Judul: Struktur tegakan pasca penebangan pada sistem tebang pilih tanam jalur di konsesi hutan PT Erna Djuliawati
Abstrak: Forest harvesting causes the changes of forest ecosystem stability that can posses structure and species composition of forest stands. Stand structure is needed to show timber standing stock and describe stands regeneration ability. Stand structure can be described by the model of stand structure, there are family distribution and regression model. This research data was taken from the observation plot logged silviculture system of selective cutting and line planting of forest conditions based of post-logging at 12, 8, 6, 4, 2 years. This research aims to determine the model equations that can describe the timber standing stock in silviculture system of selective cutting and line planting and analyze the composition of the dominant species in natural regeneration. The results showed that the family distribution model of lognormal is the best model to describe the condition of stand structure in the area of PT Erna Djuliawati. The forest area has high preference of diversity index within species dominant at several species.
Keyword: Bogor Agricultural University (IPB), Silviculture System of Selective Cutting and Line Planting, Stand Structure Model, Family Distribution Model

Judul: Model Struktur Tegakan Pasca Penebangan dengan Sistem Silvikultur Tebang Pilih Tanam Jalur (Studi Kasus di PT. Erna Djuliawati, Kalimantan Tengah)
Abstrak: Kegiatan pemanfaatan hutan dapat mengakibatkan kerusakan pada tegakan yang tidak ditebang (tegakan tinggal). Tegakan bekas tebangan akan sangat sulit untuk kembali seperti hutan perawan karena akan banyak kerusakannya, baik fisik maupun non fisik. Kerusakan fisik hutan dapat dilihat dari struktur tajuk tegakan dan keterbukaan hutan yaitu struktur tegakan dan komposisi jenis. Tingkat kerusakan tegakan tinggal juga dipengaruhi oleh sistem silvikultur karena pada setiap sistem silvikultur akan berbeda permudaan dan limit diameter penebangannya. Untuk menerangkan kondisi struktur tegakan dapat menggunakan model-model famili sebaran seperti famili sebaran Lognormal, Gamma, Eksponensial negatif dan Weibull. Penelitian ini bertujuan untuk mengetahui dan mempelajari komposisi dan struktur tegakan tinggal pada sistem TPTJ serta mengetahui model famili sebaran terbaik yang dapat menggambarkan struktur tegakan tinggal. Hasil penelitian ini diharapkan dapat digunakan sebagai data dan informasi sebagai evaluasi kondisi tegakan tinggal di PT. Erna Djuliawati, Kalimantan Tengah. Penelitian ini dilaksanakan di PT. Erna Djuliawati, Kalimantan Tengah pada bulan Mei-Juni 2009. Data yang digunakan ialah data pengukuran diameter pohon dengan diameter ≥ 5 cm dan pengamatan terhadap tajuk pohon yang dilakukan pada areal kondisi 3 tahun, 4 tahun, dan 6 tahun setelah penebangan dengan sistem TPTJ dibuat petak contoh berukuran 100m x 100m (1ha) kemudian dibuat jalur contoh dengan ukuran 25m x 100m.
Keyword: 

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