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Frontiers in Plant Science 2023The fitness of self-progeny individuals is inferior to that of their outcrossed counterparts, resulting in a reduction in a plant population's ability to survive and...
The fitness of self-progeny individuals is inferior to that of their outcrossed counterparts, resulting in a reduction in a plant population's ability to survive and reproduce. To prevent self-fertilization, angiosperms with hermaphrodite flowers may exploit a variety of mechanisms, including synchronous dichogamy and self-incompatibility. Synchronous dichogamy involves two flowering morphs, with strict within-morph synchronization, thereby preventing not only autogamy and geitonogamy but also intra-morph mating. Self-fertilization is also prevented by self-incompatibility, a genetic mechanism that allows the identification and rejection of "self" pollen, thereby preventing both autogamy and geitonogamy. Here, I seek to provide a perspective of flowering in species exhibiting both synchronous (i.e., "Early" morph flowers open in the morning and "Late" morph flowers open in the afternoon) protandrous dichogamy (i.e., pollen dispersal before the stigma becomes receptive) and self-incompatibility.
PubMed: 37662155
DOI: 10.3389/fpls.2023.1226502 -
Journal of Vision Jan 2024The spectral shape, irradiance, direction, and diffuseness of daylight vary regularly throughout the day. The variations in illumination and their effect on the light...
The spectral shape, irradiance, direction, and diffuseness of daylight vary regularly throughout the day. The variations in illumination and their effect on the light reflected from objects may in turn provide visual information as to the time of day. We suggest that artists' color choices for paintings of outdoor scenes might convey this information and that therefore the time of day might be decoded from the colors of paintings. Here we investigate whether human viewers' estimates of the depicted time of day in paintings correlate with their image statistics, specifically chromaticity and luminance variations. We tested time-of-day perception in 17th- to 20th-century Western European paintings via two online rating experiments. In Experiment 1, viewers' ratings from seven time choices varied significantly and largely consistently across paintings but with some ambiguity between morning and evening depictions. Analysis of the relationship between image statistics and ratings revealed correlations with the perceived time of day: higher "morningness" ratings associated with higher brightness, contrast, and saturation and darker yellow/brighter blue hues; "eveningness" with lower brightness, contrast, and saturation and darker blue/brighter yellow hues. Multiple linear regressions of extracted principal components yielded a predictive model that explained 76% of the variance in time-of-day perception. In Experiment 2, viewers rated paintings as morning or evening only; rating distributions differed significantly across paintings, and image statistics predicted people's perceptions. These results suggest that artists used different color palettes and patterns to depict different times of day, and the human visual system holds consistent assumptions about the variation of natural light depicted in paintings.
Topics: Humans; Cognition; Color Perception; Paintings; Perception; Photic Stimulation; Vision, Ocular
PubMed: 38165679
DOI: 10.1167/jov.24.1.1 -
Cell Reports. Medicine Dec 2023Lipid homeostasis in humans follows a diurnal pattern in muscle and pancreatic islets, altered upon metabolic dysregulation. We employ tandem and liquid-chromatography...
Lipid homeostasis in humans follows a diurnal pattern in muscle and pancreatic islets, altered upon metabolic dysregulation. We employ tandem and liquid-chromatography mass spectrometry to investigate daily regulation of lipid metabolism in subcutaneous white adipose tissue (SAT) and serum of type 2 diabetic (T2D) and non-diabetic (ND) human volunteers (n = 12). Around 8% of ≈440 lipid metabolites exhibit diurnal rhythmicity in serum and SAT from ND and T2D subjects. The spectrum of rhythmic lipids differs between ND and T2D individuals, with the most substantial changes observed early morning, as confirmed by lipidomics in an independent cohort of ND and T2D subjects (n = 32) conducted at a single morning time point. Strikingly, metabolites identified as daily rhythmic in both serum and SAT from T2D subjects exhibit phase differences. Our study reveals massive temporal and tissue-specific alterations of human lipid homeostasis in T2D, providing essential clues for the development of lipid biomarkers in a temporal manner.
Topics: Humans; Lipid Metabolism; Subcutaneous Fat; Adipose Tissue, White; Lipids; Diabetes Mellitus, Type 2
PubMed: 38016481
DOI: 10.1016/j.xcrm.2023.101299 -
Nutrients Dec 2023Numerous observational studies have documented an association between the circadian rhythm and the composition of the gut microbiota. However, the bidirectional causal...
BACKGROUND
Numerous observational studies have documented an association between the circadian rhythm and the composition of the gut microbiota. However, the bidirectional causal effect of the morning chronotype on the gut microbiota is unknown.
METHODS
A two-sample Mendelian randomization study was performed, using the summary statistics of the morning chronotype from the European Consortium and those of the gut microbiota from the largest available genome-wide association study meta-analysis, conducted by the MiBioGen consortium. The inverse variance-weighted (IVW), weighted mode, weighted median, MR-Egger regression, and simple mode methods were used to examine the causal association between the morning chronotype and the gut microbiota. A reverse Mendelian randomization analysis was conducted on the gut microbiota, which was identified as causally linked to the morning chronotype in the initial Mendelian randomization analysis. Cochran's Q statistics were employed to assess the heterogeneity of the instrumental variables.
RESULTS
Inverse variance-weighted estimates suggested that the morning chronotype had a protective effect on Family ( = -0.072; 95% CI: -0.143, -0.001; = 0.047), Genus ( = -0.112; 95% CI: -0.184, -0.039; = 0.002), and Genus ( = -0.072; 95% CI: -0.143, -0.001; = 0.047). In addition, the gut microbiota (Family (OR = 0.925; 95% CI: 0.857, 0.999; = 0.047), Genus (OR = 0.915; 95% CI: 0.858, 0.975; = 0.007), and Genus (OR = 0.925; 95% CI: 0.857, 0.999; = 0.047)) demonstrated positive effects on the morning chronotype. No significant heterogeneity in the instrumental variables, or in horizontal pleiotropy, was found.
CONCLUSION
This two-sample Mendelian randomization study found that Family , Genus , and Genus were causally associated with the morning chronotype. Further randomized controlled trials are needed to clarify the effects of the gut microbiota on the morning chronotype, as well as their specific protective mechanisms.
Topics: Bacteroides; Bacteroidetes; Chronotype; Gastrointestinal Microbiome; Genome-Wide Association Study; Mendelian Randomization Analysis
PubMed: 38201876
DOI: 10.3390/nu16010046 -
Osteoarthritis and Cartilage Sep 2023Spinal osteoarthritis is difficult to study and diagnose, partly due to the lack of agreed diagnostic criteria. This systematic review aims to give an overview of the... (Review)
Review
OBJECTIVE
Spinal osteoarthritis is difficult to study and diagnose, partly due to the lack of agreed diagnostic criteria. This systematic review aims to give an overview of the associations between clinical and imaging findings suggestive of spinal osteoarthritis in patients with low back pain to make a step towards agreed diagnostic criteria.
DESIGN
We searched MEDLINE, Embase, Web of Science, and CINAHL from inception to April 29, 2021 to identify observational studies in adults that assessed the association between selected clinical and imaging findings suggestive of spinal osteoarthritis. Risk of bias was assessed using the Newcastle Ottawa Scale and the quality of evidence was graded using an adaptation of the GRADE approach.
RESULTS
After screening 7902 studies, 30 met the inclusion criteria. High-quality evidence was found for the longitudinal association between low back pain (LBP) intensity, and both disc space narrowing and osteophytes, as well as for the association between LBP-related physical functioning and lumbar disc degeneration, the presence of spinal morning stiffness and disc space narrowing and for the lack of association between physical functioning and Schmorl's nodes.
CONCLUSIONS
There is high- and moderate-quality evidence of associations between clinical and imaging findings suggestive of spinal osteoarthritis. However, the majority of the studied outcomes had low or very low-quality of evidence. Furthermore, clinical and methodological heterogeneity was a serious limitation, adding to the need and importance of agreed criteria for spinal osteoarthritis, which should be the scope of future research.
Topics: Adult; Humans; Osteoarthritis, Spine; Low Back Pain; Lumbar Vertebrae; Intervertebral Disc Degeneration; Intervertebral Disc Displacement
PubMed: 37150286
DOI: 10.1016/j.joca.2023.04.014 -
International Journal of Molecular... Aug 2023Rheumatoid arthritis (RA) represents one of the best examples of circadian fluctuations in disease severity. Patients with RA experience stiffness, pain, and swelling in... (Review)
Review
Rheumatoid arthritis (RA) represents one of the best examples of circadian fluctuations in disease severity. Patients with RA experience stiffness, pain, and swelling in afflicted joints in the early morning, which tends to become milder toward the afternoon. This has been primarily explained by the higher blood levels of pro-inflammatory hormones and cytokines, such as melatonin, TNFα, IL-1, and IL-6, in the early morning than in the afternoon as well as insufficient levels of anti-inflammatory cortisol, which rises later in the morning. Clinical importance of the circadian regulation of RA symptoms has been demonstrated by the effectiveness of time-of-day-dependent delivery of therapeutic agents in chronotherapy. The primary inflammatory site in RA is the synovium, where increased macrophages, T cells, and synovial fibroblasts play central roles by secreting pro-inflammatory cytokines, chemokines, and enzymes to stimulate each other, additional immune cells, and osteoclasts, ultimately leading to cartilage and bone erosion. Among these central players, macrophages have been one of the prime targets for the study of the link between circadian rhythms and inflammatory activities. Gene knockout experiments of various core circadian regulators have established that disruption of any core circadian regulators results in hyper- or hypoactivation of inflammatory responses by macrophages when challenged by lipopolysaccharide and bacteria. Although these stimulations are not directly linked to RA etiology, these findings serve as a foundation for further study by providing proof of principle. On the other hand, circadian regulation of osteoclasts, downstream effectors of macrophages, remain under-explored. Nonetheless, circadian expression of the inducers of osteoclastogenesis, such as TNFα, IL-1, and IL-6, as well as the knockout phenotypes of circadian regulators in osteoclasts suggest the significance of the circadian control of osteoclast activity in the pathogenesis of RA. More detailed mechanistic understanding of the circadian regulation of macrophages and osteoclasts in the afflicted joints could add novel local therapeutic options for RA.
Topics: Humans; Osteoclasts; Tumor Necrosis Factor-alpha; Interleukin-6; Arthritis, Rheumatoid; Macrophages; Cytokines; Interleukin-1
PubMed: 37569682
DOI: 10.3390/ijms241512307 -
Complementary Therapies in Medicine Oct 2023The COVID-19 pandemic increased psychological stress and decreased sleep quality, especially among young people. Aromatherapy alleviates psychological stress, and... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
The COVID-19 pandemic increased psychological stress and decreased sleep quality, especially among young people. Aromatherapy alleviates psychological stress, and bergamot essential oil helps improve depression. This study aimed to verify whether bergamot essential oil use alleviates psychological stress due to the COVID-19 pandemic and improves sleep quality and morning wakefulness.
DESIGN
A placebo-controlled, randomized, open-label, two-arm, two-period crossover trial.
INTERVENTIONS
Each intervention period was 1 week, with a 1-week washout period between the two periods. Participants used a bergamot or placebo spray before bedtime and upon awakening in each period.
MAIN OUTCOME MEASURES
The primary outcome measures were sleep quality and morning wakefulness, assessed using the Ogri-Shirakawa-Azumi sleep inventory MA version (OSA-MA). The secondary outcome measures were depression, anxiety, and stress, assessed using the Depression Anxiety Stress Scales-21 (DASS-21).
RESULTS
A total of 48 university students participated in the study. A significant improvement was observed in "sleepiness on rising," "refreshing on rising," and "sleep length" in the bergamot group. Additionally, a significant improvement was observed in depression, anxiety, and stress.
CONCLUSION
Using bergamot essential oil before bedtime helps relax the mind and body and provides sound sleep. It also improves mood and wakefulness when used upon awakening. Using aromatic essential oils is expected to relieve psychological stress and improve sleep quality and morning wakefulness.
Topics: Humans; Adolescent; Oils, Volatile; Sleep Quality; Cross-Over Studies; Pandemics; COVID-19; Stress, Psychological
PubMed: 37625623
DOI: 10.1016/j.ctim.2023.102976 -
Current Problems in Cardiology Jul 2023Sleep duration and chronotype have been associated with increased morbidity and mortality. We assessed for associations between sleep duration and chronotype on cardiac... (Review)
Review
Sleep duration and chronotype have been associated with increased morbidity and mortality. We assessed for associations between sleep duration and chronotype on cardiac structure and function. UK Biobank participants with CMR data and without known cardiovascular disease were included. Self-reported sleep duration was categorized as short (<7 h/d), normal (7-9 h/d) and long (>9 h/d). Self-reported chronotype was categories as "definitely morning" or "definitely evening." Analysis included 3903 middle-aged adults: 929 short, 2924 normal and 50 long sleepers; with 966 definitely-morning and 355 definitely-evening chronotypes. Long sleep was independently associated with lower left ventricular (LV) mass (-4.8%, P = 0.035), left atrial maximum volume (-8.1%, P = 0.041) and right ventricular (RV) end-diastolic volume (-4.8%, P = 0.038) compared to those with normal sleep duration. Evening chronotype was independently associated with lower LV end-diastolic volume (-2.4%, P = 0.021), RV end-diastolic volume (-3.6%, P = 0.0006), RV end systolic volume (-5.1%, P = 0.0009), RV stroke volume (RVSV -2.7%, P = 0.033), right atrial maximal volume (-4.3%, P = 0.011) and emptying fraction (+1.3%, P = 0.047) compared to morning chronotype. Sex interactions existed for sleep duration and chronotype and age interaction for chronotype even after considering potential confounders. In conclusion, longer sleep duration was independently associated with smaller LV mass, left atrial volume and RV volume. Evening chronotype was independently associated with smaller LV and RV and reduced RV function compared to morning chronotype. Sex interactions exist with cardiac remodeling most evident in males with long sleep duration and evening chronotype. Recommendations for sleep chronotype and duration may need to be individualized based on sex.
Topics: Male; Adult; Middle Aged; Humans; Sleep Duration; Chronotype; Biological Specimen Banks; Atrial Fibrillation; United Kingdom
PubMed: 36906161
DOI: 10.1016/j.cpcardiol.2023.101688 -
Arquivos Brasileiros de Cardiologia Oct 2023
Topics: Humans; Blood Pressure; Hypertension; Circadian Rhythm; Obesity; Blood Pressure Monitoring, Ambulatory
PubMed: 37937635
DOI: 10.36660/abc.20230608