University of the Philippines System

Homo luzonensis lived during the upper Pleistocene in the northern Philippines, east of the Wallace line. The few specimens attributed to this species show a mosaic of plesiomorphies for the genus Homo and apomorphies found in upper Pleistocene Homo species. Plesiomorphic traits could result from a close phylogenetic relationship with Australopithecus or Homo habilis/rudolfensis or from insular evolution favouring reversals, possibly linked to a relationship with a more recent species like Homo erectus. We conducted a cladistic analysis based on dental and postcranial remains of adult H. luzonensis to test these hypotheses. The trees obtained indicate that both hypotheses are supported by different anatomical elements. The trees suggesting H.luzonensis is close to H. erectus (as a sister-taxon or as a close relative of H. erectus) are supported by dental characters and feature high retention and consistency indices. Moreover, H. luzonensis likely had reduced body size and postural/locomotor modifications, similar to other insular mammals with medium-to-large-sized ancestors. The tropical forest environment of Luzon Island may have favoured the selection of these features. Based on these results and our current knowledge of insular evolution, we suggest that H. luzonensis likely evolved from an Asian H. erectus population in an insular context.

The Philippine Institute of Chemical Engineers (PIChE) held its 85th National Convention, themed “USWAG ChE! Strengthening the Profession through Collaborative and Holistic Engagement”, in Cebu City, Philippines, from September 11 to 14, 2024. This historic annual event was the most important gathering for the country's chemical engineering professionals. This book features a collection of papers on sustainability and innovations in chemical engineering.

Pure and silver-doped zinc oxide (ZnO) nanoparticles were synthesized via phyto-mediation using Stachytarpheta jamaicensis leaf extract to develop an eco-friendly method for synthesizing nanoparticles with enhanced properties. Zinc nitrate and silver nitrate were employed as precursors for ZnO and Ag-doped ZnO nanoparticles, respectively. The synthesized nanoparticles were characterized using Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM-EDS) to investigate their optical and morphological properties. Results revealed that the absorption peaks of the synthesized nanoparticles confirmed the formation of nanoparticles, with Ag doping causing a red shift in the absorption spectrum. SEM images indicated a spherical morphology, with slight agglomeration in the doped samples. Doping with silver enhanced the optical properties, which could have potential applications in catalysis, sensing, and biomedical fields. Furthermore, the nanoparticle extracts were subjected to antimicrobial test against two bacterial strains ( Escherichia coli and Staphylococcus aureus ) using a modified disk diffusion method and compared with the antibacterial effect with the standard antibacterial drug, Ampicillin. Ampicillin only showed antibacterial activity against S. aureus and had no antibacterial effect on E. Coli. Result of this study showed that the 5% and 10% Ag-doped ZnO NPs showed strong antibacterial activity against both gram-positive ( S. aureus ) and gram-negative ( E. coli ) bacterial strains.

Adsorbent beads composed of Chitosan (CS), MIL-101 (Fe), and Polyethyleneimine (PEI) were synthesized for Methyl Orange (MO) adsorption. Parametric studies testing the effects of pH and number of adsorption and desorption cycles on percent MO removal showed the beads’ good performance across a wide range of conditions. A percent MO removal of at least 93% was maintained from pH 2 to pH 9 with a maximum percent removal of 98.6% obtained at pH 3. In addition, the beads remained functional for at least 5 cycles of adsorption and desorption with a percent MO removal of 98% across the cycles. Kinetic modeling was performed and a pseudo-second order kinetic model with an R 2 of 0.981 was obtained implying chemisorption as the rate limiting step. Adsorption equilibrium data for MO were best fitted into the Sips isotherm model which suggests that adsorption occurs on a heterogeneous surface. From the Sips isotherm model, the maximum adsorption capacity was determined to be 1253.44 mg/g, highlighting the viability of CS – MIL-101 (Fe) – PEI beads as an adsorbent for wastewater treatment.

This investigation reports the successful synthesis and characterization of a co-crystal composed of paracetamol (PCM) and metal sulfates of zinc and iron using an adapted antisolvent addition technique which leveraged the antagonistic solvent affinities of PCM and the metal sulfates. Ethanol and water acted as solvents for PCM and the metal sulfates, respectively, while simultaneously serving as antisolvents for the other constituent. Scanning Electron Microscopy (SEM) micrographs revealed crystals exhibiting a rod-like structure and a surface covered by flakes, which are both characteristic features of PCM and zinc sulfate, suggesting the formation of a new crystalline phase. This is further supported by the distinct powder x-ray diffraction pattern for the co-crystal when compared with that of the individual constituents. Analysis of Fourier Transform Infrared (FTIR) spectra suggests that the interacting functional groups which formed a new hydrogen bond network are the amide N-H and the water in the aquo complex formed by the metals in aqueous solutions. The findings highlight the simplicity of the crystallization technique and provide insights into the structural and mechanistic aspects of organic-inorganic co-crystals. This study contributes to the advancement of co-crystal engineering and lays the groundwork for exploring the pharmaceutical and functional applications of PCM-metal sulfate co-crystals.

The environments of severe thunderstorms that produced hail were examined using 171 proximity soundings (2005-2024) archived in the 3rd Data Release of Project SWAP. These soundings were categorized based on their geographical occurrence into three hail-prone environments across Luzon, Philippines. For each case, key parameters describing instability, vertical wind shear, and moisture were calculated to assess the environmental conditions for hail production. The probability of hail occurrence, expressed as a function of WMAX (√2 × CAPE) and 0-6 km bulk shear (DLS), revealed patterns distinct from those reported in other regions. Hail events in Luzon were most likely under high CAPE conditions, where boundary-layer moisture was sufficient, mid- and low-level lapse rates were steep, and lifting condensation levels were high. Surprisingly, weak DLS was common across Luzon hail environments, diverging from existing severe weather climatologies, yet large DCAPE indicated environments conducive to damaging wind events. When DLS was replaced with the shear magnitude between the cloud base and equilibrium level, the probability of hail occurrence increased, better aligning with global severe weather climatologies. This finding is supported by hodograph analyses, which show largely unidirectional wind profiles: strong speed shear aloft but weak directional shear in the low-levels. Parameters such as WMAXSHEAR, WMAXSHEARLCL-EL, and BWDLCL-EL emerge as potential discriminators between non-severe and severe thunderstorms capable of producing hail, and as useful metrics for assessing convective storm severity in Luzon and possibly countrywide. Finally, two recurring severe setups conducive to hail were identified: (1) an easterly regime associated with trade winds, and (2) a westerly regime linked to the Asian summer monsoon.

Abstract. The existing methods for coconut mapping in the Philippines and globally are complex, necessitating the development of a simpler yet rapid and accurate classification technique. This study introduces the first spectral index for coconut mapping. Two Coconut Vegetation Indices were developed: one for dense Coconut Vegetation (CV) and another for sparse CV. CVIdense utilizes three Sentinel-2 bands in its equation (NIR1-SWIR1)/(SWIR1-SWIR2) to map coconut areas with densities >2.25 x10^6 sq.m. per 1km pixel. Meanwhile, CVIsparse incorporates four spectral bands in the equation (NIR1-Red)/(SWIR1-SWIR2) for areas with densities ≤ 2.25 x10^6 sq.m. per 1km pixel. The formulation of these indices is primarily based on previous studies involving band combinations and the analysis of spectral separability of the acquired coconut reflectance data. The extent of coconut vegetation was mapped using CVIdense with a minimum threshold of 1.094, while CVIsparse was applied using a threshold range of 0.4774 to 1.094. The Balanced Accuracy (BA) metric was used to assess the accuracy, accounting for the imbalanced reference data between coconut and non-coconut classes. CVIdense proved highly effective with User’s Accuracy (UA) of 80%, Producer’s Accuracy (PA) of 88.89%, and BA of 88.90%, surpassing CVIsparse, which had accuracies of 32.00% (UA), 53.33% (PA), and 74.10% (BA).

This chapter discusses the application of Applied Behavior Analysis (ABA) in teaching office skills to persons with intellectual disabilities (ID). Emphasis is placed on task analysis to break down complex office tasks into manageable steps, chaining to systematically connect these steps into functional sequences, and shaping to gradually build proficiency by reinforcing successive approximations. Reinforcement serves as a cornerstone strategy, motivating learners and strengthening desired behaviors. By applying these techniques, individuals with ID can acquire practical office competencies that enhance independence, employability, and workplace integration. The chapter underscores how structured, evidence-based instruction not only promotes skill mastery but also fosters confidence and meaningful participation in professional environments for persons with intellectual disabilities.

Background: Access to mental health services remains a critical public health issue, especially among young adults in urbanizing regions. Structural barriers and sociocultural stigma often hinder timely and appropriate mental health care. This study aimed to explore the barriers and facilitators that influence access to mental health services among young adults with mental health conditions. Methods: A qualitative descriptive design was employed. Sixty participants aged 18–32 years, diagnosed with depression, anxiety, or bipolar disorder, were purposively recruited. Data were collected via WhatsApp chat interviews and Google Forms between September and December 2024. Thematic analysis was used to identify emerging patterns in participants’ experiences. Results: Three major barriers to accessing mental health services were identified: stigma and social silence, limited availability of mental health professionals, and financial constraints. Conversely, three key facilitators emerged: supportive relationships, digital peer communities, and self-awareness. Participants highlighted the role of personal motivation and online networks in bridging formal care gaps, while systemic limitations remained prevalent in local service infrastructure. Findings reveal the dual nature of access to mental health services—where institutional barriers coexist with emerging forms of psychosocial resilience. Conclusion: Strengthening local mental health systems, improving service literacy, and expanding community-based and digital interventions are crucial steps to address mental health disparities among urban youth.