Judul: Model Penduga Volume Pohon Mahoni Daun Besar (Swietenia macrophylla, King) di Hutan Rakyat Kecamatan Klirong Kabupaten Kebumen
Abstrak: Mahoni merupakan jenis pohon yang paling banyak ditanam masyarakat di Kecamatan Klirong Kabupaten Kebumen. Namun sampai saat ini belum ada alat penduga volume pohon mahoni yang dapat digunakan oleh petani untuk menduga volume pohon dan tegakan mahoni untuk mendukung proses penjualan kayu. Penelitian ini bertujuan untuk menyusun model volume pohon mahoni dan membandingkan ketelitiannya dengan pendugaan volume menggunakan angka bentuk pohon. Penelitian ini menggunakan 120 pohon untuk pembuatan model dan untuk validasi menggunakan 30 pohon contoh lainnya yang dipilih secara purpossive di lokasi penelitian. Model penduga volume disusun dalam 9 bentuk persamaan regresi dengan diameter dan/atau tinggi sebagai peubah bebas. Hasil penelitian menunjukkan bahwa model terbaik adalah V9 dengan persamaan V = 0.00012 D1.89675 H0.66353 (R2adj = 0.9688, s = 0.0329 m3). Namun untuk kepraktisan di lapangan dapat digunakan V7 dengan persamaan V = 0.00043 D2.03317(R2adj = 0.9525, s = 0.0399 m3). Pendugaan volume dengan angka bentuk absolut (0.46) lebih teliti dibanding pendugaan volume dengan angka bentuk buatan (0.69).
Keyword: hutan rakyat, angka bentuk, model volume

Judul: Model Penduga Volume Pohon Mahoni Daun Besar (Swietenia macrophylla, King) di Hutan Pendidikan Gunung Walat, Sukabumi, Jawa Barat
Abstrak: Tree volume is one of the important data to determine the potential of wood in Gunung Walat Educational Forest. This research aims to obtain estimator model for the commercial volumes of the big leaf mahogany (Swietenia macrophylla King), either volume estimator model for the commercial unbranched tree or volume estimator model for the commercial branched tree. The largest correlation coefficient value between the breast height diameter and tree volume was in the commercial unbranched tree category, that was 0.981. The conditions of big leaf mahogany trees caused many differences of derived volume estimator models. From the results of the validation test, it obtained two volume estimator models with the same good level of reliability, those were V = 0.00010992D2.319 to estimate stem volume in the commercial unbranched of big leaf mahogany tree and V = 0.00015792 D2.314 to estimate the total volume in the branched commercial of large leaf mahogany tree. Both volume estimator models can be used to estimate the volume of big leaf mahogany trees in Gunung Walat Educational Forest.
Keyword: Bogor Agricultural University (IPB), volume estimation models, big leaf mahogany

Judul: Durability of Specific Immunoglobulin (Ig) Y Againts Influenza and Covid-19 in Sunscreen
Abstrak: The benefit of specific immunoglobulin Y (Ig Y) as an active ingredient in personal care products such as sunscreen has not been properly studied. Our study aims to evaluate the reliability of specific IgY against influenza and the COVID-19 virus in a sample sunscreen product. Specific IgY influenza and COVID-19 viruses were inserted in the sample sunscreen at two concentrations of 0.1% and 0.25%. Three treatments were observed: control (C) sunscreen without IgY, treatment 1 (T1) sunscreen with 0.1% IgY, and treatment 2 (T2) sunscreen with 0.25% IgY. Organoleptic observations were carried out to monitor changes in aroma, color, and texture, and sunscreen sampling was done every week for 6 weeks. The durability of IgY was evaluated using an enzyme-linked immunosorbent assay (ELISA) and a neutralization assay. Organoleptic observation from weeks 1 to 6 showed consistency in its aroma, color, and texture. Enzyme-linked immunosorbent assay and neutralization assay (NA) results of the T1 and T2 groups showed negative results except for sample T1 at week 5, which showed a positive result in the Influenza A ELISA. Based on the results, it seems that IgY concentrations of 0.1% or 0.25% were not optimal. However, this negative result might be due to low concentration of the IgY and the presence of beeswax, which inhibits IgY and causes it to dissolve in distilled water, thus preventing it from being detected in the assay.
Keyword: Immunoglobulin Y, Sunscreen, Influenza, COVID-19, Biological Activity