Journal of Hunan University Natural Sciences

Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and progressive pancreatic islet dysfunction. The mesenchymal stem cell (MSC)-derived secretome has been investigated as a potential cell-free therapeutic approach because of its reported paracrine, anti-inflammatory, and tissue-reparative effects. This study evaluated the effects of MSC-derived secretome administration on day-28 random blood glucose levels and pancreatic islet morphology in streptozotocin (STZ)-induced diabetic rats. Twenty-one male Sprague–Dawley rats were randomly assigned to three groups: negative control, diabetic control, and secretome-treated diabetic groups (n = 7 per group). The treated group received 0.5 mL of umbilical cord MSC-derived secretome intraperitoneally once weekly for three consecutive weeks, beginning on day 8 after STZ induction. Day-28 random blood glucose levels were analyzed using the Kruskal–Wallis test followed by Bonferroni-adjusted Mann–Whitney U tests. Pancreatic islet area was analyzed using one-way analysis of variance followed by Bonferroni-adjusted post hoc comparisons. Day-28 random blood glucose was lower in the secretome-treated diabetic group than in the diabetic control group (263.71 ± 122.29 vs. 423.00 ± 36.89 mg/dL; adjusted p = 0.0378). Pancreatic islet area differed among the three groups (p = 0.0043), with a significant difference between the negative control and diabetic control groups (p = 0.004). The difference between the diabetic control and secretome-treated diabetic groups was not statistically significant (p = 0.061). Qualitative examination of hematoxylin and eosin (H&E)-stained sections suggested better-preserved islet morphology in the treated group. These findings indicate lower day-28 random blood glucose following secretome treatment, while evidence for an improvement in pancreatic islet area remains inconclusive. The study does not establish β-cell regeneration.

Keywords: mesenchymal stem cell-derived secretome; streptozotocin-induced diabetes; random blood glucose; pancreatic islet morphology; Sprague–Dawley rats.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.12

Determining whether an arbitrary graph admits a graceful labeling remains an open problem in graph theory, as no general characterization of graceful graphs has been established. This study introduces the Upstairs graph, denoted by (Us_n), as a new graph structure based on a layered construction of grid graphs. Its graceful labeling properties are investigated through theoretical analysis and computational verification using a Python algorithm that checks the labeling conditions and generates visualizations of labeled graphs. The study provides a formal definition of the Upstairs graph and presents a general theorem stating that (Us_n) admits a graceful labeling for every integer (n\geq1). Illustrative cases demonstrate the labeling construction, while computational results are consistent with the theoretical results for the tested instances. Thus, the Upstairs graphs constitute a new family of grid-derived graphs with graceful labeling properties.

Keywords: graceful labeling; graph construction; graph labeling; grid graph; Python algorithm; Upstairs graph.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.11

This study examines consumers’ intentions to boycott brands associated with the Israel–Palestine conflict by extending the Theory of Planned Behavior (TPB) to include anticipated emotions, consumer animosity, perceived efficacy, and social media influence. Data were collected from 179 Indonesian consumers through a cross-sectional survey using five-point Likert-scale items and analyzed using partial least squares structural equation modeling (PLS-SEM). Negative anticipated emotions were the strongest predictor of boycott intention, suggesting that anticipated guilt, regret, and moral discomfort about not participating are associated with a greater intention to boycott. Consumer animosity, however, was not significantly associated with boycott intention. The model explained 78.5% of the variance in boycott intention. These findings highlight the relevance of anticipated emotions and perceived efficacy to the study of consumer boycott intentions in geopolitical contexts. They may also help organizations understand consumer responses to socially sensitive issues.

Keywords: consumer boycott intention; Theory of Planned Behavior; consumer animosity; perceived efficacy; social media influence; anticipated emotions; Indonesia.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.10

Landslides on steep slopes composed of tropical volcanic soils constitute a major geotechnical hazard because intensive weathering and variations in water content can substantially affect soil shear strength and slope stability. This study evaluated the effectiveness of moisture-controlled compaction in improving the stability of a steep roadside slope in Aek Godang Arbaan Village, Onanganjang District, Humbang Hasundutan Regency, North Sumatra, Indonesia. The engineering properties of the soil were determined through laboratory Proctor compaction and direct shear tests to obtain the optimum moisture content (OMC), maximum dry density, cohesion, and internal friction angle. Slope stability was assessed using the Fellenius and Bishop limit equilibrium methods and a three-dimensional finite element model developed in PLAXIS 3D using the φ–c reduction approach. Three moisture conditions were considered: 14.70% on the dry side of the OMC, an OMC of 19.25%, and 23.80% on the wet side. The Proctor test yielded an OMC of 19.25% and a maximum dry density of 1.614 g/cm³. At the OMC, the factors of safety calculated using the Fellenius, Bishop, and PLAXIS 3D methods were 1.51, 1.66, and 1.997, respectively. The Bishop method produced a slightly higher factor of safety under the dry-side condition of 14.70% (1.69) than at the OMC (1.66), whereas the Fellenius and PLAXIS 3D analyses exhibited different trends. Nevertheless, when maximum dry density and the combined results of the three stability analyses were considered, the OMC of 19.25% was identified as the most favourable overall compaction condition. PLAXIS 3D provided additional insight into the stress distribution, deformation pattern, and progressive failure mechanism that could not be represented by the limit equilibrium methods. The large deformation values generated during the φ–c reduction analysis indicate numerical progression towards failure and should not be interpreted as predicted service-condition displacements. These findings demonstrate that controlling the water content during compaction at or near the OMC can enhance the stability of steep tropical volcanic soil slopes and provide a practical basis for slope stabilisation and landslide-risk mitigation.

Keywords: moisture-controlled compaction; slope stability; tropical volcanic soil; limit equilibrium method; finite element analysis.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.9

Climate change increasingly threatens farmers’ livelihoods and heightens the vulnerability of smallholder farming communities in flood-prone areas. Integrated agricultural and livelihood strategies are therefore needed to strengthen resilience and ensure long-term environmental and socioeconomic sustainability. This study aimed to develop and validate the Sustainable Livelihood Model for Flood Resilience Strategies (SLIMFRESS) for smallholder rice farmers in South Sumatra Province, Indonesia. An explanatory sequential mixed-methods design was employed, in which quantitative data were analysed first and subsequently complemented by qualitative evidence obtained from relevant stakeholders. A system dynamics model was developed using STELLA Architect 9 through causal-loop diagrams, stock-and-flow diagrams, and model validation procedures. Thematic analysis of stakeholder perspectives was conducted alongside the system dynamics modelling process to interpret the quantitative findings and refine the structure of the model. The resulting SLIMFRESS model integrates farmers’ sustainable livelihood assets with sustainable livelihood strategies to assess interventions aimed at reducing the economic and environmental risks associated with flooding in rice-farming areas. The simulation results indicate that livelihood resilience does not develop immediately but emerges gradually through sustained support, continuous knowledge development, and effective institutional collaboration. The model also highlights the importance of coordinated interventions addressing environmental conservation, household financial security, and market participation. Accordingly, policy measures should prioritise community-based conservation initiatives, financial mechanisms providing income support and agricultural insurance during flood events, and improved market access for products developed by smallholder enterprises. SLIMFRESS provides an integrated decision-support framework for designing and evaluating long-term flood-resilience strategies for smallholder rice-farming communities.

Keywords: sustainable livelihoods; flood resilience; system dynamics modelling; smallholder rice farmers; climate change adaptation.

DOI https://doi.org/10.55463/issn.1674-2974.53.8.8