University of the Philippines Visayas

Abstract. Guimbuayan VB, Cordero CS, Alejandro GJD. 2025. Ethnobotanical survey of medicinal plants used by the Agta community in Gonzaga, Cagayan, Philippines. Biodiversitas 26: 6316-6334. Traditional knowledge of medicinal plants remains an integral part of primary healthcare systems in the Philippines, especially among indigenous communities. This study aimed to document the medicinal plant species used by the Agta indigenous peoples of Gonzaga, Cagayan, Philippines. From August 2024 to February 2025, 34 key informants were selected through purposive sampling and interviewed using a semi-structured questionnaire. Data were analyzed to determine the most culturally important species using Use Value (UV) and Informant Consensus Factor (ICF). Disease categories were classified in accordance with the World Health Organization International Classification of Diseases, 11th Revision (WHO-ICD 11). The Agta community reported 81 medicinal plant species, representing 74 genera and 37 families, with Poaceae being the most represented family (nine species). Leaves were the most commonly used plant part (41%), and decoction (43%) was the most frequent mode of preparation. Myristica sp. and Vitex arvensis were the most cited species, with UVs of 0.88 and 0.62, respectively. The highest ICF value (1.0) was recorded for disease category 5 (endocrine, nutritional, or metabolic diseases), followed by the Disease Categories 12 (Diseases of the Respiratory System) and 18 (Pregnancy, childbirth or the puerperium) and with ICF values of 0.76 and 0.71, respectively. This study provides the first documentation of the medicinal flora used by the Gonzaga Agta, offering a comprehensive inventory that underscores its dual significance for safeguarding cultural heritage and guiding future pharmacological research.

ABSTRACT Vibriosis, a bacterial disease, is considered a significant threat to the sustainability and economic viability of shrimp production. The present study evaluated the application of a predatory bacterium to control the population growth of pathogenic Vibrios in Pacific whiteleg shrimp (Penaeus vannamei). The predatory bacterium was identified as Bacteriovorax sp. OP175948.1 based on the 16S rRNA sequence. The Vibrio-inhibitory activity of Bacteriovorax sp. was evaluated using two independent trials with P. vannamei, exposed to two pathogenic Vibrios, including Vibrio parahaemolyticus and Vibrio harveyi. Each trial was conducted in five treatments, including a negative control, a positive control, and a treatment with Bacteriovorax sp. applied at 102, 104, and 106 plaque-forming units mL−1 (PFU mL−1). Results indicated that shrimp infected with V. parahaemolyticus and V. harveyi, and then treated with Bacteriovorax, showed a 6-fold increase in survival for V. parahaemolyticus and a 3-fold increase for V. harveyi, relative to the control. The shrimp treated with 104 to 106 Bacteriovorax sp. improved survival associated with a significant decline in Vibrio spp. counts in the shrimp tissues and rearing water. The Bacteriovorax sp. should be used as a practical strategy to prevent Vibrio-associated mortalities in P. vannamei aquaculture.

This study investigated the effectiveness of the flipped classroom as an academic support strategy in improving the Basic Calculus performance of Grade 11 STEM students at Himay-angan National High School. Employing a pre-experimental one-shot case study and descriptive survey design, the research compared third-quarter Basic Calculus grades from two cohorts: SY 2022–2023, which utilized traditional instruction, and SY 2023–2024, which implemented the flipped classroom approach. Students’ perceptions of and difficulties with the flipped classroom were also examined using validated questionnaires. Findings revealed that students exposed to the flipped classroom achieved higher academic performance, with a statistically significant difference in grades compared to those taught through traditional methods. Students’ perceptions of the flipped classroom were generally moderate to positive, indicating improved preparedness, engagement, self-paced learning, and collaborative opportunities. However, students also reported moderate difficulties, particularly in accessing online materials, managing time to watch instructional videos, and adapting to increased out-of-class workload. Despite these challenges, the overall results suggest that the flipped classroom effectively supports learning by promoting independent study, active classroom engagement, and constructivist learning processes. The study concludes that the flipped classroom is a viable and impactful academic support strategy for enhancing Basic Calculus learning outcomes among Senior High School STEM students and recommends its wider adoption with appropriate resources and instructional support.

ABSTRACT The high market value of certain essential oils (EOs), such as lemon essential oil (LEO), makes them particularly susceptible to adulteration. Such adulteration typically involves the intentional addition of low-value EOs. In this study, we mixed LEO and sweet orange essential oil (SOEO), lime essential oil (LiEO), and grapefruit essential oil (GEO) at varying concentrations. We then used Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR), and principal component regression (PCR), partial least squares regression (PLS), and artificial neural network (ANN) chemometrics to quantify adulteration in the samples. The ANN models produce the best accuracy, however it is computationally expensive and not practical. We further demonstrate that PLS using the 2000–1000 cm−1, ATR-FTIR spectral region produces good accuracy in predicting % v/v LEO, SOEO, LiEO, and GEO in the samples.