Judul: Hydraulic Conductivity of Xylem Vessels in Peatland Vegetation Roots
Abstrak: Indonesia merupakan negara yang memiliki lahan gambut yang luas. Vegetasi yang tumbuh di lahan gambut diduga mempunyai kemampuan adaptasi pada cekaman genangan. Salah satu cara mengetahui kemampuan adaptasi ialah dengan menganalisis kemampuan pembuluh xilem mentransportasikan air dari akar menuju tajuk yang disebut dengan konduktivitas hidrolik pembuluh xilem. Adanya genangan air di lahan gambut menyebabkan konduktivitas hidrolik pembuluh xilem akar menyesuaikan dengan ketersediaan air di lahan tersebut. Penelitian ini bertujuan menganalisis keragaman konduktivitas hidrolik pembuluh xilem akar dan menganalisis hubungan nilai konduktivitas hidrolik pembuluh xilem akar dengan karakter pembuluh xilem akar dari 145 spesies vegetasi lahan gambut. Metode yang digunakan untuk penelitian ini adalah pembuatan sayatan melintang akar dan bioimaging untuk menentukan konduktivitas hidrolik dan karakteristik pembuluh xilem sampel akar. Hasil penelitian menunjukkan bahwa konduktivitas hidrolik pembuluh xilem seluruh sampel akar vegetasi lahan gambut memiliki keragaman luas, berkisar antara 1,691 – 315,670 kg m?¹ MPa?¹ dt?¹. Konduktivitas hidrolik pembuluh xilem berkorelasi positif dengan total luas lumen pada area xilem dan berkorelasi negatif dengan kerapatan pembuluh xilem., Indonesia has extensive peatland areas. Vegetation that grows in peatland areas is presumed to have the ability to adapt flooding stress. The method for assessing adaptive abilities involves analyzing the xylem vessel capacity to transport water from the roots to the shoot of tree, known as hydraulic conductivity. The water logging conditions in peatlands induce an adaptive response in the xylem of roots, aligning it with the water availability in these environments. This study aims to analyze the diversity of hydraulic conductivity in root xylem and to investigate the relationship between the hydraulic conductivity of root xylem vessels and the characteristics of root xylem vessels from 145 vegetation species. This study uses cross-section of roots and bioimaging to determine hydraulic conductivity and xylem characteristics of root samples. As a result, the hydraulic conductivity of the xylem shows high diversity among all the root samples. The index of hydraulic conductivity ranges from 1,691 to 315,670 kg m?¹ MPa?¹ s?¹. Hydraulic conductivity has a positive correlation with total lumen area and a negative correlation with vessel density.
Keyword: bioimaging, hydraulic conductivity, lumen area, peatland, vessel density

Judul: Hydraulic Conductivity of Stem Xylem Vessels in Peatland Vegetation
Abstrak: Lahan gambut seringkali mengalami genangan dengan pH tanah gambut yang rendah. Kondisi seperti ini menjadi faktor pembatas untuk tumbuhan yang dapat tumbuh di lahan tersebut. Adaptasi tumbuhan pada lahan gambut, khususnya pada kondisi genangan perlu dipelajari dalam menentukan strategi pemanfaatan lahan yang lebih baik. Salah satu aspek yang dapat digunakan sebagai penentu kemampuan tumbuhan di lahan gambut ialah konduktivitas hidrolik potensial (Kp) pembuluh xilem. Analisis Kp pembuluh xilem batang vegetasi lahan gambut belum pernah dilakukan. Penelitian ini bertujuan menganalisis sebaran Kp pembuluh xilem batang tumbuhan yang tumbuh di lahan gambut. Penghitungan Kp pembuluh xilem batang berdasarkan persamaan Hagen-Poiseuille dilakukan pada 146 spesies tumbuhan lahan gambut. Hasil menunjukkan bahwa nilai Kp pada xilem batang vegetasi lahan gambut berkisar antara 0,91–489,63 kg m-1 MPa-1 dt-1 dengan rata-rata 40,63 ± 9,20 kg m-1 MPa-1 dt-1. Nilai Kp pembuluh xilem batang terendah ditemukan pada spesies Diospyros bangkana dan tertinggi pada Alstonia angustiloba. Nilai Kp pembuluh xilem batang pada vegetasi lahan gambut memiliki hubungan positif kuat dengan rasio luas lumen terhadap luas xilem (Al:Ax) ¬¬yang dipengaruhi oleh jumlah dan kerapatan pembuluh xilem., Peatlands are often characterized by low-pH peat soils. This condition acts as a limiting factor for plants in this environment. Plant adaptation to peatlands, especially under stress conditions, needs to be studied to determine a better land use strategy. One aspect that can be used to assess the ability of plants to survive in peatlands is the potential hydraulic conductivity (Kp) of xylem vessels. Analysis of the Kp of stem xylem vessels in peatland vegetation has not been conducted previously. This study aims to analyze the distribution of Kp values within xylem vessels of various plant species growing on peatlands. The calculation of Kp based on the Hagen-Poiseuille equation, was applied to 146 peatland plant species. The results revealed a range of Kp values in the stem xylem of peatland vegetation, 0,91–489,63 kg m-1 MPa-1 s-1 with an average of 40,63 ± 9,20 kg m-1 MPa-1 s-1. The lowest Kp value of stem xylem vessels was found in the Diospyros bangkana, while the highest was in Alstonia angustiloba. The Kp value of stem xylem vessels in peatland vegetation exhibited a strong positive correlation with the lumen-to-sapwood area (Al:Ax), influenced by the number and density of xylem vessels.
Keyword: adaptasi tumbuhan, Alstonia angustiloba, Diospyros bangkana, luas lumen, plant adaptation, lumen-to-sapwood area

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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