This article aims to study the dynamics of a Lotka-Volterra predator-prey model with Allee effect in predator. According to the biological condition, the Caputo fractional-order derivative is chosen as its operator. The analysis is started by identifying the existence, uniqueness, and non-negativity of the solution. Furthermore, the existence of equilibrium points and their stability is investigated. It has shown that the model has two equilibrium points namely both populations extinction point which is always a saddle point, and a conditionally stable co-existence point, both locally and globally. One of the interesting phenomena is the occurrence of Hopf bifurcation driven by the order of derivative. Finally, the numerical simulations are given to validate previous theoretical results.

<span>This paper aims to analyze the scientific trend of research on Technological Pedagogical Content Knowledge (TPACK) through bibliometric study and explore how the contribution of Indonesian researchers in the Scopus database from 2015 to 2019. The sample was composed of 2075 documents in total. The results revealed that scientific publication on TPACK has been increasing. United States contributed the most documents on TPACK as well as Singapore’s institutions dominated in this area. Meanwhile, Indonesia put its two representative’s institutions: Universitas Sebelas Maret and Universitas Pendidikan Indonesia, among the big ten institutions in the world. All Indonesian documents produced by teacher-producing universities and public universities. United States and Taiwan have also contributed to the most productive authors of TPACK. Then, the visualization of research trend on TPACK resulted in four major clusters: i) TPACK as a system; ii) TPACK in relating to its scale; iii) TPACK in connecting with quantitative parameters; and iv) TPACK under beliefs, intention, and technology acceptance. The research findings could aid related researchers to recognize the trend of TPACK research and recommend directions for further research.</span>

This research focuses on the dynamical of a Leslie-Gower predator-prey model with competition on predator populations. The model represents an interaction between one prey and two predator populations. The analysis shows that there are four equilibrium points, namely the extinction of predator populations point, the extinction of the first predator population point, the extinction of the second predator and the interior point. The existence of the interior equilibrium point is investigated by using Cardan criteria. Local stability analysis shows that both predator populations have never been extinct together. The second and third equilibrium point is local asymptotically stable under some conditions. Numerical simulations are carried out to investigate the stability of the interior point as well as to show that more than one equilibrium point may be asymptotically stable together for a set of parameter.

This article discusses the one-prey, one-predator, and the super predator model with different types of functional response. The rate of prey consumption by the predator follows Holling type I functional response and the rate of predator consumption by the super predator follows Holling type II functional response. We identify the existence and stability of critical points and obtain that the extinction of all population points is always unstable, and the other two are conditionally stable i.e., the super predator extinction point and the co-existence point. Furthermore, we give the numerical simulations to describe the bifurcation diagram and phase portraits of the model. The bifurcation diagram is obtained by varying the parameter of the conversion rate of predator biomass into a new super-predator which gives forward and Hopf bifurcation. The forward bifurcation occurs around the super predator extinction point while Hopf bifurcation occurs around the interior of the model. Based on the terms of existence and numerical simulation, we confirm that the conversion rate of predator biomass into a new super-predator controls the dynamics of the system and maintains the existence of predator.

Abstrak JOURNAL NERS AND MIDWIFERY INDONESIA PENDAHULUANRemaja adalah suatu masa dimana individu berkembang dari saat pertama kali ia menunjukkan tanda-tanda seksual sekundernya sampai saat ia mencapai kematangan seksual, individu mengalami perkembangan psikologi dan pola identifikasi dari kanak-kanak sampai dewasa(1). Pada usia 10-19 tahun kondisi emosional remaja masih labil dan rentan terhadap pengaruh apapun, sehingga pada remaja sering terjadi perilaku seks bebas(2). Seks bebas berkembang dari suatu budaya Barat yang menekankan pada kebebasan, seperti bebas melakukan hubungan seksual sebelum menikah, bebas berganti-ganti pasangan, dan bebas melakukan hubungan seksual usia dini(3).Responden wanita dan pria berusia 15-19 tahun yang menyatakan bahwa gairah seks meningkat adalah tanda perubahan fisik pada remaja. Pengetahuan remaja umur 15-24 tahun tentang masa subur hanya 26% wanita dan 21% pria yang memberi jawaban benar tentang kesempatan terbesar seorang wanita menjadi hamil pada pertengahan siklus haid. Sebesar 74,1% wanita dan 70% pria usia 15-19 tahun tidak mengetahui gejala Infeksi Menular Seksual(4). Hal ini memberikan bukti rendahnya pengetahuan remaja tentang kesehatan reproduksi remaja.Data Pusat Studi Seksualitas (PSS) PKBI DIY tahun 2008 menemukan fakta bahwa remaja melakukan perilaku seksual berpelukan dalam pacaran 62,1%, bergandengan tangan 60,5%,

We study the dynamics of a modified Leslie–Gower one prey–two predators model with competition between predator populations. The model describes complex dynamics in the permanence, global stability and bifurcation. It is shown that there are eight possible equilibrium states. Two equilibrium states, i.e., the extinction of all of the species state and the extinction of both predators state are always unstable, while the other equilibrium states are conditionally locally and globally asymptotically stable. We also analyzed numerically the effect of competition between predators. Our numerical simulations showed that the competition rate of the second-predator may induce the transcritical bifurcation, the saddle-node bifurcation as well as the bi-stability phenomenon. Such numerical results are consistent with the analytical results.

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Bawang putih mengandung beberapa zat yang bermanfaat bagi kesehatan manusia, salah satunya yaitu senyawa fenol. Senyawa fenol pada bawang putih memiliki peranan penting sebagai zat antibakteri yang dapat diproses selanjutnya sebagai agen antibiofouling membran. Metode ekstraksi yang tepat seperti kombinasi Microwave-Assisted Extraction (MAE) dan maserasi digunakan untuk mendapatkan senyawa fenol pada bawang putih. Namun demikian variasi rasio bahan dan pelarut serta lama waktu ekstraksi yang sesuai perlu diperhatikan dengan menggunakan kombinasi metode tersebut. Oleh karena itu tujuan penelitian ini yaitu mendapatkan ekstrak fenol dari bawang putih dengan variasi perlakuan rasio bahan dan pelarut serta lama waktu ekstraksi. Hasil ekstrak fenol kemudian dianalisis menggunakan ANOVA dan uji lanjut BNT. Selain itu penelitian ini juga melakukan karakterisasi hasil ekstrak fenol dengan FTIR untuk mengetahui gugus fungsi yang ada pada ektrak secara kualitatif dan PSA melakukan pengujian ukuran ekstrak fenol bawang putih. Berdasarkan hasil yang diperoleh, total fenol tertinggi sebesar 9,94±0,85 mg GAE/g berat kering dapat diperoleh dengan rasio pelarut 1:8 (b/v) dan waktu ekstraksi selama 2 menit. Berdasarkan analisis FTIR, ekstrak kering terdiri dari kelompok alkohol, sehingga dapat membuktikan secara kualitatif bahwa ekstrak tersebut memiliki senyawa fenol. Berdasarkan pengukuran dengan PSA, hasil ekstrak senyawa fenol bawang putih memiliki ukuran partikel sebesar 72,08±4,55 nm yang selanjutnya dapat digunakan sebagai agen pencegahan biofouling pada membran dengan tipe mixed matrix.