Advancing Open Science

Delayed density dependence is a significant process in insect population dynamics; nonetheless, its identification and resulting dynamical implications remain subjects of substantial contention. Motivated by this controversy, we investigate a two-generation discrete-time model of the form where . This model integrates both instantaneous and one-generation-lagged density dependence via a weighted amalgamation of successive population densities. Based on general assumptions regarding the diminishing recruitment function f, we delineate the local asymptotic stability of the positive equilibrium and demonstrate that the ratio ${\displaystyle \frac{a}{b}}$, which quantifies the relative influence of direct versus delayed density dependence, plays a crucial role in determining stability and its structure. The stability region is maximized when $a=3b$; if $a<3b$, stability may be compromised by a Neimark–Sacker bifurcation, whereas for $a>3b$, it may be compromised through a period-doubling bifurcation. We also investigate strong local asymptotic stability and identify additional parameter regimes satisfying this criterion after the first expansion. Separately, we establish global asymptotic stability under explicit sufficient conditions by constructing enveloping maps. As prototypes, we consider Ricker- and logistic-type models. We implement the overarching theory, derive explicit invariant regions, establish bifurcation criteria, and obtain global stability results. The examination underscores that the balance between direct and delayed density dependence can significantly alter the qualitative behavior of insect populations.

In this study, comparative experiments on picosecond laser drilling were conducted in three different environments: air, water-based, and underwater. By varying the laser power (11–15 W), the effects of different water-assisted methods on hole diameter, taper, sidewall morphology, and oxidation degree were analyzed, and the laser drilling mechanisms operating under these conditions were revealed. The experimental results showed that both water-based and underwater assistance significantly improved laser drilling quality. In the underwater environment, the water thickness was greater than in the water-based case. Laser energy attenuation became more pronounced when the beam reached the bottom of the hole, further reducing the material removal rate. This resulted in a smaller exit diameter than under the water-based conditions and thus a larger taper. However, since the workpiece was fully submerged throughout the process, almost no molten material was observed at the entrance. The roughness at the entrance and middle of the hole was lower than in the water-based environment. Nevertheless, the water layer in the underwater environment isolated the workpiece from air, enabling drilling under near oxygen-free conditions. The oxygen content of the sidewalls was significantly reduced compared to the air environment.

Whether advances in global weather forecasting translate into local forecast skill requires regional verification. Using observations at 117 stations in Inner Mongolia during the June–August 2026 flood season, we compared three publicly distributed forecast fields at 6–84 h lead times: the Integrated Forecasting System control forecast (IFS-Control), the Artificial Intelligence Forecasting System (AIFS), and WeatherNext 2’s 64-member ensemble mean (WN2). Because WN2 is an ensemble mean and the others are single deterministic forecasts, this compares operational products, not the underlying models. Verification of 2 m temperature and precipitation used Murphy error decomposition and block-bootstrap sensitivity tests. Temperature mean absolute error was approximately 15.7% lower for AIFS and 13.1% lower for WN2 than for IFS-Control, mainly through smaller correlation-error terms, though IFS-Control had the smallest systematic bias. Both AI products outperformed IFS-Control for 6 h moderate rain (≥4 mm). IFS-Control robustly outperformed AIFS for 6 h heavy rain (≥13 mm), but its advantage over WN2 did not survive the stricter multiple-comparison correction. Both AI products under-forecast heavy-rain frequency and extremes; a limited member experiment suggests ensemble averaging may contribute, though not separably from model differences. Findings apply only to the product versions, region, and season evaluated.

In this study, we investigated the effects of donor cell on the efficiency of producing cloned Ỉ pigs, an endangered Vietnamese breed. Cloned Ỉ pig embryos were generated using somatic cell nuclear transfer technology (SCNT). The results demonstrated that pregnancy, farrowing, and piglet production rates of Ỉ pig fibroblasts (ID:6004) at the 5th and 6th passages were significantly higher compared with those observed at the 4th and 7th passages. Under the conditions of this study, no significant effect of donor cell sex or cell lines on the efficiency of cloned Ỉ pig embryo transfer was observed. The pregnancy, farrowing, and piglet production rates did not differ significantly between donor cell groups of male and female origin (p > 0.05). Similarly, no significant differences were observed in pregnancy rates, farrowing outcomes, or one-week survival of live cloned piglets among the three donor cell lines (IDs: 6004, 9154, and 9157) (p > 0.05). These findings contribute to improving the efficiency of the somatic cell nuclear transfer (SCNT) technique in efforts to conserve the critically endangered Vietnamese Ỉ pig.

Commercial nonionic sucrose ester surfactants (SEs) contain varying ratios of monoesters and polyesters. In our previous study, we found that when the mono-to-polyester (MP) ratio is close to 1, SE dispersions can form hydrogels at very low surfactant and electrolyte concentrations. In the current study, we systematically investigate how the MP ratio and particle size affect the salt-induced gelation process. We reveal that SE dispersions form hydrogels only within a certain MP range. At low MP ratios (<0.4), micrometer-sized particles form and sediment, preventing gel formation, whereas at high MP ratios (≳3), particle concentration decreases, confining gelation to a very narrow electrolyte region. Sonication significantly reduces particle size across all dispersions, expanding the gelation domain down to MP ≈ 0.3. The critical salt concentration required for hydrogel formation exhibits a maximum as a function of MP ratio at MP ≈ 0.43, which is explained with the highest measured zeta potential for these particles. The obtained results support the hypothesis that increasing the monoester content enhances surface mobility, suppresses hydroxide ion adsorption, and reduces particle charge, thereby lowering the threshold electrolyte concentration. Finally, particle size reduction enhances overall gel strength and lowers the minimum surfactant concentration required for gelation. These findings enable the rational design of simple, biodegradable hydrogels with tunable properties for future applications in food, pharmaceutical, and cosmetic formulations.

Student support in open and distance e-learning (ODeL) higher education remains unevenly governed, particularly for historically disadvantaged, low-income, rural, and disabled students. This systematic review compares how governance structures shape equitable student support in the United States and South Africa, two systems marked by histories of racial segregation and apartheid and by persistent racial, socioeconomic, technological, and disability-related inequalities. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the review searched five databases and relevant policy repositories, screening 773 records and appraising 123 full-text reports. Twenty-one sources met the inclusion criteria, comprising 13 empirical studies and eight governance and policy documents published mainly between 2013 and 2025. Because the corpus was deliberately bounded to governance evidence from two national systems, the review is a focused comparative synthesis rather than an exhaustive account of distance education provision in either country. A thematic synthesis examined legislation, funding, disability provisions, quality assurance, and institutional accountability. Findings show that both countries articulate strong equity commitments but experience persistent implementation, monitoring, and accountability gaps, with the digital divide undermining support for rural and low-income learners. Contextual differences in funding models and regulatory design generate transferable lessons. The review proposes an equity-oriented governance framework that links foundational equity values, four governance pillars, and continuous monitoring to strengthen inclusive, accountable, and sustainable student support.

Background/Objectives: Undernutrition remains an important contributor to morbidity and mortality among children under five years of age, particularly in rural and low-resource settings. This study determined the proportion of children with documented readmission for undernutrition and identified associated factors at Bela-Bela District Hospital, Limpopo Province, South Africa. Methods: A retrospective analytical hospital record review covering January 2018 to December 2025 was conducted. Of 538 medical records identified, 94 were excluded, 444 remained eligible, and 222 were selected through systematic random sampling. Clinical, caregiver/household conditions, healthcare-related and post-discharge data were extracted. The primary outcome was documented readmission for undernutrition at Bela-Bela District Hospital following discharge. Multivariable logistic regression was used to identify independently associated factors. Results: Of 222 children, 54 (24.3%) had documented readmission. Previous admission for undernutrition was strongly associated with documented readmission (AOR = 4.12; 95% CI: 2.00–8.50; p < 0.001). Lack of documented caregiver nutrition education (AOR = 3.10; 95% CI: 1.40–6.90; p = 0.005), absence of a documented follow-up date (AOR = 2.20; 95% CI: 1.05–4.60; p = 0.036), and failure to attend follow-up according to schedule (AOR = 1.95; 95% CI: 1.05–3.60; p = 0.030) were also associated with documented readmission. Conclusions: Documented readmission was associated with previous admission for undernutrition and gaps in documented post-discharge care. These findings highlight the importance of strengthening post-discharge planning, documentation of caregiver nutrition education, documentation of follow-up appointments, and continuity of nutritional support.

Nature reserves serve as core areas for maintaining ecological functions in karst regions, and their conservation efficacy and surrounding influence are crucial to ecological security. However, knowledge gaps remain regarding spillover effects, driving mechanisms, and key areas around nature reserves across landform types in the Southern China Karst. This study examines conservation effectiveness, spillover effects in surrounding buffer zones (5–10 km), and driving mechanisms across NRs of different landform types. Results show that ecosystem services decline along the gradient of “nature reserves–5 km buffer zone–10 km buffer zone”. The 5 km buffer shows stronger potential spillover patterns than the 10 km zone, particularly for carbon storage and soil conservation. The karst fault basin exhibits higher protection efficiency in the 5 km buffer zone than within nature reserves, indicating ecological feedback. Environmental variables are direct positive drivers of integrated ecosystem services; vegetation variables exert the strongest positive mediating effect via environmental variables; degradation variables show region-dependent mediating effects; and the negative direct effect of human-activity variables weakens with distance, alongside positive mediating effects. This study fills knowledge gaps concerning the spatial differentiation of conservation effectiveness and ecological key areas, offering support for ecological protection and restoration.