Judul: Pemodelan Waktu Hilangnya Penglihatan Penderita Diabetic  Retinopathy dengan Model Cox Frailty
Abstrak: Diabetic retinopathy adalah kondisi di mana pembuluh darah pada mata bengkak dan bocor karena kadar gula dalam darah terlalu tinggi. Penderita diabetic retinopathy berpotensi kehilangan penglihatannya karena darah yang bocor ke dalam bola mata akan menghalangi cahaya untuk masuk ke retina. Model Cox adalah model survival yang mampu memodelkan pengaruh kovariat terhadap waktu ketahanan. Konsekuensi dari bentuk model Cox adalah asumsi proportional hazard, yaitu dua buah amatan akan memiliki hazard ratio yang selalu sama sepanjang waktu. Model frailty mampu memodelkan pengaruh acak tak termati yang memengaruhi waktu survival amatan. Model Cox dengan frailty adalah gabungan dari model Cox dan model frailty. Kovariat yang secara signifikan memengaruhi waktu ketahanan penglihatan penderita adalah laser, risk dan eye. Kita juga mendapatkan bukti kuat bahwa pengaruh frailty pada waktu ketahanan penglihatan penderita adalah signifikan. Pada penelitian ini digunakan frailty yang menyebar sebaran Gamma. Model Cox dengan frailty ternyata mampu menjelaskan waktu ketahanan dengan lebih baik daripada model Cox. Hal ini terlihat dari nilai log likelihood model Cox dengan frailty yang lebih besar daripada model Cox., Diabetic Retinopathy is a condition where blood vessels in the eye swell and leak due to high blood sugar level. Patients can lose their vision because the leaked blood prevents light from reaching the retina. The Cox model is a semiparametric survival model that is able to model the effect of covariates to the survival time. The consequence of the form of the model is that the assumption of proportional hazard, that is, the hazard ratio of two given observations will be the same at all time. The frailty model can model the unobserved random effect that influences the survival time. The Cox frailty model is a combination of the Cox model and the frailty model. Significant covariates for the survival time of vision are laser, trt, risk and eye. We obtain substantial evidence that the frailty does affect the survival time. In this research we use the gamma frailty. The Cox frailty model can explain the survival time better than the Cox model. This can be seen from the fact that it has higher log likelihood than the Cox model.
Keyword: diabetic retinopathy, log likelihood, model Cox dengan frailty, proportional hazard

Judul: Modeling Analysis of the Survival of  Diabetes Mellitus Patients using Cox Proportional Hazard and Random Survival  Forest
Abstrak: Diabetes melitus merupakan salah satu penyakit serius dan perlu perhatian dari setiap individu. Tercatat jumlah penderita akibat diabetes melitus di Indonesia menempati posisi kelima tertinggi di dunia. Badan Penyelenggara Jaminan Sosial (BPJS) Kesehatan merupakan suatu badan asuransi yang terbuka untuk mencakup kesehatan seluruh masyarakat Indonesia. Biaya kesehatan yang dibayarkan BPJS Kesehatan untuk penyakit diabetes melitus sangat tinggi dan terus mengalami peningkatan. Cox Proportional Hazard (CPH) merupakan metode semiparametrik dalam pemodelan analisis daya tahan yang memiliki asumsi keproporsionalitasan laju bahaya sesaat harus konstan pada rentang pengamatan. Berbeda dengan CPH, Random Survival Forest (RSF) merupakan metode nonparametrik dalam melakukan pemodelan analisis daya tahan berdasarkan pohon keputusan. Model RSF tidak memerlukan asumsi dalam melakukan pemodelan, sehingga menjadi salah satu kelebihan dalam pemodelan analisis daya tahan. Berdasarkan hasil penelitian pada kasus diabetes melitus, model RSF sedikit lebih unggul dibandingkan dengan CPH berdasarkan metrik akurasi C-Index, Brier score, dan C/D AUC Index. Model RSF memiliki skor C-Index sebesar 0,847, Brier score 0,113 dan C/D AUC Index 0,766. Model CPH memiliki skor C-Index sebesar 0,711, Brier score 0,142 dan C/D AUC Index 0,640. Peubah penting pada kasus kematian akibat diabetes melitus adalah usia, diagnosis(ICD10), kelas peserta dan kelas rawat peserta BPJS Kesehatan., Diabetes mellitus is one of the serious diseases that requires attention from every individual. The number of diabetes mellitus sufferers in Indonesia ranks fifth highest in the world. The Social Security Administration (BPJS) Health Insurance is an insurance body open to covering the health of all Indonesian citizens. The healthcare costs paid by BPJS Health for diabetes mellitus are very high and continue to increase. The Cox Proportional Hazard (CPH) is a semiparametric method in survival analysis modeling that assumes the proportionality of the instantaneous hazard rate must remain constant over the observation period. Unlike CPH, the Random Survival Forest (RSF) is a nonparametric method for survival analysis modeling based on decision trees. The RSF model does not require assumptions in modeling, which is one of its advantages in survival analysis modeling. Based on research on diabetes mellitus cases, the RSF model slightly outperforms the CPH model according to the accuracy metrics of C Index, Brier score, and C/D AUC Index. The RSF model has a C-Index score of 0.847, a Brier score of 0.113, and a C/D AUC Index of 0.766. The CPH model has a C-Index score of 0.711, a Brier score of 0.142, and a C/D AUC Index of 0.640. Feature importance in cases of death due to diabetes mellitus are age, diagnosis (ICD10), membership class, and the inpatient class of BPJS Health participants.
Keyword: BPJS Kesehatan, cox proportional hazard, diabetes mellitus, random survival forest

Judul: Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana), Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana
Abstrak: I reevaluated taxonomic of subgenus Papurana position from Halmahera based on morphological and molecular analyses. My results show that two separate species occur on the Halmahera Island, each nested within two distinct clades (hereafter papua clade and celebensis clade), one of which corresponds to H. moluccana (celebensis clade) and the other to an unidentified species (papua clade). By p-distance ranging from 6.9 to 11.5% on the 16S rRNA gene, the unidentified species (Hylarana sp.) is genetically different from all congeners of the papua clade. The Hylarana sp. can be distinguished from all congeners by following combination of charactes: vomer teeth in two oblique rows with narrow inter-vomer distance; snout rounded dorsally; dorsum with few scattered cone-shaped tubercles that are black with white tips; distinct skin folds (ridges) on the dorsal side of the thigh coinciding with dark brown cross bars; a marbled pattern on the ventral side of the thigh and yellowish groin. I also present new data for H. daemeli, H. volkerjane, and H. arfaki from the western region of Papua. Furthermore, I found that H. celebensis has numerous mtDNA lineages, indicating cryptic diversity within the celebensis clade. The discovery of two separate species on Halmahera necessitates more research into the biogeographic history of Hylarana in Northern Moluccas.
Keyword: frog, Halmahera, Hylarana, morphology, Papurana, phylogenetic