Hasil Pencarian  ::  Simpan CSV :: Kembali

"A study at several geothermal systems in West Java,Indonesia shows that thermal waters could naturally contain up to 2.6 ppm As and 6.5 ppb Hg,and the survace hydrothermal alteration could contribute up to 50 ppm As and 800 ppb Hg...."

"This book is a comprehensive and authoritative study of the increasing need for commercial astronauts. Erik Seedhouse provides unique insights into the burgeoning new field of commercial space operation and the individuals who will run these missions. Section I begins by describing how Astronauts for Hire (A4H) was created in 2010 by Brian Shiro, a highly qualified NASA astronaut candidate, and a group of other astronaut candidates. Erik introduces A4H's vision for opening the space frontier to commercial astronauts and describes the tantalizing science opportunities offered when suborbital and orbital trips become routine. Section II describes the vehicles astronauts will use. Anticipation is on the rise for the new crop of commercial suborbital and orbital spaceships that will serve the scientific and educational market. These reusable rocket-propelled vehicles are expected to offer quick, routine, and affordable access to the edge of space, along with the capability to carry research and educational crew members. The quick turnaround of these vehicles is central to realizing the profit-making potential of repeated sojourns by astronauts to suborbital and orbital heights. Section III describes the various types of missions this new corps of astronauts will fly and who will hire them. For example, suborbital flights may be used to do high altitude astronomy, life science experiments, and microgravity physics. This section continues with an examination of the types of missions that will accelerate human expansion outward, to Exploration Class missions through lunar bases, the establishment of interplanetary spaceports, and outposts on the surface of Mars. Along the way it describes the tasks commercial astronauts will perform, ranging from mining asteroids to harvesting helium."

"EFFECTS OF CONCENTRATION, AND BODY SIZE ON THE BIOACCUMULATION OF MERCURY ON THE ARK COCKLES ANADARA ANTIQUATA. The kinetics of mercury bioaccumulation on the ark cockles Anadara antiquata were investigated by using radiotracer. An aquaria experiments applied to two groups of cockles, that were smaller (10-20mm) and bigger cockles (35-45 mm), three individuals each, with two replications. Four Hg2+ concentration (0.0025; 0.005; 0.01; and 0.02 μg.L-1) with 0.5 Bq.L-1 of 203Hg2+ were treated to both groups. The experiments of bioaccumulation lasted for 14 days, continued with 5 days depuration treatments. The observed variables were Bioconcentration Factor (BCF), uptake rates, efflux rates, contents of mercury in the body, and elimination rates of mercury. The models to predict BCF and elimination rates also had made. The results showed that Hg2+ bioaccumulation on smaller cockles was higher than bigger cockles. The increased of Hg2+ concentration in the water decreased the BCF on both groups. By the steady state of exposure period, the Bioconcentration Factor (BCF) of Hg was 775,532 on smaller cockles, and 378,708 on bigger cockles. The increased of Hg2+ concentration in the medium effected the increased ofHg2+ efflux rates, and Hg2+ contents in the body on both groups, but decreased the uptake rates on bigger cockles. There were no significant differences of Hg2+ retention percentage during depuration time on both groups."

"ABSTRAKKegiatan pertambangan emas skala kecil berdampak negatif pada aspek ekologi, sosial, dan ekonomi. Meski sudah dilakukan sosialisasi untuk menghentikan kegiatan tersebut, kegiatan penambangan emas skala kecil masih berlangsung. Penelitian bertujuan untuk: 1) menganalisis hubungan sikap, norma subyektif, dan persepsi tentang kemampuan mengubah perilaku dengan intensi untuk mengubah perilaku penambangan emas skala kecil, 2) menganalisis hubungan antara kebergantungan pada sumber daya tambang dan persepsi tentang kemampuan mengubah perilaku, dan 3) merancang strategi komunikasi untuk sosialisasi bahaya merkuri. Data dikumpulkan melalui wawancara terstruktur dan wawancara mendalam. Hasil uji korelasi rank Spearman menunjukkan bahwa sikap dan norma subyektif berhubungan negatif dengan intensi untuk mengubah perilaku. Sebaliknya, persepsi tentang kemampuan mengubah perilaku berhubungan positif dengan intensi untuk mengubah perilaku. Hanya sikap yang berhubungan nyata dengan intensi untuk mengubah perilaku. Tingkat kebergantungan pada sumber daya tambang berhubungan positif dengan persepsi tentang kemampuan mengubah perilaku. Strategi sosialisasi bahaya merkuri mencakup: 1) melibatkan berbagai pemangku kepentingan (pemerintah, tokoh masyarakat, perusahaan, akademisi) sebagai sumber pesan 2) menyampaikan pesan tentang sumber pencemaran, jalur pajanan, toksisitas merkuri serta valuasi ekonomi penggunaan merkuri, dan alternatif mata pencaharian lain, 3) memanfaatkan forum, media tercetak, dan media hibrida untuk penyampaian pesan, dan 4) melibatkan semua kalangan masyarakat sebagai penerima pesan

---

ABSTRACTSmall-scale gold mining give a negative impact in the aspect of ecology, social, and economy. Although some socialization aims to stop the activities had been employed, small scale mining activities still exist. Aims of the research: 1) analyzing the relation between attitude, subjective norm, and perceived ability to change behavior with the intention to change the behavior of the small-scale gold mining, 2) analyzing the relation between mine dependence with perceived ability to change behavior, 3) designing communication strategy in socializing mercury hazard. The data are collected by doing the structured and in-depth interview. The result of rank Spearman correlation test showed that attitude and subjective norm related nagatively with the intention to change behavior. On the contrary, perceived ability to change behavior related positively with the intention. Attitude is the only aspect that have signifficant relation with the intention to change behavior. The mine dependence related with the perceived ability to change behavior. The strategies of mercury hazard socialization: 1) involving the stakeholder (e.g. government, local public figure, the mining company, and academician) as sources of messages, 2) informing the source of pollution, exposure, mercury toxicity and economic valuation of mercury usage, and the living source alternative, 3) using forum, printed media, hybrid media in socializing, and 4) involving the community as the receiver.;"

"Pengaruh menghirup merkuri pada sel otak and efek ektrak teh hijau sebagai antioksidan. Merkuri dikenal sebagai metal yang toksik, dapat membentuk radikal bebas yang merangsang terjadinya stres oksidatif yang menyebabkan berbagai kelainan seperti kelainan otak. Tujuan: Penelitian ini bertujuan untuk mengindentifikasi pengaruh dari menghirup merkuri terhadap sel otak serta pengaruh ekstrak teh hijau (Camellia sinensis) sebagai antioksidan terhadap sel otak yang terpapar merkuri. Metode: Sampel penelitian ini adalah 48 Mus musculus jantanyang dibagi menjadi 8 grup yang diberi perlakuan selama 3 dan 6 minggu. Grup A merupakan kontrol negatif tanpa perlakuan. Grup B merupakan kontrol positif yang diberi perlakuan dengan merkuri. Grup C diberikan perlakuan dengan merkuri dan 26µg/g ekstrak teh hijau. Grup D diberi perlakuan merkuri dan 52µg/g ekstrak teh hijau. Seluruh mencit pada grup B, C, dan D diberikan perlakuan merkuri secara inhalasi selama 4 jam/hari. Selanjutnya dilakukan pemeriksaan histopatologi untuk mengevaluasi efek merkuri serta efek antioksidan dari ekstrak teh hijau. Hasil: Jumlah sel otak yang nekrotik lebih sedikit pada kelompok yang diberikan ekstrak teh hijau dibandingkan dengan kelompok yang tidak menerima ekstrak teh hijau. Perbedaan ini bermakna secara statistik (p<0,05). Simpulan: Menghirup merkuri menyebabkan nekrosis sel otak. Pemberian ekstrak teh hijau menurunkan jumlah sel nekrotik pada mencit yang telah terpapar merkuri.

---

Mercury is a wellknown toxic metal that is capable to induce free radical-induced oxidative stress. It can cause human disease including brain disorders. Objective: To identify the effect of mercury vapor inhalation on brain cells and the role of green tea extract (Camellia sinensis) as antioxidant on the brain cells exposed to mercury. Methods: Fourty-eight male Mus musculus were divided into 8 groups, which were given treatment for 3 and 6 weeks. Group A did not receive any treatment and served as a negative control. Group B was a positive control exposed to Mercury. Group C was exposed to Mercury and treated with 26µg/g green tea extract. Group D was exposed to mercury and treated with 52µg/g green tea extract. All animals in the Group B, C, D were exposed to mercury through inhalation for 4 hours daily. The effect of mercury on the brain cells were examined histopathologically. Results: The numbers of necrotic cells counted in the green tea-treated mice group were significantly lower than those untreated group (p<0,05). Conclusion: Mercury vapor inhalation may cause necrosis on brain cells. Administration of green tea extract as an antioxidant reduced the amount of mercury-induced necrotic brain cells in mice."

"Delesi GSTT1 dan GSTM1 mempengaruhi detoksifikasi xenobiotik seperti merkuri dari dalam tubuh. Amalgam merupakan salah satu sumber paparan merkuri pada tubuh manusia.Tujuan : mengetahui pola distribusi sebaran genotip delesi GSTT1 dan GSTM1 pada populasi Indonesia, menganalisis perbedaan kadar merkuri dalam urin antara subjek dengan dan tanpa amalgam serta keterkaitan antara delesi gen dengan merkuri dari amalgam serta jeniskelamin.Metode : Cross-sectional, 264 ekstrak DNA, 50 sampel urin sebagai subjek penelitian.Hasil dan Kesimpulan : Frekuensi delesi GSTT1 lebih besar dibandingkan GSTM1 pada populasi Indonesia. Tidak terdapat hubungan antara delesi gen dengan kadar merkuri serta jenis kelamin.

---

Background : GSTT1 and GSTM1 deletion affected xenobiotic detoxification such as mercury from inside the body. Amalgam is one source of mercury exposure on the human body.

Aim : To describe the distribution pattern of of GSTT1 and GSTM1 deletion on the Indonesian population, analyze the differences in urinary mercury levels between subjects with and without amalgam and also the relationship between gene deletions with amalgam?s mercury and gender.

Methods : Cross-sectional study. 264 DNA extracts, 50 urine samples as a research subjects.

Results and Summary : The GSTT1 deletion frequency is bigger than GSTM1 on the Indonesian population. There was no correlation between gene deletions with mercury levels and gender."