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This study aims to determine and compare antioxidant activity, total phenolics, flavonoids, and the relationship of phenolic and total flavonoids with the antioxidant activity of the three kratom variants. The ethanol extract of the third variant of kratom leaves was obtained by maceration. Through the antioxidant activity test using DPPH method, all three extracts showed strong antioxidant activity with IC50 values of 26.39, 30.25, and 30.59 μg/mL. The relationship of total phenolics and flavonoids with antioxidant activity was determined by the Pearson correlation test. Examination of total phenolic content using the Folin-Ciocalteu method with successive results for green, red, and white kratom are 6.11, 8.67, and 9.09 mg GAE/g extract. Examination of total flavonoid content using the colorimetric method for green, red, and white kratom were 0.86, 0.68, and 1.13 mg QE/g extract, respectively. The total phenolic content and antioxidant activity showed a correlation coefficient value of -0.32 (P0.05), and the total flavonoid content to antioxidant activity showed a correlation coefficient value of 0.81 (P0.05). Thus, all three variants of kratom have potency as natural antioxidants, but their total phenolic and flavonoid content does not influence their antioxidant activity.

Penelitian ini dilakukan dengan tujuan menentukan tingkat kelayakan serta respon peserta didik mengenai media video pembelajaran animasi pada materi hidrokarbon. Metode penelitian yang diterapkan adalah Research and Development (RD) dengan model ADDIE mencakup tahap Analyze, Design dan Development . Subjek penelitian ini yaitu media pembelajaran video animasi pada materi hidrokarbon. Teknik pengumpulan data yang diterapkan adalah pengukuran dan komunikasi tidak langsung. Alat pengumpul data menggunakan lembar penilaian kelayakan dan angket respon yang diukur menggunakan skala likert. Penilaian kelayakan media pembelajaran video animasi pada materi hidrokarbon memperoleh hasil sangat layak dengan persentase 96,67% pada aspek materi dan 100% pada aspek media. Hasil uji respon peserta didik memperoleh hasil sangat baik dengan persentase pada uji coba perorangan, uji coba kelompok kecil dan uji coba lapangan berturut-turut sebesar 88,33%, 86,14% dan 89,57%. Dengan demikian, media pembelajaran video animasi pada materi hidrokarbon yang dihasilkan dapat diimplementasikan sebagai media pembelajaran tambahan pada materi hidrokarbon.

Kratom leaves are known as traditional medicine with various benefits, such as antibacterial, antimicrobial, and antioxidant properties. These benefits are attributed to the presence of secondary metabolites, particularly mitragynine. Mitragynine can be obtained through extraction methods. However, to date, no research has compared the efficiency of sonication, reflux, and soxhletation extraction methods on three variants of kratom leaves for obtaining mitragynine. This study aimed to compare the effectiveness of the extraction methods by extracting 15 grams of three variants of kratom leaves using the sonication, reflux, and soxhlet methods. Each extract obtained was quantitatively analyzed using a UV- Vis spectrophotometer to determine the amount of alkaloid and HPLC to determine the amount of mitragynine. The results indicate that the most efficient method for obtaining total alkaloid from the green variant (19.125 mg/g) is through sonication and reflux, the red variant (31,625 mg/g) and the white variant (26,125 mg/g) are through sonication. The most efficient method for obtaining mitragynine from green (22.21 mg/g) is sonication, from red (29.15 mg/g) is reflux, and from white (24.62 mg/g) is soxhletation. Overall, these data show that different extraction methods produce different levels of mitragynine in each kratom variant.

Penelitian bertujuan untuk menentukan bahan ajar berbasis android pada material tata nama yang ditentukan. Pengembangan bahan ajar android dapat memudahkan peserta didik mengakses materi secara praktis dan membantu pemahaman materi tata nama senyawa yang mungkin terjadi, serta diharapkan peserta didik dapat memanfaatkan teknologi informasi dalam hal belajar. Penelitian menggunakan metode penelitian dan pengembangan dengan model ADDIE. Teknik pengumpulan data menggunakan instrumen validasi dan angket respon. Analisis data secara deskriptif kualitatif.Hasil analisis menunjukan bahwa validasi aspek materi 91,39% dengan kriteria sangat layak, validasi aspek media 90% dengan kriteria sangat layak, validasi aspek bahasa 94,73% dengan kriteria sangat layak, angket respon guru kimia 93,75% dengan kriteria sangat layak . baik, respon peserta didik uji coba skala kecil diperoleh 89.32% dengan kriteria sangat baik serta hasil respon peserta didik uji coba skala meluas sebesar 89.45% dengan kriteria sangat baik. Dapat dikatakan bahwa bahan ajar berbasis android berupa aplikasi dengan kapasitas 42 MB yang dikembangkan dengan respon peserta didik yang baik dan respon guru yang sangat baik, sehingga bahan ajar tersebut sangat layak digunakan sebagai perangkat pembelajaran. Kata kunci: pengembangan; bahan terbuka; android; senyawa berbahaya

Schistosomiasis is a parasitic disease caused by Schistosoma worm infection. Some species of snails can serve as the intermediate hosts for the parasite. Numerous interventions have been performed to repress the snail population. One of them is the use of molluscicide. Nevertheless, it is debated that molluscicide intervention has negative impacts on the ecosystem. To investigate the impact of more environmentally friendly interventions, we develop a schistosomiasis model with treatment, habitat modification and biological control. The biological control agent examined in our model is a snail predator. Moreover, to investigate the impact of snail habitat modification, we assume that the snail population grows logistically. We show that all solutions of our model are non-negative and bounded. We also study the existence and stability conditions of equilibrium points. The basic reproduction numbers are determined using the next-generation operator. Linearization combined with the Routh-Hurwitz criterion is used to prove the local stability condition of disease-free equilibrium points. Bifurcation theory is applied to investigate the local stability condition of the endemic equilibrium points. To examine the global behavior of our model, we use asymptotically autonomous system theory and construct a Lyapunov function. We perform several numerical simulations to validate and support our deductive results. Our results show that early treatment can reduce the basic reproduction number and schistosomiasis cases. In addition, modifying snail habitat and releasing the snail predator at the snail habitat can reduce schistosomiasis prevalence. We suggest using snail predators which can hunt and kill snails effectively as a biological control agent.

Penelitian ini bertujuan untuk mengetahui ada tidaknya perbedaan hasil belajar pada model pembelajaran Numbered Heads Together pada mata pelajaran Hukum Kimia Dasar. Bentuk penelitian ini adalah rancangan eksperimen sejati. Sampel penelitian adalah kelas X TSM sebagai kelas eksperimen, kelas X TKR sebagai kelas kontrol dengan purposive sampling. Alat pengumpulan data yang digunakan terdiri dari tes hasil belajar, wawancara, dan lembar observasi. Hasil belajar dianalisis menggunakan uji Mann Whitney U. Hasil analisis menunjukkan bahwa terdapat perbedaan hasil belajar antara siswa yang diajar menggunakan LKPD model Numbered Heads Together dengan siswa yang diajar menggunakan metode konvensional. Pembelajaran dengan NHT berbantuan LKPD memiliki pengaruh sebesar 42,51% dengan kategori tinggi (Effect Size = 1,44) terhadap peningkatan hasil belajar siswa kelas X TSM SMK PGRI Pontianak pada materi hukum kimia dasar.

In this article, we consider a predator–prey interaction incorporating cannibalism, refuge, and memory effect. To involve the memory effect, we apply Caputo fractional-order derivative operator. We verify the non-negativity, existence, uniqueness, and boundedness of the model solution. We then analyze the local and global stability of the equilibrium points. We also investigate the existence of Hopf bifurcation. The model has four equilibrium points, i.e., the origin point, prey extinction point, predator extinction point, and coexistence point. The origin point is always unstable, while the other equilibrium points are conditionally locally asymptotically stable. The stability of the coexistence point depends on the order of the Caputo derivative, α. The prey extinction point, predator extinction point, and coexistence point are conditionally globally and asymptotically stable. There exists Hopf bifurcation of coexistence point with parameter α. The analytic results of stability properties and Hopf bifurcations are confirmed by numerical simulations.

The COVID-19 pandemic has changed the paradigm of the online learning process, which was originally running offline. As a result, facilities and infrastructure, such as practical guidebooks used to support implementing practical activities, must adapt to online conditions. Website-based technology-assisted practicum guides are the right strategy for online learning. In addition, learning activities on the practicum guide website use a contextual approach, such as the guided inquiry method, to train students to develop their critical and scientific thinking skills. However, the reality on the ground shows that the practicum guide used is not website-based, so it has not been able to support learning during the COVID-19 pandemic, and the learning model used has not used the guided inquiry method. This study aims to develop a guided inquiry-based biochemical practicum guide website on starch identification material and determine the feasibility of the website as well as student and lecturer responses to the developed website. This research is development research using the Borg and Gall model. Their research stages consist of needs analysis, planning, product draft development, initial field trials, revisions, field trials, and revisions. The practicum guide website was validated by 11 experts consisting of 2 language experts and three experts in IT, materials, and guided inquiry learning. They collect feasibility data and student and lecturer responses using indirect communication assisted by questionnaires. The feasibility test results of linguistics, IT, inquiry learning, and material experts obtained percentages of 88.3%, 85.5%, 90.5%, and 91.1%, respectively. All aspects show a very decent category. Student responses at the initial field test stage, main field, and lecturer were 85.7%, 88.3%, and 90%, respectively. All aspects of the feasibility test, student and lecturer responses are in the very feasible category. The results of this study indicate that the guided inquiry-based biochemical practicum guide website on starch identification material is very feasible to use. This practicum guide website is expected to help carry out a biochemistry practicum during the COVID-19 pandemic and improve students' thinking skills

This research was aimed to produce a valid electronic graphic novel on free radical reaction subject and to find out the student’s response to the developed product. This research employed Research Development (RD) method by using Thiagarajan’s 4D model with modification, in which applied only three of four steps in 4D model. The developed product was validated by experts. The responses toward developed product were collected from the students of Chemistry Education FKIP Untan who have taken organic chemistry course. Data collection tools used were validation sheets and student’s response questionnaires on the developed product. The validation’s result from the experts showed that the developed product was very proper in terms of content, presentation, linguistic, and graphic aspects with consecutive total scores of 94.0%, 95.0%, 89.0%, and 100,00% respectively. The results of the student’s responses in small group trials and in large group trials were of 82.5% with high category and of 83.2% with very high category, respectively. Thus, this electronic graphic novel on radical reaction has very good potential as a learning media to attract students to learn free radical reaction and its application in daily life.

This study discusses the dynamical analysis of the symbiosis commensalism and parasitism models in four populations with Michaelis-Menten type harvesting in the first commensal population. This model is formed from a construction of the symbiotic model of commensalism and parasitism by harvesting the commensal population. This construction is by adding a new population, namely the second commensal population. Furthermore, it will be investigated that the four populations can coexist. The first analysis is to identify the conditions of existence at all equilibrium points along with the conditions for their existence and local stability around the equilibrium point along with the stability requirements. From this model, it is obtained sixteen points of equilibrium, namely one point of extinction in the four populations, four points of extinction in all three populations, six points of extinction in both populations, four points of extinction in one population and one point where the four populations can coexist. Of the sixteen points, only four points can be asymptotically stable if they meet the stability conditions that have been determined. Finally, a numerical simulation is performed to describe the model behavior. In this study, the method used in numerical simulation is the RK-4 method. The numerical simulation results that have been obtained support the dynamical analysis results that have been carried out previously.

Dillenia suffruticosa is one of the tropical medicinal plants that has been used traditionally for treating several tropical diseases. However, phytochemical and pharmacological investigations of D. suffruticosa wood bark have not been well-investigated. This research aimed to investigate the correlation between antioxidant properties and total phenolic content of phenolics rich extract and fractions from D. suffruticosa wood bark. The phytochemical investigation revealed the existence of phenolics and alkaloids in methanolic crude wood bark extract and all fractions. Meanwhile, the presence of flavonoids was shown in chloroform and methanol fractions. The highest total phenolic content was demonstrated by methanol fraction with 254.34 ± 16.86 mg GAE/g extract. Meanwhile, the highest total flavonoid content was interestingly displayed in chloroform fraction with 15.33 ± 0.26 mg RE/g extract. The crude extract and methanol fraction had a profound antioxidant activity with IC50 values of less than 15.63 ppm and 8.83 ppm, respectively. A strong correlation was shown between the antioxidant activity and total phenolic contents through correlation analysis. Thus, the D. suffruticosa wood bark could be considered a potential natural source of antioxidants.

This article discussed about a dynamic analysis of the symbiotic model of commensalism and parasitism with harvesting in the commensal population. This model is obtained from a modification of the symbiosis commensalism model. This modification is by adding a new population, namely the parasite population. Furthermore, it will be investigated that the three populations can coexist. The analysis carried out includes the determination of all equilibrium points along with their existence and local stability along with their stability requirements. From this model, it is obtained eight equilibrium points, namely three population extinction points, two population extinction points, one population extinction point and three extinction points can coexist. Of the eight points, only two points are asymptotically stable if they meet certain conditions. Next, a numerical simulation will be performed to illustrate the model’s behavior. In this article, a numerical simulation was carried out using the RK-4 method. The simulation results obtained support the results of the dynamic analysis that has been done previously.

Pada penelitian ini dibahas suatu model yang menggambarkan perubahan konsentrasi aflatoksin pada tanaman, hewan, dan manusia, yang menyebar melalui makanan dan pakan ternak yang berasal dari tanaman. Pada model yang berupa sistem autonomus ini dilakukan analisis dinamik yang meliputi penentuan titik kesetimbangan, syarat eksistensi titik kesetimbangan, angka reproduksi dasar, dan analisis kestabilan lokal titik kesetimbangan. Hasil analisis dinamik menunjukkan bahwa model memiliki empat titik kesetimbangan dan dua angka reproduksi dasar. Tiga titik kesetimbangan eksis dengan syarat tertentu. Kestabilan titik kesetimbangan aksial bergantung pada angka reproduksi dasar, sedangkan titik kesetimbangan interior selalu stabil asimtotik lokal bila ia eksis. Hasil simulasi numerik yang dilakukan mendukung hasil analisis dinamik.

Hanjuang, mangosteen, putat, and tabelian plants are used by people of Lanjak deras Village as natural dyes for woven cloth and food so that they can be used as an alternative substitute synthesis indicators that are limited in a remote area. The purpose of the study is to determine the best type of solvent in extracting the samples, pH range, UV spectrum profiles, precision, and accuracy of the plant's extract as indicator. The sample was the plants that are used by the people of West Borneo as natural dyes, namely putat flower, tebelian stem, mangosteen leave, and hanjuang leave. Each sample was macerated with four types of solvents, namely aquadest, ethanol, methanol, and (1:1) ethanol:methanol, then the extract was testing by pH range. The extracts providing color changes were determined for its UV-Vis spectrum profile, stability, accuracy, and precision. The results showed that ethanol and methanol were suitable for extracting mangosteen leaves, methanol for putat flowers, ethanol for hanjuang leaves, and (1: 1) ethanol:methanol for tebelian stems. Mangosteen leaf extract, putat flower, and tebelian stem gave a pH range of 12-14, while hanjuang leaf extract did not change color. The phytochemical test results and UV spectrum profile of mangosteen leaf extract, putat flower, and tebelian stem indicated the presence of phenolic compounds. The powder and extract solution had high stability. Mangosteen leaf extract, putat flower, and tebelian stem had precision and accuracy with the medium category. These data indicated that mangosteen leaf extract, putat flower, and tebelian stem have potential as indicators of acid-base.

Cytotoxic activities of extracts of Pycnarrhena cauliflora leaves, stems and roots on some human cancer cells have been known. However, the cytotoxicity of stem of Pycnarrhena cauliflora on human breast cancer cell line T47D through an apoptosis induction has not been proven yet. This study was an effort in understanding the cytotoxic activity of stem of Pycnarrhena cauliflora through apoptosis induction. The crude ethanol extract was partitioned between n-hexane and dichloromethane at pH 3, 7 and 9, which was subsequently tested for their cytotoxic activity against human breast cancer cell line T47D by using 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT). Flow cytometric analysis with Annexin V-FLUOS/ propidium iodide (PI) double staining was used for apoptosis analysis. The dichloromethane fraction at pH 7 was considered the most potent with an IC50 value of 59.30 µg/mL and induced apoptosis on the T47D cell line. The result indicated the potential of dichloromethane fraction of the stem of P.cauliflora as a source of bioactive compounds and provided a basis of further studies to isolate a new anticancer compound.

In this paper, a dynamical analysis of a fractional-order predator-prey model with infectious diseases in prey is performed. First, we prove the existence, uniqueness, non-negativity, and boundedness of the solution. We also show that the model has at most five equilibrium points, namely the origin, the infected prey and predator extinction point, the infected prey extinction point, the predator extinction point, and the co-existence point. For the first four equilibrium points, we show that the local stability properties of the fractional-order system are the same as the first-order system, but for the co-existence point, we have different local stability properties.We also present the global stability of each equilibrium points except for the origin point. We observe an interesting phenomenon, namely the occurrence of Hopf bifurcation around the co-existence equilibrium point driven by the order of fractional derivative. Moreover, we show some numerical simulations based on a predictor-corrector scheme to illustrate the result of our dynamical analysis.

Abstract The people in Rasau Jaya Umum village Kubu Raya regency have used plants as ingredient food that has been inherited from generation to generation for daily cooking or to make the typical food. The typical food in Rasau Jaya Umum village like Rengginang, crackers, and salted fish. The purpose of research to collect data of plants used as food additives by people in Rasau Jaya Umum village. The respondents were chosen through snowball sampling technique and then given a series of questions using observation sheet. The head in Rasau Jaya Umum village is chosen as the main respondent then proceeded to the traders and home industry owners who produce the typical food. The results showed that there are 18 species of 15 plant families used as natural additives, namely Liliaceae, Zingiberaceae, Amaranthaceae, Oxalidaceae, Rutaceae, Arecaceae, Poaceae, Gnetaceae, Malvaceae, Cactaceae, Pandanaceae, Piperaceae, Polygonaceae, Anacardiaceae, and Myrtaceae. Keywords: plants, food additives, Rasau Jaya Umum village

We consider a mathematical model to describe the interaction between predator and prey that includes predator cannibalism and refuge. We aim to study the dynamics and its long-term behavior of the proposed model, as well as to discuss the effects of crucial parameters associated with the model. We first show the boundedness and positivity of the solution of the model. Then, we study the existence and stability of all possible equilibrium points. The local stability of the model around each equilibrium point is studied via the linearized system, while the global stability is performed by defining a Lyapunov function. The model has four equilibrium points. It is found that the equilibrium point representing the extinction of both prey and predator populations is always unstable, while the other equilibrium points are conditionally stable. In addition, there is forward bifurcation phenomena that occur under certain condition. To support our analytical findings, we perform some numerical simulations.

This study aims to determine and compare antioxidant activity, total phenolics, flavonoids, and the relationship of phenolic and total flavonoids with the antioxidant activity of the three kratom variants. The ethanol extract of the third variant of kratom leaves was obtained by maceration. Through the antioxidant activity test using DPPH method, all three extracts showed strong antioxidant activity with IC50 values of 26.39, 30.25, and 30.59 µg/mL. The relationship of total phenolics and flavonoids with antioxidant activity was determined by the Pearson correlation test. Examination of total phenolic content using the Folin-Ciocalteu method with successive results for green, red, and white kratom are 6.11, 8.67, and 9.09 mg GAE/g extract. Examination of total flavonoid content using the colorimetric method for green, red, and white kratom were 0.86, 0.68, and 1.13 mg QE/g extract, respectively. The total phenolic content and antioxidant activity showed a correlation coefficient value of -0.32 (P>0.05), and the total flavonoid content to antioxidant activity showed a correlation coefficient value of 0.81 (P>0.05). Thus, all three variants of kratom have potency as natural antioxidants, but their total phenolic and flavonoid content does not influence their antioxidant activity. [ABSTRACT FROM AUTHOR]

Schistosomiasis is a parasitic disease caused by the schistosoma worm. A snail can act as the intermediate host for the parasite. Snail-population control is considered to be an effective way to control schistosomiasis spread. In this paper, we discuss the schistosomiasis model incorporating a snail predator as a biological control agent. We prove that the solutions of the model are non-negative and bounded. The existence condition of equilibrium points is investigated. We determine the basic reproduction number when the predator goes to extinction and when the predator survives. The local stability condition of disease-free equilibrium point is proved using linearization, and the Lienard–Chipart and Routh–Hurwitz criteria. We use center-manifold theory to prove the local stability condition of the endemic equilibrium points. Furthermore, we constructed a Lyapunov function to investigate the global stability condition of the disease-free equilibrium points. To support the analytical results, we presented some numerical simulation results. Our findings suggest that a snail predator as a biological control agent can reduce schistosomiasis prevalence. Moreover, the snail-predator birth rate plays an essential role in controlling schistosomiasis spread.

All this time, mathematics has become the scourge for elementary and junior high school students, so that students are not well motivated to learn the material of Mathematics. Along with the development of computer technology, it can be used as one tool that can help the learning process. Mathematics software can be used to explain the difficult concepts in mathematics becomes easily, clearer, more interesting and fun. In Ponorogo, mathematics teachers have a meeting forum called the Subject Teacher Council (MGMP) of Mathematics. The general problems of the council is the less equality in opportunities of MGMP Mathematics teachers in Junior Secondary Schools (SMP and MTs) at Ponorogo to attain trainings for improving students skills in understanding the material of Mathematics and the limited insight of mathematics teachers about mathematics software that can be used as an instructional media of mathematics material. Therefore, the activity of microsoft mathematics training for mathematics teachers in Junior Secondary Schools at Ponorogo has been necessarily and urgently needed to improve the quality of learning methods. These software is open source software with less space requirement in the computer and easy installation.

This paper discusses a dynamical analysis on a model that governs the growth of tumour cell under a therapy by using oncolytic viruses, on the standard incident rate. The model is a modification of the similar one by replacing the bilinear incident rate with the standard one. The conducted dynamical analysis consists of the determination of equilibrium points and their existence conditions, followed by local as well as global stability analysis of the equilibrium points. The analytical result shows that there are two equilibrium points, namely uninfected and the endemic point, which needs a condition to exist. Stability analysis shows that there is a dimensionless basic reproduction number that marks the existence as well as the stability of equilibrium points. When basic reproduction number is less than one, there is only the uninfected equilibrium, which is global asymptotically stable. On the other hands, both of equilibrium points exist when the basic reproduction number is more than one, but the uninfected point is not stable anymore, while the endemic one is local asymptotically stable under a condition. Some numerical simulations are performed to illustrate the analytical result. Numerically, it can also be demonstrated that there is a set of parameters which indicates that tumour can be fully removed.