Search

Abstract Curved cell shapes are widespread among bacteria and important for cellular motility, virulence and fitness. However, the underlying morphogenetic mechanisms are still incompletely understood. Here, we identify an outer-membrane protein complex that promotes cell curvature in the photosynthetic species Rhodospirillum rubrum. We show that the R. rubrum porins Por39 and Por41 form a helical ribbon-like structure at the outer curve of the cell that recruits the peptidoglycan-binding lipoprotein PapS, with PapS inactivation, porin delocalization or disruption of the porin-PapS interface resulting in cell straightening. We further demonstrate that porin-PapS assemblies act as molecular cages that entrap the cell elongation machinery, thus biasing cell growth towards the outer curve. These findings reveal a mechanistically distinct morphogenetic module mediating bacterial cell shape. Moreover, they uncover an unprecedented role of outer-membrane protein patterning in the spatial control of intracellular processes, adding an important facet to the repertoire of regulatory mechanisms in bacterial cell biology.

High temperatures that prevail at sun-exposed sites such as heaths, depressions, or on slopes, increase the risk of desiccation for rove beetles (Staphylinidae). Therefore, atmospheric and sub-atmospheric humidity determine the microclimates and thus habitat preference and activity of xerothermophilous species. In the nature reserve Marienfließ, a heathland in the south of Mecklenburg-Western Pomerania, Northeast German Lowlands, air temperature and humidity were recorded year-round along a transect at 10 sites, i.e. where the vegetation was more dense and more humid than where the vegetation was sparse and it was drier, using data loggers placed in the litter layer that recorded the conditions every 30 min in 2021. Monthly visits were made to determine the biomass of vegetation, soil and litter properties, edaphic rove beetle fauna and total abundance and and that of individual species at 1 m2 sites. Statistical analysis of 365 diurnal cycles per site, with pronounced amplitude in air temperature and humidity, clearly delineated the cooler and more humid sites from warmer and drier ones. Between 10 and 22 of the 30 xerothermophilous species (73.3%), such as, e.g. Quedius persimilis Mulsant & Rey, 1876, Xantholinus gallicus Coiffait, 1956, Cousya longitarsis (Thomson, 1867) and Euaesthetus superlatus Peyerimhoff, 1937, were recorded only at the cooler and moist sites on the heath. Comparison of the abundances and distribution of species revealed that the xerothermophilous heath-dwelling and desiccation-prone species prefer rather constant environmental conditions, i.e. niches in cool and moist habitats on warm and dry heathland.

Background: For patients experiencing ischemic stroke despite receiving therapy with direct oral anticoagulants (DOAC) and without endovascular treatment options, therapeutic prospects are currently dismal. Current guidelines recommend intravenous thrombolysis (IVT) only for patients who have received DOAC in very restricted settings, as an increased risk of bleeding is suspected. However, recent retrospective observational studies suggest that IVT is safe despite DOAC pretreatment. Objectives: To provide further evidence that IVT despite previous DOAC treatment is not associated with an increased risk of bleeding. Design: Observational retrospective study. Methods: Demographic, clinical, and radiological data of patients who received IVT (+/− endovascular thrombectomy) despite DOAC pretreatment between June 2021 and January 2024 were analyzed using descriptive statistics, including DOAC plasma concentration at admission. Secondary intracranial hemorrhages and functional outcomes at 3 months were assessed. Since 2023, patients have been treated according to a modified local standard operating procedure at our hospital, allowing for IVT despite DOAC pretreatment regardless of DOAC plasma levels or the use of reversal agents. Results: Of 1821 patients treated with acute recanalization procedures during the study period, N = 35 had received IVT with (18) or without (17) additional endovascular therapy. Among these patients with a wide age range (42–97 years) and DOAC plasma concentrations up to 369 ng/ml, only one developed symptomatic intracranial hemorrhage. A favorable outcome (modified Rankin scale score 0–2) after 3 months was observed in 57% (20) of the patients. Conclusion: IVT despite direct oral anticoagulation seems to be safe, even at advanced age and high DOAC plasma levels.

Der vorliegende Beitrag nimmt die Bedeutung der Berufsvererbung unter Lehramtsstudierenden in den Blick. Auf der Basis einer quantitativen Befragung von Studienanfänger:innen wird überprüft, ob sich Lehramtsstudierende, deren Eltern im Lehrer:innenberuf tätig sind bzw. tätig waren, im Hinblick auf ihre Studienwahlmotive sowie psychologischer Ressourcen von denen ohne solche Eltern unterscheiden. Die Ergebnisse der Studie verweisen darauf, dass sich die beiden untersuchten Studierendengruppen sowohl in Hinblick auf die Studienwahlmotive als auch die psychologischen Ressourcen unterscheiden. Entgegen der Forschungshypothese deuten die Ergebnisse aber auch darauf hin, dass idealistische Studienwahlmotive bei Studierenden mit Berufsvererbung höher ausgeprägt sind.

Tides significantly affect polar coastlines by modulating ice shelf melt and modifying shelf water properties through transport and mixing. However, the effect of tides on the marine carbonate chemistry in such regions, especially around Antarctica, remains largely unexplored. We address this topic with two case studies in a coastal polynya in the south-eastern Weddell Sea, neighbouring the Ekström Ice Shelf. The case studies were conducted in January 2015 (PS89) and January 2019 (PS117), capturing semi-diurnal oscillations in the water column. These are pronounced in both physical and biogeochemical variables for PS89. During rising tide, advection of sea ice meltwater from the north-east created a fresher, warmer, and more deeply mixed water column with lower dissolved inorganic carbon (DIC) and total alkalinity (TA) content. During ebbing tide, water from underneath the ice shelf decreased the polynya's temperature, increased the DIC and TA content, and created a more stratified water column. The variability during the PS117 case study was much smaller, as it had less sea ice meltwater input during rising tide and was better mixed with sub-ice shelf water. The contrasts in the variability between the two case studies could be wind and sea ice driven, and they underline the complexity and highly dynamic nature of the system. The variability in the polynya induced by the tides results in an air–sea CO2 flux that can range between a strong sink (−24 mmol m−2 d−1) and a small source (3 mmol m−2 d−1) on a semi-diurnal timescale. If the variability induced by tides is not taken into account, there is a potential risk of overestimating the polynya's CO2 uptake by 67 % or underestimating it by 73 %, compared to the average flux determined over several days. Depending on the timing of limited sampling, the polynya may appear to be a source or a sink of CO2. Given the disproportionate influence of polynyas on heat and carbon exchange in polar oceans, we recommend future studies around the Antarctic and Arctic coastlines to consider the timing of tidal currents in their sampling strategies and analyses. This will help constrain variability in oceanographic measurements and avoid potential biases in our understanding of these highly complex systems.

Despite a vast body of research on inclusive education, students' perspectives and experiences of inclusive secondary schools have garnered little attention. Yet their perspectives and experiences are central to the development of inclusive schools. To investigate this, we conducted seven group discussions with ninth-year students at German inclusive secondary schools, asking them what makes a school a place where all students can learn well. Using reflexive thematic analysis, we developed three themes (community, justice, and school as a place to live), three cross-thematic areas (limits, teachers, and belonging), and two overarching central discourses (othering and submission to a meritocratic, non-participative school logic). In light of our findings, we argue that inclusive secondary schools still face major challenges vis-a-vis the continuing non-inclusiveness of societies and that students' views can provide valuable insights into key success factors for inclusive secondary education. [ABSTRACT FROM AUTHOR]

Background: For patients experiencing ischemic stroke despite receiving therapy with direct oral anticoagulants (DOAC) and without endovascular treatment options, therapeutic prospects are currently dismal. Current guidelines recommend intravenous thrombolysis (IVT) only for patients who have received DOAC in very restricted settings, as an increased risk of bleeding is suspected. However, recent retrospective observational studies suggest that IVT is safe despite DOAC pretreatment. Objectives: To provide further evidence that IVT despite previous DOAC treatment is not associated with an increased risk of bleeding. Design: Observational retrospective study. Methods: Demographic, clinical, and radiological data of patients who received IVT (+/− endovascular thrombectomy) despite DOAC pretreatment between June 2021 and January 2024 were analyzed using descriptive statistics, including DOAC plasma concentration at admission. Secondary intracranial hemorrhages and functional outcomes at 3 months were assessed. Since 2023, patients have been treated according to a modified local standard operating procedure at our hospital, allowing for IVT despite DOAC pretreatment regardless of DOAC plasma levels or the use of reversal agents. Results: Of 1821 patients treated with acute recanalization procedures during the study period, N = 35 had received IVT with (18) or without (17) additional endovascular therapy. Among these patients with a wide age range (42–97 years) and DOAC plasma concentrations up to 369 ng/ml, only one developed symptomatic intracranial hemorrhage. A favorable outcome (modified Rankin scale score 0–2) after 3 months was observed in 57% (20) of the patients. Conclusion: IVT despite direct oral anticoagulation seems to be safe, even at advanced age and high DOAC plasma levels. Plain language summary: Bleeding problems after stroke treatment with clot-busting drugs, even when taking blood thinners After local treatment rules were changed to allow clot-busting treatment for stroke even if patients had recently used blood thinners, the number of patients receiving this treatment more than tripled. Despite not checking blood test results before treatment, serious brain bleeding was not common. The levels of blood thinners in the patients' blood did not affect the chances of having any kind of brain bleeding. This new information supports the growing evidence that clot-busting treatment may be safe for patients taking novel blood thinners. [ABSTRACT FROM AUTHOR]

The unsymmetrical diborane(4) derivative [(d(CH2P(iPr)2)abB)–Bpin] (1) proved to be a versatile PBP boryl pincer ligand precursor for Co(I) (2a, 4a), Rh(I) (2–3b) and Ir(I/III) (2–3c, 5–6c) complexes, in particular of the types [(d(CH2P(iPr)2)abB)M(PMe3)2] (2a–c) and [(d(CH2P(iPr)2)abB)M–PMe3] (2b–c). Whilst similar complexes have been obtained before, for the first time, the coordination chemistry of a homologous series of PBP pincer complexes, in particular the interconversion of the five- and four-coordinate complexes 2a–c/3a–c, was studied in detail. For Co, instead of the mono phosphine complex 2a, the dinitrogen complex [(d(CH2P(iPr)2)abB)Co(N2)(PMe3)] (4a) is formed spontaneously upon PMe3 abstraction from 2a in the presence of N2. All complexes were comprehensively characterised spectroscopically in solution via multinuclear (VT-)NMR spectroscopy and structurally in the solid state through single-crystal X-ray diffraction. The unique properties of the PBP ligand with respect to its coordination chemical properties are addressed.