Judul: Akurasi Pendugaan Biomassa Pohon Pinus Berdasarkan Konversi Volume Pohon di Hutan Pendidikan Gunung Walat
Abstrak: Metode alternatif untuk pendugaan biomassa pohon konversi volume pohon menjadi biomassa dengan menggunakan koreksi volume silinder, kepadatan kayu, dan Faktor Ekspansi Biomassa (BEF). Metode ini umumnya digunakan ketika model biomassa alometrik yang sesuai tidak tersedia. Penelitian ini bertujuan untuk mengetahui faktor bentuk, kerapatan kayu, dan BEF pohon pinus serta menganalisis keakuratannya dalam pendugaan biomassa pohon pinus dengan menggunakan konversi volume pohon. Penelitian ini menggunakan pengambilan sampel destruktif 11 sampel pohon pinus di kawasan rehabilitasi di Hutan Pendidikan Gunung Walat (HPGW). Pohon contoh dianalisis untuk menentukan volume batang, faktor bentuk, kerapatan kayu, dan total biomassa pohon. Untuk setiap pohon contoh, biomassa pohon dihitung dengan menggunakan konversi volume yang menggunakan berbagai kombinasi faktor bentuk, tinggi pohon, kerapatan kayu, dan nilai BEF. Estimasi biomassa ini kemudian dibandingkan dengan biomassa pohon aktual yang diperoleh dari pengambilan sampel destruktif. Hasil penelitian menunjukkan bahwa konversi volume menggunakan kombinasi antara tinggi pohon hingga diameter terkecil (Td), faktor bentuk absolut (fa), kerapatan kayu dari bor riap (KKb), dan referensi Nilai BEF (BEFp) memberikan estimasi biomassa pohon yang paling akurat. Dengan demikian, metode konversi volume dengan variabelvariabel tersebut dapat digunakan sebagai alternatif pendugaan biomassa pohon, khususnya di kawasan habilitasi HPGW.
Keyword: angka bentuk, biomassa, kerapatan kayu, pinus, tingkat ketelitian

Judul: Perbandingan Ketelitian Metode Pendugaan Biomassa Pinus dan Agathis di Areal Rehabilitasi Hutan Pendidikan Gunung Walat.
Abstrak: An alternative method for estimating biomass is converting tree volume into aboveground tree biomass by using wood density and biomass expansion factor (BEF). This method is commonly used in estimating a tree biomass, especially when allometric biomass models are not available. The objective of this study was to analyze the precision of biomass estimation using the conversion of tree volume for estimating tree-level and stand-level biomass in the rehabilitation area of Gunung Walat University Forest (HPGW). Tree biomass was calculated using three methods, i.e. allometric models, tree volume conversion using a general wood density, and tree volume conversion using a specific wood density. The results showed that generally the volume conversion method using a spescific wood density produced relatively similar biomass estimates to the allometric method. Thus, the volume conversion method using a specific wood density can be used as an alternative method for estimating stand biomass, especially in the rehabilitation area of HPGW.
Keyword: pine, agathis, biomass, volume conversion, precision

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