Judul: Efektivitas Promosi Melalui Twitter pada Perusahaan Pariwisata Bahari “Ibu Penyu”
Abstrak: Promotion via twitter performed by Travel Agents "Ibu Penyu" to marketing their service. In addition, the promotion was also made to introduce marine tourism in Indonesia. Twitter presence is considered as one of the media for nautical tourism company in expanding economic activity. The purpose of this research are to analyze the characteristics of respondents and promotional activities, analyze the effectiveness of the promotion via twitter and analyze the correlation between the characteristics of the respondents and the effectiveness of promotional activities through the promotion of marine tourism company twitter "Ibu Penyu". The method used in data collection is via an online questionnaire that was distributed to the followers @ibupenyu. Data were analyzed using Spearman-rank correlation test and chi-square difference test. The results in this study are twitter effective of the promotion. Factors related to the effectiveness of the promotion is age, education level, income level, the frequency of feedback messages, rate the attractiveness of the message, and clarity in the delivery of information.
Keyword: Bogor Agricultural University, effectiveness, promotion, nautical

Judul: The The Effectiviess of Instagram as a Media for Promoting  Menganti Beach Tourism
Abstrak: Pengelola wisata Pantai Menganti memilih menggunakan instagram dalam melakukan kegiatan promosinya. Penggunaan media sosial instagram dipilih karena instagram merupakan salah satu media sosial yang sangat populer di kalangan masyarakat. Tujuan penelitian adalah menganalisis efektivitas instagram sebagai media promosi, menganalisis hubungan karakteristik followers dengan tingkat keterdedahan media sosial pada akun instagram @mengantikebumen, dan menganalisis hubungan tingkat keterdedahan media sosial instagram dengan efektivitas media promosi. Responden penelitian sebanyak 70 responden merupakan followers @mengantikebumen. Teknik pengumpulan data melalui kuisioner online yang disebar ke followers instagram @mengantikebumen melalui direct message. Data dianalisis menggunakan uji korelasi rank Spearman dan ChiSquare. Hasil penelitian menunjukkan penggunaan media sosial instagram sebagai media promosi efektif dalam memengaruhi perhatian (attention), ketertarikan (interest), dan rasa ingin tahu (search) dari followers instagram. Hasil penelitian menunjukkan bahwa tidak terdapat hubungan nyata antara karakteristik followers dengan keterdedahan media sosial. Hasil penelitian juga menunjukkan bahwa keterdedahan media sosial memiliki hubungan nyata dengan efektivitas instagram.
Keyword: effectivitness, instagram, promotion, social media

Judul: Mathematical model of Hematopoietic Stem Cell in Chronic Myelogenous Leukemia with and without Therapy
Abstrak: Leukemia or blood cancer is a diverse group of neoplastic disease, characterized by the multiplication of abnormal leukocytes or malignant transformation of blood-forming cells in bone marrow and lymphoid tissues. One of the most common types of leukemia is Chronic Myelogenous Leukemia (CML), which is usually diagnosed by the presence of certain chromosomal abnormalities, the so-called Philadelphia chromosome (Ph). One of the treatments of CML is Granulocyte Colony-Stimulating Factor (G-CSF). In this paper, we discuss two Hematopoietic Stem Cell (HSC) models, i.e. HSC without treatment and HSC with G-CSF treatment. The model of HSC without treatment included three equations representing the dynamics of HSC, leukocyte and platelet. Whereas, the model of HSC with G-CSF treatment includes the previous three equations and adds two more equations representing G-CSF injection and G-CSF circulation. The stability behavior of the system approaching the equilibrium points in the simulation study is carried out using Mathematica 7.0. The simulation results show that the G-CSF treatment can successfully decrease the number of HSC, which means reducing the CML.
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