Judul: Peranan hormon dan induksi ovulasi pada unggas
Abstrak: Hormon ovarium yang berperan dalam pengaturan sekresi gonadotropin dan siklus ovulasi adalah hormon Progesteron dan Estrogen. Kedua hormon itu secara menyolok meningkat dalam plasma darah menjelang ovulasi, kemudian turun ke keadaan normal pada saat ovulasi, kecuali estrogen yang masih tampak tinggi beberapa jam setelah ovulasi. Progesteron yang meninggi sebelum ovulasi tersebut merangsang hipotalamus yang selanjutnya mempengaruhi hipofisa untuk menghasilkan hormon-hormon gonadotropin yang penting dalam pembentukan telur dan ovulasi. Jadi dalam hal ini progesteron memberikan effek positif feedback terhadap pelepasan hormon gonadotropin. Estrogen juga dihasilkan di ovarium, dan konsentrasi- nya meningkat menjelang ovulasi sampai beberapa jam setelah ovulasi. Estrogen bersama progesteron mempunyai effek positif feedback terhadap pelepasan hormon gonadotropin men- jelang ovulasi, tetapi jika hanya estrogen effek positif feedback tidak terjadi. ...
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Judul: Pengaruh Gonadotropin Releasing Hormone (GnRH) Terhadap Produktivitas, Siklus Bertelur Dan Biometri Organ Reproduksi Serta Hubungannya Dengan Konsentrasi Progesteron Serum Ayam Lokal (Gallus domesticus)
Abstrak: This experiment was conducted to study the effect of Gonadotropin Releasing Hormone (GnRH) on productivity, egg laying cycle of the domestic fowl (Gallus domesticus) and its effect on serom Progesterone concentration, number of growing follicles and weight of the ovary, oviduct and biometry of the reproductve organs. Ten rna/lire female hens were used in this research. These hens were devided randomly into the GuRH and control group consisting of five hens each. The GnRH group was injected intramuscular into the pectoral muscle with 1 mL of 50pg/mI. GnRH, while the control group was injected with 1 mL of 0,9% saline for seven conseccutive days. The results showed significant (P<0,05) elevated producth;ty in the laying period (12 months) of the GnRB group from 50,601:0,75 eggs to 67,71:1:0,15 eggs as compared to that of the control group from 64,92x1,00 eggs to 40,521:0,30 eggs. GnRH injection, improved the egg laying cycle patterns as compared to the normal egg laying cycle by decreasing the lag time in a laying period (12 months) from 98,33:1:0,39 days to 68,00:0,81 days significantly (P<0,05) while the control group from 84,40:0,33 days to 71,33:0,78 days. Serom Progesterone concentration of the GnRH group (7,63; 1,93; 3,57; 2,92 ng/mL) increased and reached its peak significantly as compared to the control group (0,15; 0,01; 0,74; 0,98 ng/mL) on day 1, 2, 5 and 7 of treatment. The number of growing follicles (the number of F4, F5 follicles; F1, F2, F3 follicles weight) also increased significantly (P<0,05) in the GnRH group as compared to the control group, concomitant with the increasing ovarian and oviduct weight (p<0,05) in the GnRH group (37, 65:1, l6; 50,43:,58 g) aS compared to the control group (28,50:1,00; 31,15:1,65 g). GnRH also increased significanly (P< 0,05) the biometry of the reproductive organs. From this research it could be concluded that responsiveness of GnRH injection could increased Progesterone concentrations, resulting ill the number of follicular growth F4, F5 and ultimately Fl, F2, F3 increased egg production and repaired egg laying cycle. GnRH also increased weight of the ovaries, oviduct alld hiomelfy of the reproductive organs.
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Judul: Mapping of Coastline Changes in the Coastal of Bantul Regency Using Sentinel-2A Satellite Imagery
Abstrak: Pesisir merupakan wilayah yang kompleks akibat interaksi darat dan laut sehingga mudah mengalami perubahan secara fisik seperti perubahan garis pantai. Perubahan garis pantai penting diketahui untuk kajian pengelolaan kawasan pesisir, pemodelan pesisir, studi akresi-abrasi, serta analisis wilayah bahaya. Penelitian bertujuan memetakan dan menghitung laju perubahan garis pantai di Kabupaten Bantul, Daerah Istimewa Yogyakarta menggunakan citra Sentinel-2A pada tahun 2017, 2018 dan 2021. Metode digital shoreline analysis system (DSAS) digunakan untuk menghitung perubahan garis pantai secara statistik maupun geospasial. Lokasi penelitian terbagi menjadi 15 sub-zona dimana abrasi tertinggi terjadi pada Desa Parangtritis bagian timur (Sub-zona E3) dengan laju perubahan garis pantai mencapai -10,03 m/tahun. Abrasi dipengaruhi landainya kondisi pantai, gelombang dengan tinggi mencapai 2,39 m dan arus dengan kecepatan mencapai 0,24 m/s yang menggerus garis pantai serta tidak adanya penghalang di kawasan pantai. Akresi tertinggi terjadi di Desa Parangtritis bagian barat (Sub-zona E1) dengan laju perubahan garis pantai mencapai 9,20 m/tahun. Akresi dipengaruhi material sedimen dari darat yang mengendap dan menambah area garis pantai serta bergeraknya pasir oleh angin di sekitar gumuk pasir., Coastal is a complex area due to land and sea interactions so that it is easy to experience physical changes such as changes in coastlines. Coastline changes are important to know for coastal area management studies, coastal modeling, accretion-abrasion studies, and hazard area analysis. The study aimed to map and calculate the rate of change in coastlines in Bantul Regency, Yogyakarta Special Region using Sentinel-2A imagery on 2017, 2018 and 2021. The digital shoreline analysis system (DSAS) method used to calculate shoreline changes statistically and geospatially. The research location divided into 15 sub-zones where the highest abrasion occured in east Parangtritis Village (E3 sub-zone) with a coastline change rate of -10,03 m/year. Abrasion influenced by gentle coastal conditions, waves with a height of 2.39 m and currents with a speed of 0.24 m/s which erodes the coastline and there is no barrier in the coastal area. The highest accretion occurred in west Parangtritis Village (E1 sub-zone) with a coastline change 9,20 m/year. Accretion influenced by sedimentary material from land that settled and added to the coastline area and the movement of sand by the wind around the sand dune.
Keyword: abrasi, akresi, DSAS, Kabupaten Bantul, abrasion, accretion, Bantul Regency