40Ar/39Ar ages from blueschists of the Jambaló region, Central Cordillera of Colombia : implications on the styles of accretion in the Northern Andes

This paper presents the first argon dating of blueschists from the Jambaló area (Cauca Department) in the Central Cordillera of the Colombian Andes. Step-heating 40Ar/39Ar spectra were obtained for mica from several lenses of blueschists including greenschist facies rocks. The blueschists are mainly constituted of preserved lenticular cores in strongly mylonitic rocks, which resulted from retrometamorphic processes that affected the high pressure rocks during their exhumation. The majority of 40Ar/39Ar data points to metamorphic ages close to 63±3Ma, but some ages are older than 71Ma. These Maastritchtian-Danian ages correspond to the timing of exhumation of the blueschists near metamorphic peak conditions, because the dated paragonite and phengite crystallized during development of the mylonitic foliation. The continuous exhumation of this blueschist belt between 71-63Ma reflects the flow on an accretionary system/subduction channel environment that was interrupted by the collision of an intra-oceanic arc with the continental margin. Regional geological correlations suggest that this arc-continent collision also took place in Ecuador. This collisional event, although synchronous with other arc-continent collisions in the Northern Andes, was apparently not related to the formation of the great Caribbean arc, but to an arc built in the southeastern margin of the Caribbean plate

Pengaruh Penambahan Kosubstrat Pada Biodegradasi Crude Oil

Kegiatan penambangan minyak bumi tidak hanya dilakukan oleh Perusahaan-Perusahaan besar, tetapi juga oleh masyarakat secara tradisional. Potensi pencemaran lingkungan yang ditimbulkan oleh kegiatan penambangan rakyat ini menjadi lebih tinggi karena pengelolaannya yang tradisional. Salah satu jenis pencemaran yang ditimbulkannya misalnya adalah tanah atau perairan yang tercemar oleh minyak bumi (crude oil) pada saat berlangsungnya kegiatan penambangan. Salah satu upaya untuk dapat mengatasinya adalah dengan bioremediasi. Bioremediasi merupakan teknologi pengolahan pencemar dengan memanfaatkan aktivitas mikroba, terutama dari golongan bakteri. Bioremediasi tersebut harus melibatkan bakteri yang memiliki kapasitas metabolic untuk melakukan biodegradasi terhadap crude oil tersebut. Crude oil sendiri pada dasarnya merupakan senyawa hidrokarbon yang merupakan sumber karbon yang kaya bagi mikroba. Namun demikian, biodegradasi crude oil relative lebih sulit dilakukan karena karakteristiknya yang merupakan senyawa dengan berat molekul dan ukuran yang besar. Oleh karena itu penambahan kosubstrat yang lebih sederhana dapat dilakukan untuk membantu biodegradasi terutama pada tahap awal proses. Penelitian ini dilakukan untuk mengetahui pengaruh penambahan kosubstrat dalam hal ini glukosa terhadap biodegradasi crude oil. Penelitian dilakukan dalam media cair dengan bioaugmentasi melalui penambahan inoculum bakteri yang diisolasi dari tanah yang dikondisikan terhadap crude oil dalam beberapa variasi reactor. Indikasi terjadinya biodegradasi diperiksa melalui pengukuran terhadap parameter Total Petroleum Hydrocarbon (TPH) dan Total Plate Count (TPC). Hasil penelitian menunjukkan bahwa penambahan kosubstrat glukosa memberikan pengaruh positif terhadap penurunan TPH. Penurunan TPH tertinggi setelah 28 hari adalah sebesar 25,3 % yang diberikan oleh reactor dengan penambahan kosubstrat serta konsentrasi crude oil awal sebesar 8.1 %. Sementara itu reactor tanpa penambahan penambahan glukosa, penurunan TPH-nya hanya mencapai 19,4 %

On the link between conscious function and general intelligence in humans and machines

In popular media, there is often a connection drawn between the advent of awareness in artificial agents and those same agents simultaneously achieving human or superhuman level intelligence. In this work, we explore the validity and potential application of this seemingly intuitive link between consciousness and intelligence. We do so by examining the cognitive abilities associated with three contemporary theories of conscious function: Global Workspace Theory (GWT), Information Generation Theory (IGT), and Attention Schema Theory (AST). We find that all three theories specifically relate conscious function to some aspect of domain-general intelligence in humans. With this insight, we turn to the field of Artificial Intelligence (AI) and find that, while still far from demonstrating general intelligence, many state-of-the-art deep learning methods have begun to incorporate key aspects of each of the three functional theories. Given this apparent trend, we use the motivating example of mental time travel in humans to propose ways in which insights from each of the three theories may be combined into a unified model. We believe that doing so can enable the development of artificial agents which are not only more generally intelligent but are also consistent with multiple current theories of conscious function

Future Water Management Problems in Asian Megacities

Today, about half of the world population lives in urban areas and in the coming 20 years, urbanization is expected to increase steadily, especially in the Developing World. Based on UN data and projections, about 4 out of the 5 billion world urban population will live in developing countries by 2030. Large cities in the Developing World face the problem of unplanned growth, coupled with the financial and operational inability to offer the public services needed to sustain a decent life in urban environments. Water is one of those essential commodities which is often short in supply and/or of low quality. Additionally, flood poses a threat to urban dwellers during rainy season. The water management challenges in tropical urban areas today and in the decades to come can be characterized by (1) fighting physical shortcomings in water resources, (2) coping with contamination of groundwater, rivers, lakes, and reservoirs by domestic, agricultural or industrial waste and waste water, (3) mitigating environmental impacts of water extraction (such as loss of wetlands, subsidence and seawater intrusion) , (4) preventing / mastering flood situations and (5) overcoming administrative and financial strains and operational incapacities. Solutions to the problems of urban water in 20 years time are to be found in supply side and demand side measures. The first group includes (1) optimal use of surface water and groundwater resources, (2) pollution protection, (3) watershed management and (4) more water storage. The second group includes (1) educational training, (2) technological innovation, (3) water conservation and (4) water pricing

Isolasi Dan Seleksi Bakteri Penghasil Biosurfaktan Yang Terdapat Di Dalam Deposit Lilin Pada Pipa Transmisi Minyak Mentah

Salah satu komponen berat di dalam minyak bumi yaitu parafin/wax akan mengendap pada dinding pipa transmisi apabila temperatur berkurang seiring minyak yang ditransmisikan mendekati permukaan bumi. Selain penanganan secara mekanis dan isolasi termal juga terdapat penangan dengan penambahan bahan kimia sejenis surfaktan untuk menurunkan tegangan permukaan kemudian membentuk mikroemulsi sehingga minyak dapat larut di dalam air begitu sebaliknya. Biosurfaktan menjadi alternatif menjanjikan yang ramah lingkungan, relatif mudah untuk dikembangkan dengan biaya yang relatif lebih murah. Tujuan dari penelitian ini yaitu menemukan isolat bakteri penghasil biosurfaktan menggunakan metode isolasi bakteri dari deposit lilin di dalam pipa transmisi minyak mentah kemudian diseleksi bakteri penghasil biosurfaktan. Didapatkan isolat bakteriEnterobacter gergoviaedanBurkholderia cepacia. Bakteri yang berkaitan dengan penghasil biosurfaktan disini yaitu bakteri Burkholderia cepacia yang memiliki waktu generasi 68,4 menit dengan konstanta laju pertumbuhan 0,61 per jam