 0.58 [Experiment 2]). Results of this study suggest accuracy of ear-tag accelerometers may be impaired when cattle are subjected to heat stress.

Plantlet Regeneration from Callus Cultures of Kappaphycus alvarezii for Cultivation in Coastal Waters at Myeik Archipelago, Myanmar.

&lt;b&gt;Background and Objective:&lt;/b&gt; The cultivation of &lt;i&gt;Kappaphycus alvarezii&lt;/i&gt;, the most economically valuable rhodophyte seaweed species, began in Myanmar in 2004, primarily on islands in the Myeik Archipelago. Since &lt;i&gt;K. alvarezii&lt;/i&gt; is not native to Myanmar, it was initially imported from the Philippines and Indonesia. This study aimed to develop a tissue culture procedure for the generation of &lt;i&gt;K. alvarezii&lt;/i&gt; plantlets to ensure a continuous supply of seaweed for commercial farming in the coastal waters of Myanmar. &lt;b&gt;Materials and Methods:&lt;/b&gt; Specimens of &lt;i&gt;K. alvarezii&lt;/i&gt;, two-month-old, were procured in the Myeik Archipelago, Myanmar. After being cleared epiphytes and clinging materials, the specimens were placed in glass aquarium tanks with circulating seawater. Axenic explant culture was established using 1% povidone-iodine for 1 min and a 1% antibiotic mixture for 24 hrs. Plant growth regulators, 6-benzyl aminopurine (BAP) and indole 3 acetic acid (IAA) were supplemented in solid Provasoli's enriched seawater (PES) media to induce callus formation and somatic embryogenesis. &lt;b&gt;Results:&lt;/b&gt; The optimal culture conditions were incubation at 22-25°C under cool-white fluorescent-light (15-20 μmol photons/m&lt;sup&gt;2&lt;/sup&gt;/sec) with a 12:12 hrs light and dark cycle. Water quality during the culturing process was maintained at a pH of 8 and salinity of 30 PSU. The tissue-cultured &lt;i&gt;K. alvarezii&lt;/i&gt; plantlets exhibited an average daily growth rate of 9.70±0.25% over the growth period. &lt;b&gt;Conclusion:&lt;/b&gt; Therefore, plantlet regeneration from &lt;i&gt;K. alvarezii&lt;/i&gt; callus cultures can be utilized as seedlings for revenue-generating cultivation along the Myanmar coastline.

Reorganization of circadian activity and the pacemaker circuit under novel light regimes.

Many environmental features are cyclic, with predictable changes across the day, seasons and latitudes. Additionally, anthropogenic, artificial-light-induced changes in photoperiod or shiftwork-driven novel light/dark cycles also occur. Endogenous timekeepers or circadian clocks help organisms cope with such changes. The remarkable plasticity of clocks is evident in the waveforms of behavioural and molecular rhythms they govern. Despite detailed mechanistic insights into the functioning of the circadian clock, practical means to manipulate activity waveform are lacking. Previous studies using a nocturnal rodent model showed that novel light regimes caused locomotor activity to bifurcate such that mice showed two bouts of activity restricted to the dimly lit phases. Here, we explore the generalizability of these findings and leverage the genetic toolkit of Drosophila melanogaster to obtain mechanistic insights into this unique phenomenon. We find that dim scotopic illumination of specific durations induces circadian photoreceptor CRYPTOCHROME-dependent activity bifurcation in male flies. We show circadian reorganization of the pacemaker circuit, wherein the 'evening' neurons regulate the timing of both bouts of activity under novel light regimes. Our findings indicate that such environmental regimes can be exploited to design light cycles, which can ease the circadian waveform into synchronizing with challenging conditions.

Molecular events accompanying aggregation-induced energy quenching in fucoxanthin-chlorophyll proteins

In high light, the antenna system in oxygenic photosynthetic organisms switches to a photoprotective mode, dissipating excess energy in a process called non-photochemical quenching (NPQ). Diatoms exhibit very efficient NPQ, accompanied by a xanthophyll cycle in which diadinoxanthin is de-epoxidized into diatoxanthin. Diatoms accumulate pigments from this cycle in high light, and exhibit faster and more pronounced NPQ. The mechanisms underlying NPQ in diatoms remain unclear, but it can be mimicked by aggregation of their isolated light-harvesting complexes, FCP (fucoxanthin chlorophyll-a/c protein). We assess this model system by resonance Raman measurements of two peripheral FCPs, trimeric FCPa and nonameric FCPb, isolated from high- and low-light-adapted cells (LL,HL). Quenching is associated with a reorganisation of these proteins, affecting the conformation of their bound carotenoids, and in a manner which is highly dependent on the protein considered. FCPa from LL diatoms exhibits significant changes in diadinoxanthin structure, together with a smaller conformational change of at least one fucoxanthin. For these LL-FCPa, quenching is associated with consecutive events, displaying distinct spectral signatures, and its amplitude correlates with the planarity of the diadinoxanthin structure. HL-FCPa aggregation is associated with a change in planarity of a 515-nm-absorbing fucoxanthin, and, to a lesser extent, of diadinoxanthin. Finally, in FCPb, a blue-absorbing fucoxanthin is primarily affected. FCPs thus possess a plastic structure, undergoing several conformational changes upon aggregation, dependent upon their precise composition and structure. NPQ in diatoms may therefore arise from a combination of structural changes, dependent on the environment the cells are adapted to.

Diurnal sex differences in morphine withdrawal revealed by continuous assessment of voluntary home cage wheel running in the rat

Animal studies modeling recreational opioid use show more severe withdrawal symptoms in male compared to female rats, whereas our study modeling opioid use for pain showed a greater withdrawal-induced decrease in wheel running in female rats. The objective of this experiment was to determine whether sex differences in spontaneous morphine withdrawal are caused by differences in assessment method (i.e., wheel running vs. somatic symptoms). Twice daily injections of morphine (5 – 20 mg/kg, s.c.) for 5 days produced a dose and time dependent decrease in wheel running that was greater in male compared to female rats. Termination of morphine administration resulted in an overall decrease in running and a decrease in the amount of running during the dark phase of the light cycle from 95 % to approximately 75 %. In male rats, this decrease in the percent of dark running was caused by a large decrease in dark phase running, whereas female rats had a slightly higher increase in light phase running. Withdrawal also reduced maximal running speed and caused a decrease in body weight that was larger in male than female rats. Withdrawal symptoms were greatest on the day following the last morphine injection, but persisted for all 3 days of assessment. Morphine withdrawal produced a greater decrease in dark phase wheel running and body weight in male rats and a greater increase in light phase running in female rats. Voluntary home cage wheel running provides a continuous measure of opioid withdrawal that is consistent with other measures of opioid withdrawal.

Manipulation of feeding patterns in high fat diet fed rats improves microbiota composition dynamics, inflammation and gut-brain signaling

Chronic consumption of high fat (HF) diets has been shown to increase meal size and meal frequency in rodents, resulting in overeating. Reducing meal frequency and establishing periods of fasting, independently of caloric intake, may improve obesity-associated metabolic disorders. Additionally, diet-driven changes in microbiota composition have been shown to play a critical role in the development and maintenance of metabolic disorders. In this study, we used a pair-feeding paradigm to reduce meal frequency and snacking episodes while maintaining overall intake and body weight in HF fed rats. We hypothesized that manipulation of feeding patterns would improve microbiota composition and metabolic outcomes. Male Wistar rats were placed in three groups consuming either a HF, low fat diet (LF, matched for sugar), or pair-fed HF diet for 7 weeks (n = 11–12/group). Pair-fed animals received the same amount of food consumed by the HF fed group once daily before dark onset (HF-PF). Rats underwent oral glucose tolerance and gut peptide cholecystokinin sensitivity tests. Bacterial DNA was extracted from the feces collected during both dark and light cycles and sequenced via Illumina MiSeq sequencing of the 16S V4 region. Our pair-feeding paradigm reduced meal numbers, especially small meals in the inactive phase, without changing total caloric intake. This shift in feeding patterns reduced relative abundances of obesity-associated bacteria and maintained circadian fluctuations in microbial abundances. These changes were associated with improved gastrointestinal (GI) function, reduced inflammation, and improved glucose tolerance and gut to brain signaling. We concluded from these data that targeting snacking may help improve metabolic outcomes, independently of energy content of the diet and hyperphagia.

Study on the Identification, Biological Characteristics, and Fungicide Sensitivity of the Causal Agent of Strawberry Red Core Root Rot

Strawberry red core root rot disease affects the growth and yield of strawberry (Fragaria ananassa Duch), which leads to economic losses in China. The study employed a tissue separation method to isolate and identify the causal agent responsible for strawberry red core root rot. This was achieved by the observation of its morphological characteristics, sequencing analyses, and pathogenicity tests. The sensitivity of five chemical fungicides against the two species of Fusarium was determined using the mycelial growth rate method, and the biological characteristics of the two species were examined. The pathogens were identified as Fusarium solani and Fusarium oxysporum. The optimal conditions for the mycelial growth of F. solani and F. oxysporum were determined to be potato sucrose agar at 25 °C and pH 6, and potato dextrose agar at 30 °C and pH 8, respectively, with a 24:24 light cycle. The most suitable carbon and nitrogen sources for the mycelial growth of F. solani were sucrose and sodium nitrate (NaNO3), while for F. oxysporum, they were glucose and peptone. A fungicide sensitivity test indicated that Prochloraz had a good inhibitory effect on the growth of F. solani and F. oxysporum with EC50 values of 0.088 mg L−1 and 0.162 mg. The growth inhibition effect of Azoxystrobin to F. solani and Carbendazim to F. oxysporum was not obvious. This study provides a theoretical basis for further research on strawberry red core root disease and its prevention.

Custom Anchorless Object Detection Model for 3D Synthetic Traffic Sign Board Dataset with Depth Estimation and Text Character Extraction

This paper introduces an anchorless deep learning model designed for efficient analysis and processing of large-scale 3D synthetic traffic sign board datasets. With an ever-increasing emphasis on autonomous driving systems and their reliance on precise environmental perception, the ability to accurately interpret traffic sign information is crucial. Our model seamlessly integrates object detection, depth estimation, deformable parts, and text character extraction functionalities, facilitating a comprehensive understanding of road signs in simulated environments that mimic the real world. The dataset used has a large number of artificially generated traffic signs for 183 different classes. The signs include place names in Japanese and English, expressway names in Japanese and English, distances and motorway numbers, and direction arrow marks with different lighting, occlusion, viewing angles, camera distortion, day and night cycles, and bad weather like rain, snow, and fog. This was done so that the model could be tested thoroughly in a wide range of difficult conditions. We developed a convolutional neural network with a modified lightweight hourglass backbone using depthwise spatial and pointwise convolutions, along with spatial and channel attention modules that produce resilient feature maps. We conducted experiments to benchmark our model against the baseline model, showing improved accuracy and efficiency in both depth estimation and text extraction tasks, crucial for real-time applications in autonomous navigation systems. With its model efficiency and partwise decoded predictions, along with Optical Character Recognition (OCR), our approach suggests its potential as a valuable tool for developers of Advanced Driver-Assistance Systems (ADAS), Autonomous Vehicle (AV) technologies, and transportation safety applications, ensuring reliable navigation solutions.

Structured electrons with chiral mass and charge.

Chirality is a phenomenon with widespread relevance in fundamental physics, material science, chemistry, optics, and spectroscopy. In this work, we show that a free electron can be converted by the field cycles of laser light into a right-handed or left-handed coil of mass and charge. In contrast to phase-vortex beams, our electrons maintained a flat de Broglie wave but obtained their chirality from the shape of their expectation value in space and time. Measurements of wave function densities by attosecond gating revealed the three-dimensional shape of coils and double coils with left-handed or right-handed pitch. Engineered elementary particles with such or related chiral geometries should be useful for applications in chiral sensing, free-electron quantum optics, particle physics or electron microscopy.

First report of leaf spot disease caused by Cladosporium pseudocladosporioides on Lonicera caerulea L. in Heilongjiang Province, China.

Blue honeysuckle (Lonicera caerulea L.) has contributed to maintaining the forest's ecological balance and remarkable frost-resistant abilities, helping it withstand extremely cold conditions (-46 °C) and a wide pH range (5 to 8) (Sharma and Lee 2021). Between September 2022 and September 2023, leaf spots were observed on approximately 30% of blue honeysuckle plants of the 'Lanjingling' cultivar grown in a 1.13 ha field in Da Hinggan Ling Prefecture (50.32° N, 124.13° E) in Heilongjiang Province, China. The leaves of the affected plants displayed black-colored spots. To identify the causal agents, 10 healthy and symptomatic leaves were randomly collected from ten healthy and infected individual plants, respectively. Small (3 to 4 mm) segments of the symptomatic tissues were immersed in 5% sodium hypochlorite (NaOCl) for 3 min, rinsed three times with sterile distilled water, dried in a paper towel, and plated on 9-cm Petri dishes containing potato dextrose agar (PDA). Ten fungal colonies developed on the PDA plates with an isolation frequency of 100% from 10 symptomatic leaves, and all colonies displayed a morphology consistent with Cladosporium spp. (Bensch et al. 2018). Cladosporium-like fungi were not isolated from healthy leaves. Dark olive-colored mycelia were observed, with straight unbranched conidiophores bearing terminal light brown-colored limoniform conidia (1.80 to 4.50 × 2.10 to 12.60 μm) and surrounded by a thin line of white mycelium (Delisle-Houde et al. 2024). To confirm this identification, PCR amplification of two representative strains LD-299 and LD-300 genomic DNA was performed with ITS1/ITS4 (White et al. 1990) and ACT512F/ACT783R (Carbone and Kohn 1999) primers. Basic local alignment search tool (BLAST) analyses of the National Center for Biotechnology Information database showed that sequences of the ITS (PP600316, PP600317) and ACT (PP624334, PP624335) all revealed 100% (493/493 nt, 493/493 nt; 181/181 nt, 181/181 nt) shared identity with Cladosporium pseudocladosporioides strain ex-type MF473195 and HM148674 (Bensch et al. 2010), respectively. Using a neighbor-joining phylogenetic analysis based on the ITS and ACT sequences, isolates LD-299 and LD-300 clustered in the same clade of C. pseudocladosporioides. Therefore, based on its morphological characteristics and molecular phylogeny, the two isolates were identified as C. pseudocladosporioides (Cosseboom and Hu 2023). A pathogenicity test was performed using nine healthy two-year-old blue honeysuckle Lanjingling plants. Three plants were inoculated with either the LD-299 or the LD-300 conidial suspension (1 × 106 spores/ml) or with clean water as an experimental control (Aydoğdu et al. 2023). All plants were cultured in a greenhouse (28℃, 75% relative humidity, 12 h light and dark cycle), and each experiment was replicated three times. Typical leaf spot symptoms were first observed on the inoculated leaves after 10 days. Morphological and molecular characterization of re-isolated pathogens from the artificially infected leaves indicated that the two isolates were identical, thereby confirming Koch's postulates. Cladosporium pseudocladosporioides previously caused leaf spot disease on artichoke (Cynara scolymus) in Türkiye (Aydoğdu et al. 2023). To the best of our knowledge, this is the first report of C. pseudocladosporioides causing leaf spots on blue honeysuckle in China. Blue honeysuckle production losses due to the leaf spots are critical for growers. Therefore, further focus should be given to investigate the host range and geographic distribution of C. pseudocladosporioides.

Influence of Performance Packages on Fuel Consumption and Exhaust Emissions of Passenger Cars and Commercial Vehicles under WLTP

The transportation sector is responsible for about 16% of worldwide greenhouse gas emissions. Despite efforts for a sensible reduction by means of new technologies’ development, the average age of a vehicle fleet is 12.3 years in the European Union. In light of this, actions aiming at improving the efficiency of circulating vehicles can prove effective in the short to mid-term. Introducing performance packages in standard fuels could allow a reduction in the CO2 emissions of whole vehicle fleets without any modification to powertrain. Such a kind of additive is generally used in premium fuels; deposit control additives can reduce or control the deposits at intake valves and at nozzle holes with benefits for the fuel efficiency and exhaust emissions. Further improvements in combustion phasing can be achieved with cetane/octane improver. This paper aims to assess the influence of two performance packages on the exhaust emissions and fuel consumption of five vehicles set to be as representative as possible of circulating Italian passenger cars and light commercial fleet vehicles (LCVs). Based on the literature datasets, three Euro 4 vehicles were selected with a mileage representative of each single vehicle class: two passenger cars (one spark ignition and one diesel) and an LCV. Further, two diesel Euro 6 vehicles, a passenger car and an LCV, were tested to investigate the effect of fuel additives on the combustion of vehicles compliant with current homologation regulation. Exhaust emissions and fuel consumption were experimentally estimated on a chassis dynamometer over a worldwide harmonized light vehicles test cycle (WLTC) in a climate-controlled laboratory. Each vehicle was preliminarily tested when running with base fuel, then a 3000 km clean-up stage was performed using the additive package. Finally, WLTC tests were repeated. Results demonstrated the efficiency of the performance packages with a reduction between 1.2% (diesel Euro 6 passenger car) and 8.1% (diesel Euro 4 passenger car) in fuel consumption. Similar trends were found for CO2 emissions. Further, a sensible reduction in THCs, CO and PM was found for each vehicle class.

Analysis of lettuce transcriptome reveals the mechanism of different light/dark cycle in promoting the growth and quality.

Light/dark (L/D) cycle plays a crucial role in controlling the production and quality of vegetables. However, the mechanism of L/D cycle on vegetable growth and quality is scarce studied. To investigate the impact of L/D cycle on lettuce growth and quality, we designed three diel scenarios, including 16 hours of light and 8 hours of darkness (L16/D8), 12 hours of light and 6 hours of darkness (L12/D6), and 8 hours of light and 4 hours of darkness (L8/D4). By phenotypic analysis, we found that lettuce grew taller under the L8/D4 scenario than under L16/D8 light cycle scenarios. The physiological indexes showed that the lettuce leaves grown in the L8/D4 scenario exhibited greater enhancements in the levels of soluble protein, soluble sugar, and carotenoid content compared to the other scenarios. By comparing the expression levels under different diel scenarios (L16/D8 vs L12/D6, L16/D8 vs L8/D4, and L12/D6 vs L8/D4), we identified 7,209 differentially expressed genes (DEGs). Additionally, 3 gene modules that were closely related to L/D cycle of lettuce were selected by WGCNA analysis. The eigengenes of three gene modules were enriched in plant hormone signal transduction, sphingolipid metabolism, and nucleocytoplasmic transport pathways. Through network analysis, we identified six hub genes (CIP1, SCL34, ROPGEF1, ACD6, CcmB, and Rps4) in the three gene modules, which were dominant in plant circadian rhythms and greatly affected lettuce growth. qRT-PCR analysis confirmed the diurnal response patterns of the 6 hub genes in different treatments were significant. This study intensively enhanced our comprehension of the L/D cycle in the growth morphology, nutritional quality, and metabolic pathways of lettuce.