Orchestration of gene expression across the seasons : Hypothalamic gene expression in natural photoperiod throughout the year in the Siberian hamster

Acknowledgements Funding for work in the laboratory of PB was supported by Scottish Government Rural and Environment Science and Analytical Services Division, BBSRC (grant BB/M001504/1), British Society for Neuroendocrinology (research visit grant to IP). Work in the laboratory of SS was supported by a grant from the DFG (Ste 331/8-1). We thank Siegried Hilken, Marianne Brüning, Dr. Esther Lipokatic-Takacs and Dr. Frank Scherbarth at UVMH for technical assistance. We thank Graham Horgan of Bioinformatics, Statistics Scotland for assistance with some of statistical tests.Peer reviewedPublisher PD

Potential effects of optical solar sail degredation on trajectory design

The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions

In-situ Magnesium Diboride Superconducting Thin Films grown by Pulsed Laser Deposition

Superconducting thin films of MgB2 were deposited by Pulsed Laser Deposition on magnesium oxide and sapphire substrates. Samples grown at 450C in an argon buffer pressure of about 10-2 mbar by using a magnesium enriched target resulted to be superconducting with a transition temperature of about 25 K. Film deposited from a MgB2 sintered pellet target in ultra high vacuum conditions showed poor metallic or weak semiconducting behavior and they became superconducting only after an ex-situ annealing in Mg vapor atmosphere. Up to now, no difference in the superconducting properties of the films obtained by these two procedures has been evidenced.Comment: 10 pages, 4 figure

Short Photoperiod-Dependent Enrichment of <i>Akkermansia spec</i>. as the Major Change in the Intestinal Microbiome of Djungarian Hamsters (<i>Phodopus sungorus</i>)

The Djungarian hamster (Phodopus sungorus) is a prominent model organism for seasonal acclimatization, showing drastic whole-body physiological adjustments to an energetically challenging environment, which are considered to also involve the gut microbiome. Fecal samples of hamsters in long photoperiod and again after twelve weeks in short photoperiod were analyzed by 16S-rRNA sequencing to evaluate seasonal changes in the respective gut microbiomes. In both photoperiods, the overall composition was stable in the major superordinate phyla of the microbiota, with distinct and delicate changes of abundance in phyla representing each Akkermansia muciniphila is a prominent gut microbiome inhabitant well described as important in the health context of animals and humans, including neurodegenerative diseases and obesity. Since diet was not changed, Akkermansia enrichment appears to be a direct consequence of short photoperiod acclimation. Future research will investigate whether the Djungarian hamster intestinal microbiome is responsible for or responsive to seasonal acclimation, focusing on probiotic supplementation

MDPI-IJMS_Kissmann et al. 2023

item provides body mass, food, and fur index data of Djungarian hamsters in summer-like long photoperiod and during twelve weeks of acclimation to winter-like short photoperiod furthermore, 16S RNA Illumina sequence counts of intestinal microbiome taxa from pooled long and short photoperiod fecal samples are listed </ul

Seasonal and fasting induced changes in iron metabolism in Djungarian hamsters.

Djungarian hamsters are small rodents that show pronounced physiological acclimations in response to changes in photoperiod, and unfavorable environmental conditions such as reduced food availability and low external temperature. These include substantial adjustments, such as severe body weight loss and the use of daily torpor. Torpor is a state of decreased physiological activity in eutherms, usually marked by low metabolic rate and a reduced body temperature. In this study, we investigated the effects of photoperiodic acclimation and food deprivation on systemic iron metabolism in Djungarian hamsters. Our study illustrates the association between liver iron levels and the incidence of torpor expression during the course of the experiment. Moreover, we show that both, acclimation to short photoperiods and long-term food restriction, associated with iron sequestration in the liver. This effect was accompanied with hypoferremia and mild reduction in the expression of principal iron-hormone, hepcidin. In addition to iron, the levels of manganese, selenium, and zinc were increased in the liver of hamsters under food restriction. These findings may be important factors for regulating physiological processes in hamsters, since iron and other trace elements are essential for many metabolic and physiological processes

Mitochondrial RNA stimulates beige adipocyte development

Here we provide image source files (histology, immunofluorescence, vital staining of mitochondria, etc.), qPCR measurement files, ELISA measurement files and their metafiles, as well as indirect calorimetry acqusition files for data/images published in the accompanied article. Replicate experiments are stored in Figshare, and are accessible upon request. Further data have been deposited in GEO and Flow Repository