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Semi-confined supernova feedback in Hɪɪ region bubbles
No full textGalactic-scale simulations rely on subgrid models to provide prescriptions for the coupling between supernova (SN) feedback and the interstellar medium (ISM). Many of these models are computed in 1D to allow for an efficient way to account for the variability of properties of their local environment. However, small-scale simulations revealed that the release of energy from SNe within molecular clouds can be highly asymmetrical. This is largely due to the presence of pre-SN feedback, such as ionizing radiation, that are able to carve cavities and channels around the progenitors prior to their detonation. Being partially confined, the SN energy escapes into the outer ISM preferentially through these channels, departing from the spherically symmetric 1D descriptions. To understand by how much the feedback output could differ, we present a theoretical model for a semi-confined SN. The problem concerns a SN expanding into an evolved Hɪɪ region, bounded by a molecular cloud with pre-existing vents. With the aid of simple 3D hydrodynamical simulations, we show that this mode of energy release increases the local dynamical impact of the outflows, and extends the time-scales over which the SN is energetically coupled to the surrounding matter. We also show that the amount of small-scale solenoidal turbulence driven by semi-confined SNe may be amplified
Direct synthesis of polyesterether from ethylene glycol
No full textWe report here a method for making polyesterether from ethylene glycol. The reaction is catalyzed by a ruthenium complex and liberates H2 gas and H2O as byproducts. Mechanistic studies conducted through experiments and DFT computations suggest that the chain growth of the polymerization process involves both dehydrogenation and dehydration pathways stemming from a hemiacetal intermediate, leading to the formation of esters and ethers, respectively. Investigations into the polymerization of other diols have also been conducted, showing that diols with a lower number of carbons between the alcohol groups (propylene glycol, glycerol, and 1,3-propanediol) lead to the formation of polyesterether whereas α,ω-diols containing a higher number of carbons (1,6-hexanediol and 1,10-decanediol) lead to the formation of polyester
Progress in historical geography II:desperately seeking connections (again) – the mendacious, the micrological, and the mercurial
No full textHistorical geography’s core concern with connections between the past and present is currently expressed in an age marked by a desperate search for connections. The report considers how historical geography is linked to this scene through various ‘return of history’ ripostes and via the travails of what is described as its ‘pluriverse’. Three problematics are then identified: ‘the mendacious’ (about the truth of history); ‘the micrological’ (concern with biography and ‘small things’); and ‘the mercurial’ (regarding structural problems of violence and hope). Much for the subdiscipline now hinges on how the words freedom, truth, violence, and hope are treated
AT2021uey:a planetary microlensing event outside the galactic bulge
No full textWe report the analysis of a planetary microlensing event AT2021uey. The event was observed outside the Galactic bulge and alerted both space-(Gaia) and ground-based (ZTF and ASAS-SN) surveys. From the observed data, we find that the lens system is located at a distance of ∼1 kpc and comprises an M-dwarf host star of about half a solar mass, orbited by a Jupiter-like planet beyond the snowline. The source star could be a metal-poor giant located in the halo according to the spectral analyses and modelling. Hence, AT2021uey is a unique example of the binary-lens event outside the bulge that is offered by a disc-halo lens-source combination
International relations as a three dimensional space
No full textInternational Relations scholarship has traditionally represented the territory of a state as a contained claim to the flat surface of the Earth. Concerns for the workings of power across land are, for its part, so commonplace and taken for granted in the discipline that scholars writing thirty years ago, observed that land and its territoriality, referring to claims to its exclusive access and use, were remarkably little studied by students of the discipline. However, deepening environmental challenges like climate change and some of the activities and technologies aimed at supporting the shift away from fossil fuels, such as deep-sea mining in search of critical materials for the renewable energy transition, are constantly bringing the limitations of this conception of the state into view. Although several ways for moving out of this ‘container’ conception of the state have been put forward, this conception remains dominant. This dominance renders International Relations underprepared for meaningfully engaging with the off-land environmental risks that threaten to destabilize the political order that is the object of its study. Meaningful engagement can, however, be facilitated by putting traditional understandings of the territorial state in IR into productive dialogue with debates on volume unfolding in Political Geography. These debates have intensified largely in response to calls for scholars to complement their focus on the flatness of territory with increased and explicit attention to height and depth. International Relations, too, would benefit from more interdisciplinary engagement with these debates. This could be enabled through renewed attention to scale, materiality, and movement that does not adhere to the fixed, container logic of the territorial state. Studying IR in three dimensions might improve the awareness of IR scholars of the shifting material conditions for political organization and the likely consequences of these shifts on the institutional aspects of global order
Patterns of antibiotic resistance in urinary tract infections before and during the COVID-19 pandemic in Uganda and Tanzania
No full textBackground: Increased antimicrobial use during the COVID-19 pandemic has driven antimicrobial resistance (AMR) globally, particularly in resource-limited settings. This study assessed AMR patterns in urinary tract infections (UTIs) in Uganda and Tanzania before and during the pandemic. Methods: A cross-sectional study was conducted among UTI patients at healthcare facilities in Mbarara (Uganda) and Mwanza (Tanzania) between March 2019–September 2020 and January–December 2021. Mid-stream urine samples were collected and analysed following standard procedures. AMR patterns were compared across the two periods. Results: A total of 5563 patients were enrolled from Mwanza (55.0%, n = 3061) and Mbarara (45.0%, n = 2502). The overall prevalence of microbiologically confirmed UTIs in Mwanza was 32.5% (999/3060; 95% CI: 30.9%–34.3%), raised from 30.1% (655/2180; 95% CI: 28.1%–32.0%) before to 39.1% (344/880; 95% CI: 35.8%–42.4%) during the pandemic. Whereby, the overall prevalence of microbiologically confirmed UTIs in Mbarara was 24.8% (620/2502; 95% CI: 23.1%–26.5%), decreasing from 27.5% (502/1824; 95% CI: 25.5%–29.6%) before to 17.4% (118/678; 95% CI: 14.6%–20.5%) during the pandemic. The proportion of multidrug-resistant Gram-negative bacteria (MDR-GNB) rose significantly (74% versus 83.4%, P = 0.01) while MDR Gram-positive bacteria (MDR-GPB) increased slightly (55.5% versus 56.7%, P = 0.45) in Mwanza. Conversely, MDR-GPB increased substantially (31.4% versus 51.6%, P = 0.09) while MDR-GNB decreased (67.3% versus 61.9%, P = 0.22) in Mbarara. Conclusions: This study provides critical insights into AMR trends in UTI pathogens in Tanzania and Uganda, emphasizing the need for stringent antimicrobial stewardship, requiring ongoing surveillance and targeted interventions
Judiciary chiefs in hybrid regimes:Kenya
No full textThis article examines the critical role of judicial chiefs in hybrid regimes using Kenya as a case study. It highlights how judicial effectiveness arises from the complex dynamics of leadership, institutional independence, interdependence, and public support. Through an analysis of the tenures of Kenya’s first three Chief Justices post 2010—Mutunga, Maraga, and Koome—the study demonstrates that impactful judicial leadership transcends individual stature. Rather, it hinges on the judiciary’s ability to fulfill its judicial review mandate, protect institutional integrity, foster public trust, and collaborate with other government branches to fortify democracy. Each Chief Justice faced distinct challenges and adopted unique strategies to address them, highlighting the judiciary’s pivotal role in navigating political and constitutional pressures. The findings reveal that, in hybrid regimes, judicial efficacy depends on a judiciary’s capacity to uphold constitutional principles, assert its authority, and maintain independence amidst a volatile political environment. As Kenya’s judiciary continues to evolve, its leaders must focus on institutional cohesion, resource management, and public engagement to meet their democratic and constitutional responsibilities. This analysis reaffirms that in hybrid regimes, judicial resilience is essential for preventing authoritarian regression and advancing democratic constitutionalism