Diurnal activity rhythms and time budgets of captive Qinling golden takin(Budorcas taxicolor bedfordi) in the Qinling Mountains,Shaanxi,China

In July 2006, the diurnal activity rhythms of 13 heads of captive Qinling golden takin were observed in Shaanxi Provincial Centre for the Breeding and Conservation of Rare Wildlife （SPCBCRW） at daylight （from 9：00 am to 4：00 pm in July）. The behavioral ethnogram was identified through observation at the sampling site, with the behaviors of golden takin recorded at 5 min interval using instantaneous scannable sampling method. The results indicated that the resting of golden takin took an important part in the daylight activities. Meanwhile, drinking and urinating and defecating were 1.92 and 0.54 and 0.92 times per head per day. Ambient temperature had a strong effect on the diurnal activity rhythms of golden takin. The diurnal activity rhymes were affected by ages of the animals effectively, which was expressed through differentiation of the time budgets. Moreover, different individuals in the same population showed some non-synchronously activity rhythms.

Root Secretion of Phytochemicals in Arabidopsis Is Predominantly Not Influenced by Diurnal Rhythms

Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors like temperature and soil moisture. It has been suggested that root secretion of specific flavonoids is influenced by diurnal rhythms （by light or dark） but a comprehensive analysis of the overall secretion of phytochemicals in response to diurnal rhythms has not been studied. In this study, we analyzed the effect of light/dark cycles on root exudation profiles using Arabidopsis as a model plant. Our results reveal that the root secretion of phytochemicals is partly regulated by the diurnal light cycle and follows two main patterns of secretion： （1） the large majority of phytochemicals in the exudates showed no diurnal pattern in their secretion, and （2） a few compounds showed a diurnal pattern in their secretion： three compounds increased in secretion only under light; two compounds increased in secretion only while it was dark; and two compounds increased in secretion during the transition from dark to light. Root-specific ABC transporters have been implicated in root exudation; an analysis of the gene expression patterns of ABC transporters in the roots of Arabidopsis at specific time points revealed that none of the ABC transporters followed a diurnal expression pattern, suggesting that they are expressed constantly during the day and night. Similarly, we analyzed the expression in roots of genes involved in secondary metabolite biosynthesis and found that some of the genes involved in phenylpropanoid and glucosinolate biosynthesis （i.e. 4-coumarate-CoA ligases （4CL1 and 4CL2）, flavonol synthases （FSl and FS2）, and CYP79B3） followed distinct diurnal expression patterns. Overall, we have discovered that while root exudation of the majority of phytochemicals is constitutive, the secretion of a few compounds follows a diurnal rhythm, which is in accordance with the expression of some genes involved in secondary metabolism.

Leaf Volatiles from Host Tree Acer negundo : Diurnal Rhythm and Behavior Responses of Anoplophora glabripennis to Volatiles in Field

The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.

Diurnal Rhythm of Antioxidant Biomarkers in Equines

The aim of the present study was to test the hypothesis that glutathione peroxidase, uric acid, and a number of hematological biomarkers do not vary in adult mares, over a 24-hour period. Seven adult (age 10 ± 6 yrs;weight 370 ± 30 kg) Arabian Purebred mares were used. Blood samples were collected every two hours, except during the period after-meals, when samples were collected every 30 minutes, totaling four samples in two hours. These samples were used to analyze glutathione peroxidase (GPx), uric acid (UA), glucose (GLU), total plasma protein (TPP), red blood cells (RBC), hemoglobin (HB), hematocrit (HT), red cell distribution width (RDW), white blood cells (WBC) and lymphocytes (LYM). One-way repeated measures analysis of variance (ANOVA) was used to determine significant differences. Tukey’s test was used for multiple comparisons between the averages. Ρ

Reconstruction and Dynamics of the Human Intestinal Microbiome Observed In Situ

The human gut microbiome has primarily been studied through the use of fecal samples,a practice that has generated vital knowledge on the composition and functional capacities of gastrointestinal microbial communities.However,this reliance on fecal materials limits the investigation of microbial dynamics in other locations along the gastrointestinal tract(in situ),and the infrequent availability of fecal samples prevents analysis at finer temporal scales(e.g.,hours).In our study,we utilized colonic transendoscopic enteral tubing,a technology originally developed for fecal microbiota transplantation,to sample the ileocecal microbiome twice daily;metagenomic and metatranscriptomic analyses were then conducted on these samples.A total of 43 ileocecal and 28 urine and fecal samples were collected from five healthy volunteers.The ileocecal and fecal microbiomes,as profiled in the five volunteers,were found to be similar in metagenomic profiling,yet their active genes(metatranscriptome)were found to be highly distinct.Both microbiomes were perturbed after laxative exposure;over time,they exhibited reduced dissimilarity to their pre-treatment state,thereby demonstrating resilience as an innate property of the gut microbiome,although they did not fully recover within our observation time window.Sampling of the ileocecal microbiome during the day and at night revealed the existence of diurnal rhythms in a series of bacterial species and functional pathways,particularly those related to short-chain fatty acid production,such as Propionibacterium acnes and coenzyme A biosynthesis Ⅱ.Autocorrelation analysis and fluctuations decomposition further indicated the significant periodicity of the diurnal oscillations.Metabolomic profiling in the fecal and urine samples mirrored the perturbance and recovery in the gut microbiome,indicating the crucial contribution of the gut microbiome to many key metabolites involved in host health.This study provides novel insights into the human gut microbiome and its inner resilience and diurnal rhythms,as well as the potential consequences of these to the host.

Uridine dynamic administration affects the circadian variation of bile acid metabolism in high-fat-diet-fed mice

High-fat diet(HFD)is demonstrated to disturb the bile acid metabolism.The rhythm of bile acid metabolism can also be affected by uridine,whose metabolism exhibits a daily rhythm.However,the mechanism of dynamic uridine administration affecting bile acid during HFD remains unclear.In this study,C57BL/6J mice were fed HFD(the control group;CON)or HFD with oral administration of uridine in the daytime(DUR)and nighttime(NUR)to investigate the mechanism of the effect of uridine on the bile acid.This study showed that the mRNA expression of uridine transporters and circadian clock genes in the jejunum was affected by zeitgeber time(ZT)(P<0.001).Genes related to the metabolism of pyrimidines in the liver showed a high dependence on daily rhythm(P<0.01),and DUR remarkably up-regulated the expression of ribonucleotide reductase regulatory subunit M2(RRM2)(P<0.05)compared to the CON group.Importantly,the mRNA expression of bile acids nuclear receptors,bile acid synthesis,and transporters in the liver showed significantly rhythmically changed(P<0.05),and the expression of cholesterol 7-alpha-hydroxylase(CYP7A1),fibroblast growth factor receptor 4(FGFR4),Na^(+)/taurocholate co transporting polypeptide(NTCP),and bile salt export pump(BSEP)mRNAs of mice with uridine administration increased significantly(P<0.05).The mRNA expression of the transporters of cholesterol and bile acids in the ileum was also affected by ZT(P<0.01)and significantly dependent on uridine administration(P<0.05).The expression of FXR and SHP was significantly affected by ZT and uridine,respectively.In conclusion,dynamic administration of uridine could regulate the rhythm of gene expression of pyrimidine and bile acid metabolism in the liver and ileum of HFD-fed mice,which contributed to the further study of circadian rhythmic physiological and pathological changes of bile acids.

Time of sunrise and hours with daylight may have an effect on the seasonality and diurnal variation of heart attack

Background The time of onset of myocardial infarction shows seasonal and daily variation. We aimed to investigate whether the number of hours with daylight has an effect on the seasonal variation of heart attack, and whether the time of sunrise has an effect on the diurnal rhythm of myocardial infarction. Methods We carried out a retrospective database study covering all patients admitted to any acute care hospital with the diagnosis of myocardial infarction in Hungary between January 2004 and December 2005 （n=32 329）. Data were collected from the National Health Insurance Fund Administration （OEP） according to the International Classification of Diseases （ICD 121, 122） and National Meteorology Service （OMSZ）. In case of patients who occurred in the database several times the events have been considered as a separate case. Results With consideration to seasonal variation, the peak period of heart attack was found in the spring, with the lowest number of events in the summer. The number of hours with daylight showed a weak negative correlation with the occurrence of myocardial infarction （r=-0.108, P 〈0.05）. With respect to diurnal variation, the peak period of daily events was between 6-12 in the morning （35.57%）. We have found a positive correlation between the time of sunrise and sunset and the occurrence of myocardial infarction （P 〈0.01）. Conclusion Based on our findings, the number of hours with daylight and the time of sunrise may be connected with the chances of having heart attack; however other factors, such as high blood pressure, diabetes or smoking may also have an influence.

Shifting Nicotiana attenuata's diurnal rhythm does not alter its resistance to the specialist herbivore Manduca sexta

Arabidopsis thaliana plants are less resistant to attack by the generalist lepidopteran herbivore Trichoplusia ni when plants and herbivores are entrained to opposite, versus identical diurnal cycles and tested under constant conditions. This effect is associated with circadian fluctuations in levels of jasmonic acid, the transcription factor MYC2, and glucosinolate contents in leaves. We tested whether a similar effect could be observed in a different plant-herbivore system： the wild tobacco Nicotiana attenuata and its co-evolved specialist herbivore, Manduca sexta. We measured larval growth on plants under both constant and diurnal conditions following identical or opposite entrainment, profiled the metabolome of attacked leaf tissue, quantified specific metabolites known to reduce M. sexta growth, and monitored A/I. sexta feeding activity under all experimental conditions. Entrainment did not consistently affect NI. sexta growth or plant defense induction. However, both were reduced under constant dark conditions,as was M. sexta feeding activity. Our data indicate that the response induced by NI. sexta in N. attenuata is robust to diurnal cues and independent of plant or herbivore entrain- ment. We propose that while the patterns of constitutive or general damage-induced defense may undergo circadian fluctuation, the orchestration of specific induced responses is more complex.

Characterization of Congestive Heart Failure by the Pattern of Diurnal Rhythm Based on Heart Rate Variability

The impaired autonomic nervous system(ANS) has a close relationship to morbidity and mortality for congestive heart failure(CHF). This study is aimed to investigate the possibility to characterize CHF by the pattern of diurnal rhythm based on heart rate variability(HRV). Two datasets of CHF(n=44) were from Physio Net. And the datasets of the normal from THEW(n=189). Two 2 h episodes representing day and night in resting state were selected in each Holter record. Measures concerning time domain, AR model-based analysis, symbol dynamic analysis, and non-Gaussian indexes(λ) were calculated in each episode. The diurnal rhythm was represented by the ratio of an index in the day to that at night. Results demonstrated different patterns of diurnal rhythm among the normal, mild CHF(NYHAI-Ⅱ) and severe CHF(NYHA Ⅲ-Ⅳ),reflecting the changes in sympathetic and vagal interaction from reciprocal function to accentuated antagonism due to CHF. Furthermore, using RRIn,(LFnu)d/(LFnu)nand λd/λn,the sensitivity and specificity for discriminating the normal and CHF reached 95.45%and 95.24%;And for discriminating between mild CHF and severe CHF were 84.38%and 91.67%. Our proposed method is promising in assessing the ANS state and monitoring therapeutic effects for CHF patients.

BBX7 interacts with BBX8 to accelerate flowering in chrysanthemum

The quantitative control of FLOWERING LOCUS T(FT)activation is important for the floral transition in flowering plants.However,the flowering regulation mechanisms in the day-neutral,summer-flowering chrysanthemum plant remain unclear.In this study,the chrysanthemum BBX7 homolog CmBBX7 was isolated and its flowering function was identified.The expression of CmBBX7 showed a diurnal rhythm and CmBBX7 exhibited higher expression levels than CmBBX8.Overexpression of CmBBX7 in transgenic chrysanthemum accelerated flowering,whereas lines transfected with a chimeric repressor(pSRDX-CmBBX7)exhibited delayed flowering.Yeast single hybridization,luciferase,electrophoretic mobility shift,and chromatin immunoprecipitation assays showed that CmBBX7 directly targets CmFTL1.In addition,we found that CmBBX7 and CmBBX8 interact to positively regulate the expression of CmFTL1 through binding to its promoter.Collectively,these results highlight CmBBX7 as a key cooperator in the BBX8–FT module to control chrysanthemum flowering.