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Prevalence of sexual aggression victimization and perpetration in a German university student sample
(2021)
This study examined the prevalence of sexual aggression perpetration and victimization in a sample of 1,172 students (755 female, 417 male) from four universities in Germany. All participants were asked about both victimization by, and perpetration of, sexual aggression since the age of 14 years, using the Sexual Aggression and Victimization Scale (SAV-S). Prevalence rates were established for different coercive strategies, sexual acts, and victim-perpetrator relationships. Both same-sex and opposite-sex victim-perpetrator constellations were examined. The overall victimization rate was 62.1% for women and 37.5% for men. The overall perpetration rate was 17.7% for men and 9.4% for women. Prevalence rates of both victimization and perpetration were higher for participants who had sexual contacts with both opposite-sex and same-sex partners than for participants with exclusively opposite-sex partners. Significant overlap was found between victim and perpetrator status for men and women as well as for participants with only opposite-sex and both opposite-sex and same-sex partners. A disparity between (higher) victimization and (lower) perpetration reports was found for both men and women, suggesting a general underreporting of perpetration rather than a gendered explanation in terms of social desirability or the perception of consent cues. The findings are placed in the international research literature on the prevalence of sexual aggression before and after the #metoo campaign, and their implications for prevention efforts are discussed.
Foraging is risky and involves balancing the benefits of resource acquisition with costs of predation. Optimal foraging theory predicts where, when and how long to forage in a given spatiotemporal distribution of risks and resources. However, significant variation in foraging behaviour and resource exploitation remain unexplained. Using single foragers in artificial landscapes of perceived risks and resources with diminishing returns, we aimed to test whether foraging behaviour and resource exploitation are adjusted to risk level, vary with risk during different components of foraging, and (co)vary among individuals. We quantified foraging behaviour and resource exploitation for 21 common voles (Microtus arvalis). By manipulating ground cover, we created simple landscapes of two food patches varying in perceived risk during feeding in a patch and/or while travelling between patches. Foraging of individuals was variable and adjusted to risk level and type. High risk during feeding reduced feeding duration and food consumption more strongly than risk while travelling. Risk during travelling modified the risk effects of feeding for changes between patches and resulting evenness of resource exploitation. Across risk conditions individuals differed consistently in when and how long they exploited resources and exposed themselves to risk. These among-individual differences in foraging behaviour were associated with consistent patterns of resource exploitation. Thus, different strategies in foraging-under-risk ultimately lead to unequal payoffs and might affect lower trophic levels in food webs. Inter-individual differences in foraging behaviour, i.e. foraging personalities, are an integral part of foraging behaviour and need to be fully integrated into optimal foraging theory.
Advanced non-viral gene delivery experiments often require co-delivery of multiple nucleic acids. Therefore, the availability of reliable and robust co-transfection methods and defined selection criteria for their use in, e.g., expression of multimeric proteins or mixed RNA/DNA delivery is of utmost importance. Here, we investigated different co- and successive transfection approaches, with particular focus on in vitro transcribed messenger RNA (IVT-mRNA). Expression levels and patterns of two fluorescent protein reporters were determined, using different IVT-mRNA doses, carriers, and cell types. Quantitative parameters determining the efficiency of co-delivery were analyzed for IVT-mRNAs premixed before nanocarrier formation (integrated co-transfection) and when simultaneously transfecting cells with separately formed nanocarriers (parallel co-transfection), which resulted in a much higher level of expression heterogeneity for the two reporters. Successive delivery of mRNA revealed a lower transfection efficiency in the second transfection round. All these differences proved to be more pronounced for low mRNA doses. Concurrent delivery of siRNA with mRNA also indicated the highest co-transfection efficiency for integrated method. However, the maximum efficacy was shown for successive delivery, due to the kinetically different peak output for the two discretely operating entities. Our findings provide guidance for selection of the co-delivery method best suited to accommodate experimental requirements, highlighting in particular the nucleic acid dose-response dependence on co-delivery on the single-cell level.
Die aktuelle COVID-19-Pandemie zeigt deutlich, wie sich Infektionskrankheiten weltweit verbreiten können. Neben Viruserkrankungen breiten sich auch multiresistente bakterielle Erreger weltweit aus. Dementsprechend besteht ein hoher Bedarf, durch frühzeitige Erkennung Erkrankte zu finden und Infektionswege zu unterbrechen.
Herkömmliche kulturelle Verfahren benötigen minimalinvasive bzw. invasive Proben und dauern für Screeningmaßnahmen zu lange. Deshalb werden schnelle, nichtinvasive Verfahren benötigt.
Im klassischen Griechenland verließen sich die Ärzte unter anderem auf ihren Geruchssinn, um Infektionen und andere Krankheiten zu differenzieren. Diese charakteristischen Gerüche sind flüchtige organische Substanzen (VOC), die im Rahmen des Metabolismus eines Organismus entstehen. Tiere, die einen besseren Geruchssinn haben, werden trainiert, bestimmte Krankheitserreger am Geruch zu unterscheiden. Allerdings ist der Einsatz von Tieren im klinischen Alltag nicht praktikabel. Es bietet sich an, auf technischem Weg diese VOCs zu analysieren.
Ein technisches Verfahren, diese VOCs zu unterscheiden, ist die Ionenmobilitätsspektrometrie gekoppelt mit einer multikapillaren Gaschromatographiesäule (MCC-IMS). Hier zeigte sich, dass es sich bei dem Verfahren um eine schnelle, sensitive und verlässliche Methode handelt.
Es ist bekannt, dass verschiedene Bakterien aufgrund des Metabolismus unterschiedliche VOCs und damit eigene spezifische Gerüche produzieren. Im ersten Schritt dieser Arbeit konnte gezeigt werden, dass die verschiedenen Bakterien in-vitro nach einer kurzen Inkubationszeitzeit von 90 Minuten anhand der VOCs differenziert werden können. Hier konnte analog zur Diagnose in biochemischen Testreihen eine hierarchische Klassifikation der Bakterien erfolgen.
Im Gegensatz zu Bakterien haben Viren keinen eigenen Stoffwechsel. Ob virusinfizierte Zellen andere VOCs als nicht-infizierte Zellen freisetzen, wurde an Zellkulturen überprüft. Hier konnte gezeigt werden, dass sich die Fingerprints der VOCs in Zellkulturen infizierter Zellen mit Respiratorischen Synzytial-Viren (RSV) von nicht-infizierten Zellen unterscheiden.
Virusinfektionen im intakten Organismus unterscheiden sich von den Zellkulturen dadurch, dass hier neben Veränderungen im Zellstoffwechsel auch durch Abwehrmechanismen VOCs freigesetzt werden können.
Zur Überprüfung, inwiefern sich Infektionen im intakten Organismus ebenfalls anhand VOCs unterscheiden lassen, wurde bei Patienten mit und ohne Nachweis einer Influenza A Infektion als auch bei Patienten mit Verdacht auf SARS-CoV-2 (Schweres-akutes-Atemwegssyndrom-Coronavirus Typ 2) Infektion die Atemluft untersucht. Sowohl Influenza-infizierte als auch SARS-CoV-2 infizierte Patienten konnten untereinander und von nicht-infizierten Patienten mittels MCC-IMS Analyse der Atemluft unterschieden werden.
Zusammenfassend erbringt die MCC-IMS ermutigende Resultate in der schnellen nichtinvasiven Erkennung von Infektionen sowohl in vitro als auch in vivo.
Sequelae of prematurity triggered by oxidative stress and free radical-mediated tissue damage have coined the term “oxygen radical disease of prematurity”. Caffeine, a potent free radical scavenger and adenosine receptor antagonist, reduces rates of brain damage in preterm infants. In the present study, we investigated the effects of caffeine on oxidative stress markers, anti-oxidative response, inflammation, redox-sensitive transcription factors, apoptosis, and extracellular matrix following the induction of hyperoxia in neonatal rats. The brain of a rat pups at postnatal Day 6 (P6) corresponds to that of a human fetal brain at 28–32 weeks gestation and the neonatal rat is an ideal model in which to investigate effects of oxidative stress and neuroprotection of caffeine on the developing brain. Six-day-old Wistar rats were pre-treated with caffeine and exposed to 80% oxygen for 24 and 48 h. Caffeine reduced oxidative stress marker (heme oxygenase-1, lipid peroxidation, hydrogen peroxide, and glutamate-cysteine ligase catalytic subunit (GCLC)), promoted anti-oxidative response (superoxide dismutase, peroxiredoxin 1, and sulfiredoxin 1), down-regulated pro-inflammatory cytokines, modulated redox-sensitive transcription factor expression (Nrf2/Keap1, and NFκB), reduced pro-apoptotic effectors (poly (ADP-ribose) polymerase-1 (PARP-1), apoptosis inducing factor (AIF), and caspase-3), and diminished extracellular matrix degeneration (matrix metalloproteinases (MMP) 2, and inhibitor of metalloproteinase (TIMP) 1/2). Our study affirms that caffeine is a pleiotropic neuroprotective drug in the developing brain due to its anti-oxidant, anti-inflammatory, and anti-apoptotic properties.
Plant cell biology
(2021)
PIN-FORMED (PIN) polar protein localization directs transport of the growth and developmental regulator auxin in plants. Once established after cytokinesis, PIN polarity requires maintenance. Now, direct interactions between PIN, MAB4/MEL and PID proteins suggest self-reinforced maintenance of PIN polarity through limiting lateral diffusion.
We expressedDictyosteliumlamin (NE81) lacking both a functional nuclear localization signal and a CAAX-box for C-terminal lipid modification. This lamin mutant assembled into supramolecular, three-dimensional clusters in the cytosol that disassembled at the onset of mitosis and re-assembled in late telophase, thus mimicking the behavior of the endogenous protein. As disassembly is regulated by CDK1-mediated phosphorylation at serine 122, we generated a phosphomimetic S122E mutant called GFP-NE81-S122E-Delta NLS Delta CLIM. Surprisingly, during imaging, the fusion protein assembled into cytosolic clusters, similar to the protein lacking the phosphomimetic mutation. Clusters disassembled again in the darkness. Assembly could be induced with blue but not green or near ultraviolet light, and it was independent of the fusion tag. Assembly similarly occurred upon cell flattening. Earlier reports and own observations suggested that both blue light and cell flattening could result in a decrease of intracellular pH. Indeed, keeping the cells at low pH also reversibly induced cluster formation. Our results indicate that lamin assembly can be induced by various stress factors and that these are transduced via intracellular acidification. Although these effects have been shown in a phosphomimetic CDK1 mutant of theDictyosteliumlamin, they are likely relevant also for wild-type lamin.
Sustained glacier melt in the Himalayas has gradually spawned more than 5,000 glacier lakes that are dammed by potentially unstable moraines. When such dams break, glacier lake outburst floods (GLOFs) can cause catastrophic societal and geomorphic impacts. We present a robust probabilistic estimate of average GLOFs return periods in the Himalayan region, drawing on 5.4 billion simulations. We find that the 100-y outburst flood has an average volume of 33.5(+3.7)/(-3.7) x 10(6) m(3) (posterior mean and 95% highest density interval [HDI]) with a peak discharge of 15,600(+2.000)/(-1,800) m(3).S-1. Our estimated GLOF hazard is tied to the rate of historic lake outbursts and the number of present lakes, which both are highest in the Eastern Himalayas. There, the estimated 100-y GLOF discharge (similar to 14,500 m(3).s(-1)) is more than 3 times that of the adjacent Nyainqentanglha Mountains, and at least an order of magnitude higher than in the Hindu Kush, Karakoram, and Western Himalayas. The GLOF hazard may increase in these regions that currently have large glaciers, but few lakes, if future projected ice loss generates more unstable moraine-dammed lakes than we recognize today. Flood peaks from GLOFs mostly attenuate within Himalayan headwaters, but can rival monsoon-fed discharges in major rivers hundreds to thousands of kilometers downstream. Projections of future hazard from meteorological floods need to account for the extreme runoffs during lake outbursts, given the increasing trends in population, infrastructure, and hydropower projects in Himalayan headwaters.
The shape of a defense-growth trade-off governs seasonal trait dynamics in natural phytoplankton
(2020)
Theory predicts that trade-offs, quantifying costs of functional trait adjustments, crucially affect community trait adaptation to altered environmental conditions, but empirical verification is scarce. We evaluated trait dynamics (antipredator defense, maximum growth rate, and phosphate affinity) of a lake phytoplankton community in a seasonally changing environment, using literature trait data and 21 years of species-resolved high-frequency biomass measurements. The trait data indicated a concave defense-growth trade-off, promoting fast-growing species with intermediate defense. With seasonally increasing grazing pressure, the community shifted toward higher defense levels at the cost of lower growth rates along the trade-off curve, while phosphate affinity explained some deviations from it. We discuss how low fitness differences of species, inferred from model simulations, in concert with stabilizing mechanisms, e.g., arising from further trait dimensions, may lead to the observed phytoplankton diversity. In conclusion, quantifying trade-offs is key for predictions of community trait adaptation and biodiversity under environmental change.
