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Microfluidic Engineering of Chitosan‐Coated Nanoemulsions for Controlled Release and Stability in Space Pharmaceutics
Get PDFLong-duration exploration missions demand liquid medications that remain safe and effective without frequent resupply. We report a microfluidic-assisted spontaneous emulsification strategy to produce an injectable, melatonin-loaded oil-in-water nanoemulsion (MNE) and a chitosan-coated variant (CCMN) engineered for space use. Medium-chain triglyceride oil with an optimized Tween 80/Span 80 blend (hydrophilic-lipophilic balance, HLB = 11) and glycerol as co-surfactant yielded self-emulsifying regions at low surfactant load, while in-line chitosan coating of the droplets tuned interfacial mechanics. Formulations were screened by pseudo-ternary phase diagrams and thermodynamic stress tests, characterized by dynamic Light Scattering (DLS), zeta potential, viscosity, pH and imaged by cryogenic transmission electron microscopy. The 0.25% chitosan coating produced small, narrowly distributed droplets (152 nm; polydispersity (PDI) = 0.16) with moderated surface charge and injection-compatible viscosity, while uncoated controls were 172 nm. Under accelerated thermal stress (40°C–45°C; 28 d) CCMN limited size growth relative to uncoated nanoemulsions, and on a random positioning machine (0 g gravity-vector-average; 28 d) CCMN maintained size and polydispersity with no measurable coalescence; uncoated systems showed non-destructive fluctuations. In vitro drug release followed the Weibull model for both formulations. CCMN showed sustained profile (∼65% at 12 h) relative to faster release from MNE (∼83% at 12 h)
Early Pleistocene ecosystem turnover in South Siberia linked to abrupt regional cooling
Get PDFEarth system feedbacks can amplify greenhouse gas forcing but are difficult to quantify, particularly on land where long palaeoclimate records are scarce. Here we reconstructed warm-season temperatures and vegetation at Lake Baikal, Russia, over the past 8.6 million years. We document gradual late Neogene cooling that was punctuated by an abrupt transition approximately 2.7 million years ago to severe cold temperatures during glacial periods. Forests were replaced by open steppe–tundra ecosystems and permafrost probably extended into South Siberia during these Early Pleistocene cold intervals. Compiled palaeobotanical data suggest this ecosystem turnover occurred throughout the Arctic and subarctic, although the timescale of these changes is less understood. Reconstructed Early Pleistocene glacial temperatures and vegetation resemble Late Pleistocene glacial periods at Lake Baikal, despite much warmer mean global temperatures in the Early Pleistocene. These geologic observations support the view that regional climate can respond nonlinearly to global forcing. We hypothesize that both vegetation albedo and permafrost carbon storage may have played a key role in amplifying glacial–interglacial climate cycles through the last 2.7 million years alongside ocean and ice sheet feedbacks
Gender as an issue of curricular (in)justice: A review of national early childhood education curriculum documents in England from 1996-2021
Get PDFIn England, gender is currently a controversial issue, with debates in social and political spheres increasingly impacting educational policy. Simultaneously, scholarship on gender in Early Childhood Education (ECE) advocates more gender-sensitive pedagogies to disrupt restrictive and essentialised views. We use Connell's principles of curricular justice to analyse gender's position in England's birth-to-five policies. Taking as the lynchpin of our analysis Connell's third principle, the historical production of equality, we trace gender's representation in fourteen birth-to-five statutory and non-statutory curriculum documents from 1996-2021, identifying the extent to which these curricula support practitioners to teach in just and equitable ways. A picture of curricular injustice becomes evident. Our review highlights how changes in the broader political system result in three shifts in gender's curricular positioning (defined as gender foundations; gender awareness; gender decline) that ultimately fail the needs of the least advantaged and inhibit children's preparation for democratic participation in society. The ideological (re)production of gender (in)justice in the curricula occurs, firstly, through limited references to gender, fluctuations in gender's use over time, and gender's siloing in non-statutory statements. Secondly, conceptual confusion, the use of binary constructs, and a reliance on both legal non-discrimination and an equal opportunity framing, restrict gender justice. This review exposes the ways in which the reproduction of social power in the ECE curriculum reinforces gender inequalities, thus raising questions about the curriculum's suitability for supporting socially just, gender-sensitive pedagogy in ECE. We conclude that now is the time for a renewal of curricular justice
Strategic profiles and tactical shifts: Rethinking China’s digital diplomacy
Get PDFThis article revisits assumptions about China's "Wolf Warrior" diplomacy by analysing patterns in official digital communication. Drawing on a manually coded sample of 3,846 tweets from verified Chinese diplomatic accounts (2017-2022), we identify five recurring communication profiles-Informer, Promoter, Complex Challenger, Taiwan Challenger, and Provoker-that reflect consistent combinations of tone, function, topic, and geographic focus. Using cluster analysis and weighted scoring, we track how these profiles feature across time and diplomatic context. Rather than showing a wholesale turn toward confrontational rhetoric, the data reveals a stable messaging repertoire where more assertive profiles appear selectively and temporarily. A case study of the COVID-19 pandemic further illustrates how diplomats intensified certain styles during periods of reputational pressure while maintaining continuity in broader messaging. The study offers a structured framework for understanding how state actors organise digital communication through patterned variation, challenging simplified narratives of an aggressive diplomatic turn
Hydrodynamic performance analysis of marine propellers with avian-inspired bionic blade sections: a numerical study
Get PDFThe hydrodynamic performance of a propeller directly influences ship operational expenses, whereas cavitation adversely affects the operational performance of marine propellers, manifesting as diminished efficiency, accelerated material degradation, and acoustic emissions. Enhancing hydrodynamic performance and suppressing cavitation on blades remains a significant challenge in contemporary propeller design. This study modified the thickness distribution of blade sections on a MAU 5–80 propeller through a bionic design with different avian-wing geometries, and three marine propellers with novel bionic blade sections were established. Based on the SST k-ω turbulence model and Schnerr-Sauer cavitation model, the open-water characteristics and cavitation performance were analyzed numerically. Under open water conditions, compared to the prototype propeller, accipiter nisus and merganser wing-inspired propellers produce greater thrust, and the owl wing-inspired propeller simultaneously improves both thrust and efficiency across different advance speeds, achieving efficiency increments of 1.19% and 1.22% at J=0.2 and 0.9, respectively. Under cavitation conditions, the owl wing-inspired propeller increases the cavitation area, whereas the accipiter nisus and merganser wing-inspired propellers decrease the cavitation area by 17.2% and 14.21%, respectively, at J=0.6. The results demonstrate that avian-wing geometries with low-drag performance can improve the propeller open-water characteristics but may increase the cavitation risk
Military Labor Systems, Domestic Politics, and the Battlefield
Get PDFResearch has demonstrated that decisions around military conflict can significantly impact governments’ political survival. One important strand of the extant literature has focused on the impact of military labor systems, with most academic studies distinguishing between two types of systems: conscription, in which citizens are compelled to serve; and market-based enlistment according to which citizens self-select into military service. In this article, we argue that this conceptualization of military labor systems misses substantial theoretical and empirical variation in recruitment of military personnel over time and across cases. We make two contributions. First, we introduce new data that allow us to capture an important and common additional category of military labor acquisition—selective conscription. Second, we use these new data to empirically demonstrate that selective systems afford governments significant opportunities to manipulate how the costs of military conflict are distributed across the population. Specifically, we provide empirical evidence showing that countries with selective conscription are more willing to tolerate battlefield casualties
Gender differences in household education expenditure in Malaysia
Get PDFPurposeThe objective of this study is to examine gender differences in the allocation of household expenditure on education in Malaysia.Design/methodology/approachThis study examines the determinants of expenditure on education using a double hurdle model, where the decision to incur education expenditure is modelled first and followed by the decision on how much to spend on education.FindingsThe results show evidence of significant gender differences in the allocation of expenditure on education. For young children (4–12 years) and adult (18–23 years), this bias tends to favour females, while for secondary-aged children, the bias is pro-male.Practical implicationsThese findings may reflect a cultural shift in attitudes towards female education, although the effects are likely to be compounded by a lower completion rate of boys in upper secondary education, a growing concern that cannot be ignored by the government, policymakers or households.Originality/valueThis study utilises the Malaysia Household Expenditure Survey (HES) 2022 dataset to make two important contributions. First, conditional on enrolment, it investigates the extent to which there are gender differences at the household level in the allocation of expenditure at every level of education. Second, it examines the model by region and includes intergenerational effects in examining its indirect effects on the gender gap
Temporal Trends in Medical and Surgical Management of Ulcerative Colitis in England: 2003–2020
Get PDFBackgroundThe medical management of ulcerative colitis (UC) is evolving. However, colectomy may be required in severe or refractory cases.AimTo provide contemporary evidence on medication usage and surgery for UC.MethodsAn incident cohort of patients newly diagnosed with UC from 2003 to 2020 was identified using computerised health records. The cumulative incidence of colectomy and medication use was calculated using Kaplan–Meier methods and compared across 3 time periods. We calculated 90-day post-operative mortality using life tables. Cox regression was used to model the risks of surgery and mortality, adjusting for confounders.Results39,198 subjects had an incident diagnosis of UC. 5-year cumulative incidence of elective colectomy reduced from 2.60% to 1.30%, and emergency colectomy from 3.27% to 2.27% from 2003–2007 to 2015–2020. For elective surgery, adjusted hazard ratio (aHR) 0.44 and for emergency surgery, aHR 0.58 when 2015–2020 was compared to 2003–2007. Colectomy was less likely in women (elective aHR 0.74, emergency aHR 0.71) and emergency colectomy was less likely in those aged 40–59, aHR 0.86 than in those aged 18–39. Ninety-day mortality for elective and emergency surgery was 1.58% and 4.21%, respectively. Use of advanced therapies increased from 2% to 16% at 5 years from diagnosis when comparing 2003–2007 and 2015–2020.ConclusionColectomy in the five years following diagnosis has declined, coinciding with an increased use of advanced therapies. Overall post-operative mortality is low. While the indication for colectomy may influence the risk of adverse outcomes, aggregate data provide a reassuring picture of current practice
Unified Neural Network-Based Shape Sensing for Continuum Robots Using Fiber Bragg Gratings
No full textContinuum robots require precise shape sensing for reliable operation in constrained industrial and medical environments. We present a unified neural network that improves fiber Bragg grating shape sensing across two distinct continuum robots (a 165mm fully actuated robot and a 1.5m hybrid robot in a mock aero-engine) and multiple fiber configurations. Using camera-tracked ground truth, a single per-fiber model corrects distal positions from raw fiber Bragg grating estimates, implicitly compensating for twist and placement errors. On the 165mm robot we achieve 0.95mm root-mean-square error (0.57% length); on the 1.5m robot we achieve 2.02mm (0.13%) in 2-D and 1.78mm (0.11%) in 3-D, while reducing worst-case errors by up to an order of magnitude versus baselines. The model runs at >100 Hz and enables real-time, camera-free operation
Vulnerability Across Borders: Au Nord d’Albany and Absence of Wings
No full textThis article addresses vulnerability in the Americas via a comparison of a Québécois film, Au nord d’Albany (North of Albany; dir. Farley 2022) and an Anglo-Canadian collection of poetry, Arleen Paré’s Absence of Wings (2023). The constituent nation-states represented in these texts have specific relationships to each other and to continental assertions of power; moreover, power and vulnerability within these nation-states—not simply across them—vary significantly. Both the film and the collection revolve around the figure of a Black daughter to a single, white mother who attempts to mitigate elements of vulnerability for their daughter’s sake. Whereas Au nord d’Albany’s contrast between Canada and the United States both reinforces and troubles stereotypical distinctions between these nation-states, Absence of Wings focuses primarily on the racist failings of the Canadian state, while also invoking the United States and Brazil. Borders constitute obvious sites of adjacency, but the nature of this “up againstness” is not the same at every border, or for every border crosser, as uneven relations of hospitality and hostility attest. To different degrees, Au nord d’Albany and Absence of Wings demonstrate that the Canadian nation-state, despite its long-established rhetoric and policies of multiculturalism, presents little difference from other countries of the Americas in the precarity that structures life unevenly
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