Poultry and Eggs
Christopher Cumo in Ancestral Diets and Nutrition, 2020
By observing birds, prehistoric peoples tracked their habits and detected their vulnerability in spring during molting and nesting and in autumn when summer engorgement fattened them.12 During the Mesolithic Period (9000–7000 BCE), humans reconnoitered wetlands for several species. For example, Danes hunted mallards (Anas platyrhynchos), swans (Cygnus species), grebes (species in the family Podicipedidae), Eurasian coots (Fulica atra), cormorants (species in the family Phalacrocoracidae), and gulls (Larus species). Near the North and Baltic Seas, hunters targeted Eurasian cranes (Grus grus), swans, cormorants, and sea eagles (Haliaeetus species). Mesolithic Germans consumed mallards. To the east, Baltic, Polish, and Russian wetlands yielded numerous bird bones as dietary evidence. Eighty-nine percent of bones from a Mesolithic site along Estonia’s Narva River are waterfowl, chiefly mallards.13 Likely wielding slings, Iron Age (800 BCE–42 CE) Britons near what is today Somerset, England, also hunted mallards.
Evidence for a Thymus-Pineal Axis
Nate F. Cardarelli in The Thymus in Health and Senescence, 2019
In 1934 Wigglesworth demonstrated that molting hormone is secreted by the corpus allatum gland in the insect head.131 Decapitation prevented molting, whereas blood from a premolt intact insect injected into a headless nymph will induce moulting. Fraenkel’s work was partially confirming.132 In a 1936 review article, Wigglesworth notes that the corpora allata (CA) seem to produce both a molting hormone and a molt inhibiting hormone.133 For a few years there was controversy as to whether molting was controlled by the CA or by the prothoracic gland.134,135 Piepho showed in 1942 that both glands were needed, a secretion from the brain causing a response (secretion) from the prothoracic gland (PT).136 By 1947 it was well established that a brain factor activates the PT to cause metamorphosis into the adult insect.137 The secretory factors were not species specific. By 1949 Williams can confidently conclude that there are three essential components involved in maturation of the insect, brain, CA, and PT.126 Pupation and adult development is under the control of a brain hormone that stimulates the PT, which then releases a growth and differentiation hormone.138 Pupal diapause is thus a state of endocrine deficiency as the brain does not release its tropic hormone. The CA plays no role in adult development or pupation, but rather releases a conservative factor that interacts with the PT.
Learning through epistemic practices in professional work
Tara Fenwick, Monika Nerland in Reconceptualising Professional Learning, 2014
In our studies, we also observed how the methodological principles of agile software development could turn into epistemic objects themselves. Several engineers were concerned with understanding and applying these principles in their everyday work. One of them described the current situation as one of ‘moulting’, where the shift in methods of working generated significant attention towards managing the work process. To create a line of orderliness in the process, they needed to explore the meanings of the agile principles as well as to materialize these principles in their work context. This took, for instance, the form of creating new platforms for knowledge sharing, experimenting with new forms of collaboration by training programmers to align their ways of writing programming code with each other and developing shared routines for integrating testing in the development process. In these processes, different suggestions and ways of doing programming are explored, assessed and aligned. Although there is a relatively strong request to adjust and align practices within the team, every participant is also encouraged to bring about creative ideas and solutions. As one engineer put it, ‘everybody should be creative, however it has to be some defined frames. You cannot just float out … everybody needs to adjust and work in about the same manner’.
Advances in thermal physiology of diving marine mammals: The dual role of peripheral perfusion
Published in Temperature, 2022
Arina B. Favilla, Markus Horning, Daniel P. Costa
Future work should address other conflicting physiological demands that require peripheral perfusion and their interactions with thermoregulation. For instance, molting is a necessary phenomenon that requires perfusion of the skin to replace old skin and fur. The form and phenology of molting vary widely, from annual catastrophic molting to continuous gradual molting. It often depends on whether animals can find thermal refugia to minimize the energetic costs of increased heat loss associated with skin perfusion [136–139]. Similarly, wound healing requires perfusion of the injured site, potentially leading to a tradeoff in short-term energetic costs and long-term health and survival. Haul-out periods for amphibious species, or seasonal residency at warmer latitudes for long-distance migrators, allow for temporal separation of these physiological demands that would otherwise increase thermoregulatory costs. Finally, unlike fur, blubber is a living tissue that serves as an energy store, and depositing or metabolizing lipid stores also requires perfusion of this layer [32,140,141]. Thus, in addition to the dual role associated with thermoregulation and diving that was the primary focus of this review, peripheral perfusion is critical for many other physiological processes. How these conflicting demands interact with each other warrants further investigation.
Elucidation of molecular expression associated with abnormal development and sterility caused by electron beam irradiation in Spodoptera litura (F.) (Lepidoptera: Noctuidae)
Published in International Journal of Radiation Biology, 2019
Hyun-Na Koo, Seung-Hwan Yun, HyunKyung Kim, Gil-Hah Kim
Protein expression patterns were analyzed by SDS-PAGE to investigate the levels of hemolymph proteins after electron beam irradiation. The results showed that the level of storage protein (approximately 70 kDa) decreased as the electron beam dose increased. Storage protein is one of the major proteins of larval hemolymph (Pan and Telfer 2001; Chandrasekar, Jae et al. 2008; Chandrasekar, Sumithra et al. 2008). It is also involved in molting, metamorphosis, and reproduction and is affected by hormone, sex, and nutritional status. It is synthesized in the fat body and released into the hemolymph only during the larval stage, in which feeding is possible (Liu et al. 2009; Chandrasekar 2012). The low levels of hemolymph protein after electron beam irradiation might have been affected by the reduced feeding. In addition, as the synthesis of storage protein is influenced by hormones, it is presumed that the differences in storage protein level from the control level were due to a hormonal disturbance caused by electron beam irradiation. However, there was no evidence that the effect of electron beam irradiation on larval hemolymph protein impacted the growth characteristics of S. litura. Schloter (1985) stated that the decrease in hemolymph protein, including storage protein, might have inhibited the metamorphosis of the insect, Epilachna varivestis after azadirachtin injection. In the present study, our data indicated that the reduction in hemolymph protein might have caused deformity in S. litura.
Comparative transcriptome analysis reveals the impact of the daily rhythm on the hemolymph of the Chinese mitten crab (Eriocheir sinensis)
Published in Chronobiology International, 2022
Changyue Yu, Baoli Zhang, Zhiyuan Zhang, Simiao Wang, Tingyu Wei, Lisong Li, Yingying Zhao, Hua Wei, Yingdong Li
Consistent with the functional enrichment analysis of DEGs, some of the genes related to the molting process were upregulated at 18:00 h, indicating that E. sinensis may molt at night. In crustacean decapods, the exoskeleton is the main component of chitin, and its metabolism is the most critical process of growth and development (Hans and Lars 2003). Here, genes related to exoskeleton metabolism, such as those for chitinases, chitin deacetylase, and chitin synthase, were found in clusters 1, 2, and 3 in the transcriptional trend map under the daily cycle. However, the gene expression trends of these three clusters were not the same, and this may be because chitin is laid down daily in a molt rhythm, resulting in daily cycles that are numerically related to the molting time (Abehsera et al. 2014). However, the time of molting can be influenced by the day–night process (Robert and Gabriele 2013). The present findings showed that the molting-related gene encoding farnesoic acid O-methyltransferase (cluster 9) has higher expression levels at midnight and relatively low expression level during the daytime. Furthermore, the retinol metabolism and steroid hormone biosynthesis pathways were significantly upregulated at 24:00 h compared with those in the 12:00 h group. However, previous research has confirmed that the molting process of crustaceans occurs mainly at night (Iribarne et al. 2009). From these results, we speculate that E. sinensis molts mainly at night, consistent with the findings of a previous transcriptomic study of its eyestalk (Li et al. 2019).
Related Knowledge Centers
- Alfalfa
- Ecdysis
- Epidermis
- Exoskeleton
- Thermoregulation
- Fur
- Hair
- Wool
- Wing
- Feather-Plucking