Therapeutics of Artemisia annua
Tariq Aftab, M. Naeem, M. Masroor, A. Khan in Artemisia annua, 2017
Non-glandular, “T” shaped, trichomes are also present along with 10-celled biseriate glandular trichome on leaves, stem, and inflorescence. The morphology and origin of the trichomes have been described in detail for leaves (Duke and Paul,1993) and capitula (Ferreira and Janick, 1995) using light and/or scanning electron microscopy. It is a short day plant, very responsive to photoperiodic stimulus. The critical photoperiod is reported to be about 13.5 daylight hours, but there is a possibility of photoperiod × temperature interaction. The plants flower in early September with the production of mature seeds in October (Janick, 1995). Nuclear DNA content and other karyological characters in the population of A. annua were studied by Torrell and Valles (2001). In their study, the DNA per haploid genome was 1.75pg, the total karyotypic length was 19.58 μm, and the total haploid chromosome set length was 9.74 μm. They also reported that the annual species A. annua, showed the lowest amount of DNA as compared to the other species. It has approximately 35% lower C value than those of the perennial species.
Sexual Differentiation of a Neuromuscular System
Akira Matsumoto in Sexual Differentiation of the Brain, 2017
The activational effect of androgen on SNB morphology is not limited to experimental hormone manipulations: Forger and Breedlove62 showed that plasticity of SNB motoneurons can be correlated with natural fluctuations in circulating androgens. Outside their breeding season, the reproductive system of the male white-footed mouse regresses. Photoperiods are the most predictable signal of seasonal change and can be used to induce these alterations in reproductive function in the laboratory. Animals kept in short days exhibit gonadal involution and a reduction in seminal vesicle and BC/LA muscle weight in comparison with animals kept in long days. Forger and Breedlove62 found that males kept in short days also have significantly smaller SNB somata, nuclei, and dendrites than do males kept in long days. In keeping with the effect found in rats by Kurz et al.,56 SNB motoneurons in white-footed mice that were castrated and given T replacement for 4 weeks had longer dendrites (22% more) than castrates that received no T replacement. Thus, in this species, the size of SNB dendritic arbor, somata, and nuclei is under androgenic control and is contingent upon naturally fluctuating T levels.
Eating Disorders and Treatment
Emily Crews Splane, Neil E. Rowland, Anaya Mitra in Psychology of Eating, 2019
Unfortunately for the animal model perspective, humans are not photoperiodic with regard to mating or breeding behavior, but one could argue that some individuals such as those prone to seasonal affective disorder may exhibit some elements of photoperiodism. One established laboratory model that does not involve photoperiodism is called activity-based anorexia (ABA; Epling, Pierce & Stefan, 1983). In this protocol, animals (usually rats or mice) are given food for a restricted time each day – often two to four hours. Most species are able to adapt to this type of schedule quite well; although they don’t eat as much as they would with 24-hour access, they do eat more than enough to maintain a healthy body weight. In fact, this type of time-restricted feeding regimen is common in zoos and for domestic pets. In ABA, the animals are additionally provided with a running wheel. As they lose weight, they tend to run more and so expend more energy, but their food intake does not rise commensurately (and may in fact be suppressed a bit). As a result, they are trapped in a spiral of progressively more negative energy balance and usually have to be removed from the experiment for humane reasons when weight loss exceeds a threshold (e.g., 15%).
Perinatal photoperiod associations with diabetes and chronotype prevalence in a cross-sectional study of the UK Biobank
Published in Chronobiology International, 2021
Philip Lewis, Peter Morfeld, Judith Mohren, Martin Hellmich, Thomas C. Erren
A previous epidemiological study indicated possible differential “dose” responses (Lewis et al. 2020a). Furthermore, extreme short photoperiods (ESPs, <8 h) are potentially confounded by unmeasured artificial light that may have a more dominant circadian role when daylight is extremely short. Similarly, extreme long photoperiods (ELPs, >16 h) are potentially confounded by measures taken against light during biological nights. Thus, we distinguish in analyses between individuals who experience one or more ESPs or ELPs, and non-extreme photoperiods (NEPs) to consider a varying degree of unmeasured confounding or possible differential “dose” response. In other words, we defined three groups based on photoperiods experienced in the 3rd trimester and 3 months post birth time windows: (1) NEP (i.e., NEPs-only within the time window of interest), (2) ESP (individuals who experience at least 1 ESP in the time window of interest), and (3) ELP (individuals who experience at least 1 ELP in the time window of interest).
Photoperiodic adaptation of aanat and clock gene expression in seasonal populations of Daphnia pulex
Published in Chronobiology International, 2023
Anke Schwarzenberger, Patrick Bartolin, Alexander Wacker
Clonal succession of Daphnia over time and seasons has often been observed in lakes and ponds (Pfrender and Lynch 2000; Spaak 1996). This succession can be a result of seasonal changes in temperature and population density (Carvalho and Crisp 1987), anoxia (Geedey et al. 1996), the presence of vertebrate and invertebrate predators (Stibor and Lampert 2000), putatively the occurrence of protease-inhibitor producing cyanobacteria (Schwarzenberger et al. 2013), etc. One of the most pronounced seasonal changes is the change from short to long photoperiods and vice versa. It has been demonstrated that a marine Antarctic crustacean (i.e. krill) shows adaptations to seasonal photoperiod that are timed by adjustment of endogenous clock gene expression (Piccolin et al. 2018a, 2018b). Similarly, a marine copepod has been demonstrated to differ in clock gene expression in the active (long photoperiod in summer) in comparison to the diapause phase (short photoperiod in winter; Häfker et al. 2018). To our knowledge, a seasonal adaptation of the endogenous clock has not been investigated in other crustaceans, e.g. the freshwater crustacean Daphnia.
Melatonin-stimulated biosynthesis of anti-microbial ZnONPs by enhancing bio-reductive prospective in callus cultures of Catharanthus roseus var. Alba
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Hafiza Rida Riaz, Syed Salman Hashmi, Tariq Khan, Christophe Hano, Nathalie Giglioli-Guivarc’h, Bilal Haider Abbasi
Melatonin (N-acetyl-5-tryptamine) is a PGR and belongs to the family indole-amines [24,25]. It governs the growth of explants, shoots and roots. It helps in activation of rhizogenesis and delays leaf senescence [26]. Melatonin, having the natural antioxidant capacity, plays an important role during abiotic stress such as heat, salinity, cold, drought, UV-radiation, herbicides and chemical pollutants [27,28]. Melatonin proved to be efficient in inducing defence either local or systematic against photo-oxidative stress [29]. It plays important role in photoperiodism such as flowering [30]. Melatonin has been reported for enhanced Ag-NPs synthesis by improving bio-reductive potential [19]. In the present work, melatonin is investigated for enhanced ZnONPs synthesis and anti-bacterial efficacy by improving phytochemical constituents when applied exogenously in callus cultures of C. roseus. Further, melatonin is compared with other PGRs (NAA, Kin, TDZ and 2,4-D) for its potential to improve the phytochemical status of C. roseus callus cultures.
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