545 research outputs found
Pemanfaatan Tumbuhan Secara Tradisional Di Taman Nasional Gunung Halimun*[traditional Plant Use in Gunung Halimun National Park]
Gunung Halimun National Park (GHNP) is one of the remaining tropical forest in Java, still has high interaction with people who live in the surrounding areas.Eventhough there were some studies on ecology and ethnobotany in this area,it is still lacking of information on these subjects.This paper presented the results of ethno-ecology studies at several areas in GHNP such as East Halimun sector (around Gn.kendeng) and South Halimun sector (around Pangguyangan). The studies were carried out through vegetation analysis with Random Quadrats method and Participation method with interview technique.By these methods data were collected for the Important Value Index (IVI) and the Use Value Index (UVI) of species.These values showed that rasamala (Altingia excelsa), for tree stage, has the highest IVI and UVI but for the sapling stage the IVI is low. Kianak (Castanopsis acuminatissima) for tree and sapling stages the IVI is high but the UVI is low, while for maja (Magnolia macklottii), the UVI is high but the IVI is low for both tree and sapling stages. Based on these data, analyzed was done regarding the presence and the prospect of these species, in the context of the lifestyle of the villagers
An Assessment of Vegetation Variables in the Reclamation Area of the Ex-gold Mining at Ratatotok, Southeast Minahasa
The reclamation area of the ex gold-mining PT. Newmont Minahasa Raya (PT. NMR) will be used as a botanic gardens. This study aims to assess the reclamation program\u27s success based on a variable vegetation of the ex gold-mining area of PT. NMR for the basis of the next management. Observations of vegetation on each unit of area was done by nested sampling system, where plots were placed along a perpendicular transect in a contour line. Vegetation variables were recorded among other: species name, individual number, plot numbers, coordinates, temperature, humidity, canopy cover, and land cover. The effect of vegetation on both of two variable regions, revegetation area and non-revegetation area, was tested using discriminant analysis. The results showed that the vegetation composition of the ex gold mining area of PT. NMR was still dominated by introduction species i.e. gamal (Gliricidia sepium), mahoni (Swietenia macrophylla), and lamtoro (Leucaena leucocephala). The diversity of understorey vegetation was middle category. The vegetation structure of the revegetation area was still in its infancy and has not yet reached climax conditions. However, revegetation efforts PT. NMR has succeeded in restoring the composition and structure of vegetation resembling to vegetation conditions in secondary forests. For supporting the ecosystem stability and promoting development programs of botanic gardens, were the enrichment of native vegetation and endangered species is needed
Desain Vegetasi Bernilai Konservasi Dan Ekonomi Pada Kawasan Penyangga Sistem Tata Air DAS Bolango (Designing of Vegetation Which Conservation and Economic Values in the Buffer Area of Water System at the Bolango Watershed)
Perencanaan pembangunan arboretum di DAS Bolango dengan konsep konservasi dan ekonomi perlu dilakukan karena DAS ini memiliki peranan yang penting dalam kehidupan masyarakat sekitar. Tujuan penelitian ini adalah memberikan rekomendasi tentang komposisi dan struktur vegetasi penyusun hutan pada kawasan arboretum sebagai pemelihara mata air Sungai Bolango. Penelitian dimulai dengan mengidentifikasi sumber mata air, tanah, dan kondisi vegetasi eksisting. Metode wawancara kepada masyarakat setempat dilakukan untuk mendukung data etnobotani. Kajian lahan dilakukan antara lain tata guna, kelas kemampuan, konsep pengelolaan, kesesuaian lahan, dan penentuan vegetasinya. Hasil identifikasi sumber mata air menunjukkan bahwa terdapat 3 lokasi yang potensial dibangun arboretum, yaitu Desa Meranti Kecamatan Tapa Kabupaten Bone Bolango, Desa Dulamayo Selatan Kecamatan Telaga Kabupaten Gorontalo, dan Desa Mongiilo Kecamatan Bolango Ulu Kabupaten Bone Bolango. Berdasarkan data kualitas tanah, ketiga lokasi memiliki media perakaran yang cukup baik untuk tanaman budi daya. Secara umum, semua jenis tanaman budi daya sesuai untuk ditanam di ketiga lokasi arboretum. Perlu dilakukan pembuatan teras dan penerapan pola tanam konservasi yang mengaplikasikan tanaman penutup tanah (cover crop), tanaman budi daya, dan pohon penyusun hutan. Selain itu, perlu pemberian pupuk organik berupa kompos dan pupuk kandang
Observation of Multi-Tev Gamma Rays from the Crab Nebula Using the Tibet Air Shower Array
The Tibet experiment, operating at Yangbajing (4,300 m above sea level), is
the lowest energy air shower array and the new high density array constructed
in 1996 has sensitivity to -ray air showers at energies as low as 3
TeV. With this new array, the Crab Nebula was observed in multi-TeV
-rays and a signal was detected at the 5.5 level. We also
obtained the energy spectrum of -rays in the energy region above 3 TeV
which partially overlaps those observed with imaging atmospheric Cherenkov
telescopes. This is the first observation of -ray signals from point
sources with a conventional air shower array using scintillation detectors.Comment: 9 pages, 4 figures, Accepted for publication in ApJ Letter
Observation of Multi-Tev Diffuse Gamma Rays from the Galactic Plane with the Tibet Air Shower Array
Data from the Tibet-III air shower array (with energies around 3 TeV) and
from the Tibet-II array (with energies around 10 TeV) have been searched for
diffuse gamma rays from the Galactic plane. These arrays have an angular
resolution of about 0.9 degrees. The sky regions searched are the inner Galaxy,
20 degrees <= l <= 55 degrees, and outer Galaxy, 140 degrees <= l <= 225
degrees, and |b| <= 2 degrees or <= 5 degrees. No significant Galactic plane
gamma-ray excess was observed. The 99% confidence level upper limits for
gamma-ray intensity obtained are (for |b| <= 2 degrees) 1.1 times 10^{-15}
cm^{-2}s^{-1}sr^{-1}MeV^{-1} at 3 TeV and 4.1 times 10^{-17}
cm^{-2}s^{-1}sr^{-1}MeV^{-1} at 10 TeV for the inner Galaxy, and 3.6 times
10^{-16} cm^{-2}s^{-1}sr^{-1}MeV^{-1} at 3 TeV and 1.3 times 10^{-17}
cm^{-2}s^{-1}sr^{-1}MeV^{-1} at 10 TeV for the outer Galaxy, assuming a
differential spectral index of 2.4. The upper limits are significant in the
multi-TeV region when compared to those from Cherenkov telescopes in the lower
energy region and other air shower arrays in the higher energy region; however,
the results are not sufficient to rule out the inverse Compton model with a
source electron spectral index of 2.0.Comment: 22 pages, 8 figures, Accepted for publication in Ap
Easi-CRISPR: a robust method for one-step generation of mice carrying conditional and insertion alleles using long ssDNA donors and CRISPR ribonucleoproteins
Background
Conditional knockout mice and transgenic mice expressing recombinases, reporters, and inducible transcriptional activators are key for many genetic studies and comprise over 90% of mouse models created. Conditional knockout mice are generated using labor-intensive methods of homologous recombination in embryonic stem cells and are available for only ~25% of all mouse genes. Transgenic mice generated by random genomic insertion approaches pose problems of unreliable expression, and thus there is a need for targeted-insertion models. Although CRISPR-based strategies were reported to create conditional and targeted-insertion alleles via one-step delivery of targeting components directly to zygotes, these strategies are quite inefficient.
Results
Here we describe Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR), a targeting strategy in which long single-stranded DNA donors are injected with pre-assembled crRNA + tracrRNA + Cas9 ribonucleoprotein (ctRNP) complexes into mouse zygotes. We show for over a dozen loci that Easi-CRISPR generates correctly targeted conditional and insertion alleles in 8.5–100% of the resulting live offspring.
Conclusions
Easi-CRISPR solves the major problem of animal genome engineering, namely the inefficiency of targeted DNA cassette insertion. The approach is robust, succeeding for all tested loci. It is versatile, generating both conditional and targeted insertion alleles. Finally, it is highly efficient, as treating an average of only 50 zygotes is sufficient to produce a correctly targeted allele in up to 100% of live offspring. Thus, Easi-CRISPR offers a comprehensive means of building large-scale Cre-LoxP animal resources
Detection of Multi-TeV Gamma Rays from Markarian 501 during an Unforeseen Flaring State in 1997 with the Tibet Air Shower Array
In 1997, the BL Lac Object Mrk 501 entered a very active phase and was the
brightest source in the sky at TeV energies, showing strong and frequent
flaring. Using the data obtained with a high density air shower array that has
been operating successfully at Yangbajing in Tibet since 1996, we searched for
gamma-ray signals from this source during the period from February through
August in 1997. Our observation detected multi-TeV -ray signals at the
3.7-Sigma level during this period. The most rapid increase of the excess
counts was observed between April 7 and June 16 and the statistical
significance of the excess counts in this period was 4.7-Sigma. Among several
observations of flaring TeV gamma-rays from Mrk 501 in 1997, this is the only
observation using a conventional air shower array. We present the energy
spectrum of gamma-rays which will be worthy to compare with those obtained by
imaging atmospheric Cerenkov telescopes.Comment: 9 pages, 7 figures, To appear in Ap
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