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Bats are a group of mammals well known for forming dynamic social groups. Studies of bat social structures are often based upon the frequency at which bats occupy the same roosts because observing bats directly is not always possible. However, it is not always clear how closely bats occupying the same roost associate with each other, obscuring whether associations result from social relationships or factors such as shared preferences for roosts. Our goal was to determine if bats cohabitating buildings were also found together inside roosts by using anti‐collision technology for PIT tags, which enables simultaneous detection of multiple tags. We PIT‐tagged 293 female little brown myotis (Myotis lucifugus) and installed antennas within two buildings used as maternity roosts in Yellowstone National Park. Antennas were positioned at roost entryways to generate cohabitation networks and along regions of attic ceilings in each building to generate intraroost networks based on proximity of bats to each other. We found that intraroost and cohabitation networks of buildings were significantly correlated, with the same bats tending to be linked in both networks, but that bats cohabitating the same building often roosted apart, leading to differing assessments of social structure. Cohabitation rates implied that bats associate with a greater number of their roost‐mates than was supported by observations within the roost. This caused social networks built upon roost cohabitation rates to be denser, smaller in diameter, and contain nodes with higher average degree centrality. These results show that roost cohabitation does not reflect preference for roost‐mates in little brown myotis, as is often inferred from similar studies, and that social network analyses based on cohabitation may provide misleading results., Sociograms depicting connections among little brown myotis within a maternity colony in Yellowstone National Park. Social networks based upon the frequency at which pairs of bats cohabitate the same roost (Panels a and c) connect bats that rarely or never were found roosting along in the same location on attic ceilings (Panels b and d). This comparison shows that co‐roosting associations in little brown myotis do not reflect bats' preference for specific roost‐mates, as is often interpreted in similar studies.

Summary Interventions that delay ageing mobilize mechanisms that protect and repair cellular components1–3, but it is unknown how these interventions might slow the functional decline of extracellular matrices4,5, which are also damaged during ageing6,7. Reduced Insulin/IGF-1 signalling (rIIS) extends lifespan across the evolutionary spectrum, and in juvenile C. elegans also allows the transcription factor DAF-16/FOXO to induce development into dauer, a diapause that withstands harsh conditions (Supplementary Discussion)1,2. It has been suggested that rIIS delays C. elegans ageing through activation of dauer-related processes during adulthood2,8,9, but some rIIS conditions confer robust lifespan extension unaccompanied by any dauer-like traits1,10,11. Here we show that rIIS can promote C. elegans longevity through an program that is genetically distinct from the dauer pathway, and requires the Nrf (NF-E2-related factor) ortholog SKN-1 acting in parallel to DAF-16. SKN-1 is inhibited by IIS and has been broadly implicated in longevity12–14, but is rendered dispensable for rIIS lifespan extension by even mild activity of dauer-related processes. When IIS is decreased under conditions that do not induce dauer traits, SKN-1 most prominently increases expression of collagens and other extracellular matrix (ECM) genes. Diverse genetic, nutritional, and pharmacological pro-longevity interventions delay an age-related decline in collagen expression. These collagens mediate adulthood ECM remodelling, and are needed for ageing to be delayed by interventions that do not involve dauer traits. By genetically delineating a dauer-independent rIIS ageing pathway, our results show that IIS controls a broad set of protective mechanisms during C. elegans adulthood, and may facilitate elucidation of processes of general importance for longevity. The importance of collagen production in diverse anti-ageing interventions implies that ECM remodelling is a generally essential signature of longevity assurance, and that agents promoting ECM youthfulness may have systemic benefit.

Als mögliche Kandidatengene, die für eine Opiatabhängigkeit prädisponieren, gelten das Dopaminrezeptor D3-Gen und das brain-derived neurotrophic factor-Gen. Ziel dieser Arbeit war es zu untersuchen, ob der Ser9Gly-Polymorphismus des DRD3-Gens und der Val66Met-Polymorphismus des BDNF-Gens oder deren mögliche Wechselwirkung als genetischer Prädiktor für die Entwicklung und Aufrechterhaltung einer Opiatabhängigkeit anzusehen sind. Die vorliegende Arbeit stellt die bisher größte Assoziations- und Kopplungsstudie dieser Polymorphismen zur Opiatabhängigkeit eines ethnisch homogenen, deutschen Studienkollektivs dar. Allel- und Genotypverteilung wurden mittels molekularbiologischer Methoden ermittelt und unter Verwendung statistischer Standardverfahren ausgewertet. Die Auswertung zeigte keine erhöhte homozygote Allel- bzw. Genotypverteilung bei Opiatabhängigen im Vergleich zur gesunden Kontrollgruppe. Ebenso wenig konnte eine Wechselwirkung der beiden Genpolymorphismen festgestellt werden.