Judul: Analysis of Climate and Population Dynamics of White Stem Borer Scirpopagha innotata (Walker) in Sumbawa Regency
Abstrak: Preliminary selection is conducted in order to choose which pest that will be presented in this research. Four consecutive years from 2009 to 2012 is selected as time range to measure rice harvest losses due to infectious pest outbreak. The white stem borer (Scirpophaga innotata) has been one of major pests that cause farmer worries over years in Sumbawa Regency. The climate dynamics as hypothesized one of important factors to drive pest development is the underlying to be concerned. Australia CSIRO’s DYMEX agroclimatic software is employed in constructing a pest dynamics model provided with biological cycle (egg, larva, pupa and adult) with approach using quantitative climate parameter. Therefore, the output will be subject for analysis of white stem borer dynamic population in the regency from 2009 to September 2012. The result shows that fluctuating involved climate parameters give influence on white stem borer development at every stage. Meanwhile heat and cold stress, humid stress, and washing, simultaneously act as limiting factor for each life stage development. Larva stage as deemed the most perilous stage causing rice plant damage, lives within considerably suitable range of temperature (23.8ºC – 31.6ºC), relative humidity (65% - 77%), rainfall (0 mm – 30 mm), thus Sumbawa climate circumstance comforts the pest development. Meanwhile, most intensifying larva infestation occurs on February 2010, September 2011, and September 2012 respectively.
Keyword: Bogor Agricultural University (IPB), Sumbawa Regency, climate dynamics, DYMEX, Scirpophaga innonata

Judul: Pemodelan Fenologi Populasi Penggerek Batang Padi Kuning Scirpophaga incertulas (Walker) Berbasis Pengaruh Iklim
Abstrak: West Java province is the highest of rice production area in Indonesia, contributing an average of national rice production about 17.4% in 2009 to 2012. Rice production can be maintained or enhanced if we have a great capability to protect rice from pests’ infestation. In 1995, the population of rice white stem borer (WSB) Scirpophaga innotata (Walker) decreased, while the population of the rice yellow stem borer (YSB) Scirpophaga incertulas (Walker) increased to 30%. Since 1995, YSB was more dominant than WSB, with population of more than 90%. Based on the report from Directorate of Food Crop Protection, some areas in the West Java in particular of North Coastal region has a total area of high annual infestation compared to other regions, reaching ± 10 to 12 thousand ha. High infestation of YSB is suspected as a result from transition of rice varieties. Furthermore, climatic might have strong influence on population dynamics of rice stem borer. Understanding relationship between climatic factors and life cycle and population dynamics of YSB is important for long- and short term management strategies, as control measures to reduce production and economic losses. This research utilized DYMEX software and aims to develop a population dynamic model of YSB and to assess model's ability to predict abundance and population peak of YSB under climate change scenario SRES A1FI and B1. Modeling the YSB requires two major components: climate parameter and lower developmental threshold temperatures (To) to describe life cycle of YSB from the egg, larva, pupa, and adult stages. DYMEX also describe development, mortality, transfer of individuals from one to the next life stages, fecundity and reproduction of YSB. The coefficient of determination (R2) of calibration models between predictions and observations showed a strong positive correlation of 0.72. Model validation could well predict the peak population, with R2 of 0.42. The simulations showed that the trend of population peaks occur at high rainfall i.e. in March to April, July to September, and November to December. The model predicted YSB population in the Sukamandi and Pusaka Negara reaches 3 generations per year, while in Kuningan 2 generations per year. Decrease in the population will affect the number generations of YSB in the three regions. Simulation models under climate change scenarios SRES A1FI and B1 showed differences in the sensitivities. Trend of YSB population is increasing in the regions Pusaka Negara and Kuningan and decreasing in region Sukamandi. Under changing climate, environment conditions in Pusaka Negara and Kuningan become more suitable for the proliferation YSB, allowing an increase in the number of generations per year. The level of model accuracy can still be improved by exploring more variables to include interactions between YSB and host plant (paddy) and the natural predators parasitism against the YSB. This makes model becomes more complex but may reflect better condition of YSB populations in the field. Further model improvement could be facilitated by be integrating DYMEX and CLIMEX software to determine the distribution of species in relation to climatic conditions. This models integration can simulate regional risks and determine whether a site could potentially be
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Judul: Ti-6Al-4V Terlapis Hidroksiapatit-Gelatin menggunakan Metode Dip-Coating Termodifikasi sebagai Implan Tulang
Abstrak: Titanium dan paduannya telah digunakan secara luas sebagai implan tulang. Akan tetapi, logam memiliki sifat adhesi yang buruk dan ketahanan korosi yang rendah sehingga diperlukan suatu pelapisan dengan material biokompatibel seperti hidroksiapatit (HAp). HAp yang akan dilapiskan pada logam harus memiliki ukuran pori yang kecil sehingga perlu dikompositkan dengan gelatin terlebih dahulu untuk menurunkan ukuran porinya. Oleh karena itu, tujuan dari penelitian ini adalah melapiskan HAp-gelatin pada paduan logam Ti-6Al-4V menggunakan metode dip-coating termodifikasi dan mencirikannya. Komposit HAp-gelatin 30% yang disintesis dengan metode in-situ dapat disalutkan pada paduan logam Ti-6Al-4V dengan metode dip-coating termodifikasi, yaitu dengan perendaman selama satu pekan. Sebelum dilapiskan logam Ti-6Al-4V dipotong menjadi kepingan bulat berdiameter 1.3 cm dengan tebal 3 mm. Kemudian logam dihaluskan, dicuci dengan etanol lalu akuades. Setelah itu, logam direndam dalam larutan NaOH yang diikuti dengan pembilasan dengan akuades. Implan Ti-6Al-4V-HAp-gelatin yang dihasilkan memiliki sifat ketahanan korosi yang lebih baik daripada logam Ti-6Al-4V yang tidak dilapis karena laju korosinya menurun dari 0.4152 mpy menjadi 0.2369 mpy. Ti-6Al-4VHAp- gelatin memiliki kekuatan mekanik yang baik karena hanya mengalami penurunan kekerasan sebesar 0.67% setelah dilapis. Implan juga dapat merangsang mineralisasi pada tulang melalui pelepasan ion Ca2+ dan terjadi pengendapan terlihat dari penurunan konsentrasi ion terlarutnya hingga 98.65%. Namun, Ti-6Al-4V-HAp-gelatin bersifat toksik di dalam sel endotel pada pengujian secara in-vitro. Hal ini disebabkan terlepasnya lapisan komposit HApgelatin yang menyebabkan sel endotel tertindih dan mengakibatkan kematian sel hingga 94.87%. Hasil analisis pola difraksi sinar-X pada Ti-6Al-4V-HAp-gelatin menunjukkan fase HAp dan Ti. Analisis spektrum inframerah menunjukkan keberadaan gugus fungsi hidroksil dan fosfat yang berasal dari HAp, karbonil dari gelatin, dan gugus karbonat yang berasal dari CaCO3 yang masih tersisa dalam sampel. Pemindaian elektron memperlihatkan morfologi Ti-6Al-4V-HAp-gelatin berbentuk granula-granula dan ukurannya beragam karena fasenya yang amorf. Sebagai saran, perlu diuji lebih lanjut metode pelapisan HAp-gelatin pada logam Ti-6Al-4V yang dapat menghasilkan penempelan yang lebih baik.
Keyword: dip-coating, gelatin, hidroksiapatit, implan, Ti-6Al-4V