Dinamika Perubahan Komposisi Gulma Pada Tanaman Tebu Keprasan Di Lahan Sistem Reynoso Dan Tegalan

Gulma adalah komponen yang tetap pada agroekosistem. Penelitian ini dilakukan un-tuk mempelajari Perubahan komposisi gul-ma pada tanaman tebu keprasan di lahan sistem reynoso dan tegalan. Penelitian ini dilaksanakan pada bulan Januari sampai Mei 2014 di Desa Legundi, Kecamatan Karang Jati, Kabupaten Ngawi. Hasil penelitian menunjukkan bahwa terdapat 35 spesies gulma yang ada di lahan sistem reynoso. Gulma yang mendominasi di lahan sistem reynoso adalah Chromolaena odorata (kirinyu), Ipomoea triloba (rayutan), Cayratia trifolia (galing-galing) dan Phyllanthus niruri (meniran). Gulma yang tersusun di lahan tegalan terdapat 33 spesies. Gulma yang mendominasi di lahan tegalan adalah Digitaria sanguinalis (jam-pang piit), Brachiaria distachya (gajihan) dan Ageratum conyzoides (wedusan). Nilai Indeks Shanon-Wienner berkisar antara 2,66-3,20 yang berarti tingkat keaneka-ragaman gulma pada lahan penelitian tergolong dalam kategori sedang. Nilai Indeks Simpson berkisar antara 0,05-0,13 yang berarti struktur komunitas dalam keadaan stabil dan tidak terjadi dominasi individu spesies gulma pada lahan penelitian. Nilai Indeks Sebaran Morisita (Id) pada lahan penelitian berkisar antara 0,00-12,28. Pola sebaran gulma di lahan sistem reynoso cenderung berkelompok dan merata, sedangkan di lahan tegalan gulma cenderung memiliki pola sebaran berkelompok

Microcrystalline silicon thin film transistors obtained by Hot-Wire CVD

Polysilicon thin film transistors (TFT) are of great interest in the field of large area microelectronics, especially because of their application as active elements in flat panel displays. Different deposition techniques are in tough competition with the objective to obtain device-quality polysilicon thin films at low temperature. In this paper we present the preliminary results obtained with the fabrication of TFT deposited by hot-wire chemical vapor deposition (HWCVD). Some results concerned with the structural characterization of the material and electrical performance of the device are presented

Validation of the log e–log σ normal compression law using particle strength data

This note is a study of experimental data on particle strength and normal compression, to establish whether the recently proposed normal compression law by McDowell and de Bono (2013) is supported and confirmed. A number of different sands are examined and found to support the hypothesis. In addition, some new simulations on sand mixtures are used to explain experimental results for quartz-feldspar mixtures. It would appear that the proposed compression law is also supported by the data for the sand mixtures

Thin Film Transistors obtained by Hot-Wire CVD

Hydrogenated microcrystalline silicon films obtained at low temperature (150-280°C) by hot wire chemical vapour deposition at two different process pressures were measured by Raman spectroscopy, X-ray diffraction (XRD) spectroscopy and photothermal deflection spectroscopy (PDS). A crystalline fraction >90% with a subgap optical absortion 10 cm -1 at 0.8 eV were obtained in films deposited at growth rates >0.8 nm/s. These films were incorporated in n-channel thin film transistors and their electrical properties were measured. The saturation mobility was 0.72 ± 0.05 cm 2/ V s and the threshold voltage around 0.2 eV. The dependence of their conductance activation energies on gate voltages were related to the properties of the material

A common copy-number variant within SIRPB1 correlates with human Out-of-Africa migration after genetic drift correction

Previous reports have proposed that personality may have played a role on human Out-Of- Africa migration, pinpointing some genetic variants that were positively selected in the migrating populations. In this work, we discuss the role of a common copy-number variant within the SIRPB1 gene, recently associated with impulsive behavior, in the human Out-Of-Africa migration. With the analysis of the variant distribution across forty-two different populations, we found that the SIRPB1 haplotype containing duplicated allele significantly correlated with human migratory distance, being one of the few examples of positively selected loci found across the human world colonization. Circular Chromosome Conformation Capture (4C-seq) experiments from the SIRPB1 promoter revealed important 3D modifications in the locus depending on the presence or absence of the duplication variant. In addition, a 3' enhancer showed neural activity in transgenic models, suggesting that the presence of the CNV may compromise the expression of SIRPB1 in the central nervous system, paving the way to construct a molecular explanation of the SIRPB1 variants role in human migration

Analysis of bias stress on thin-film transistors obtained by Hot-Wire Chemical Vapour Deposition

The stability under gate bias stress of unpassivated thin film transistors was studied by measuring the transfer and output characteristics at different temperatures. The active layer of these devices consisted of in nanocrystalline silicon deposited at 125 °C by Hot-Wire Chemical Vapour Deposition. The dependence of the subthreshold activation energy on gate bias for different gate bias stresses is quite different from the one reported for hydrogenated amorphous silicon. This behaviour has been related to trapped charge in the active layer of the thin film transistor

Shear behaviour of crushed concrete and bricks

Demolition waste materials mainly consist of concrete and bricks and arise from the demolition of existing structures and buildings. Environmental and economical reasons make their recycling necessary, but to date, their use is curtailed due to the lack of research in determining their properties. This paper reports on the efforts to understand the behavioural characteristics of three types of recycled material to determine their potential for engineering fill applications. For this purpose, their physical and mechanical characteristics were extensively investigated. Two types of crushed concrete, one obtained straight after demolition and the other processed to industry specifications, and one type of crushed brick were tested. An extensive large-scale shear box test regime was employed to determine the shear strength behaviour of the materials. The influence of the normal stress on the peak friction angle, the shear stress– horizontal displacement relationship and horizontal displacement– vertical displacement behaviour of the materials are discussed in this paper. The results showed that the behaviour of the three recycled materials during shear testing was similar to the behaviour exhibited by natural granular materials from literature. In conclusion, the shear box test results have shown that the specific demolition waste products exhibit considerable shear strength and can be utilised in construction as low-level engineering fill

The effects of applied water at various fractions of measured evapotranspiration on reproductive growth and water productivity of Thompson Seedless grapevines

The reproductive growth and water productivity (WPb) of Thompson Seedless grapevines were measured as a function of applied water amounts at various fractions of measured grapevine ETc for a total of eight irrigation treatments. Shoots were harvested numerous times during the growing season to calculate water productivity. Berry weight was maximized at the 0.6–0.8 applied water treatments across years. As applied water amounts increased soluble solids decreased. Berry weight measured at veraison and harvest was a linear function of the mean midday leaf water potential measured between anthesis and veraison and anthesis and harvest, respectively. As applied water amounts increased up to the 0.6–0.8 irrigation treatments there was a significant linear increase in yield. Yields at greater applied water amounts either leveled off or decreased. The reduction in yield on either side of the yearly maximum was due to fewer numbers of clusters per vine. Maximum yield occurred at an ETc ranging from 550 to 700 mm. Yield per unit applied water and WPb increased as applied water decreased. The results from this study demonstrated that Thompson Seedless grapevines can be deficit irrigated, increasing water use efficiency while maximizing yields

Oocyte expression with injection of purified T7 RNA polymerase.

International audienceThe Xenopus oocyte is a widely used system for protein expression. Investigators have had the choice between two different techniques: injection into the cytoplasm of in vitro transcribed complementary RNA (cRNA) or injection into the nucleus of complementary DNA (cDNA). We report on a third expression technique that is based on the combined injection of cDNA and purified T7 RNA polymerase directly into the cytoplasm of oocytes