46 research outputs found
Diurnal emissivity dynamics in bare versus biocrusted sand dunes
No full textLand surface emissivity (LSE) in the thermal infrared depends mainly on the ground cover and on changes in soil moisture. The LSE is a critical variable that affects the prediction accuracy of geophysical models requiring land surface temperature as an input, highlighting the need for an accurate derivation of LSE. The primary aim of this study was to test the hypothesis that diurnal changes in emissivity, as detected from space, are larger for
areas mostly covered by biocrusts (composed mainly of cyanobacteria) than for bare sand areas. The LSE dynamics were monitored from geostationary orbit by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) over a sand dune field in a coastal desert region extending across both sides of the Israel–Egypt political borderline.
Different land-use practices by the two countries have resulted in exposed, active sand dunes on the Egyptian side (Sinai), and dunes stabilized by biocrusts on the Israeli side (Negev). Since biocrusts adsorb more moisture
from the atmosphere than bare sand does, and LSE is affected by the soil moisture, diurnal fluctuations in LSE were larger for the crusted dunes in the 8.7 μm channel. This phenomenon is attributed to water vapor adsorption
by the sand/biocrust particles. The results indicate that LSE is sensitive to minor changes in soil water content caused by water vapor adsorption and can, therefore, serve as a tool for quantifying this effect, which has a
large spatial impact. As biocrusts cover vast regions in deserts worldwide, this discovery has repercussions for LSE estimations in deserts around the globe, and these LSE variations can potentially have considerable effects on geophysical models from local to regional scales
Mid-uv meteor spectroscopy
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Complete genome sequence of carbonic anhydrase producing psychrobacter sp. SHUES1
No full text© 2016 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence.
The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fmicb.2016.01442Recent advances in biotechnology have allowed the study of new bacterial strains, which can produce enzymes that can be used in the bioremediation of heavy metals. Microbially induced carbonate precipitation (MICP) is a recent well-recognized process that has the potential to precipitate heavy metals, mainly those with a valency of +2 (Kumari et al., 2016). There are two enzymes, urease, and carbonic anhydrase, that play an important role in the MICP process. The role of carbonic anydrase (EC 4.2.1.1) in MICP is generally underestimated and most of the studies in past mainly focus on urease-producing microorganisms (Li et al., 2013, 2014; Kumari et al., 2014). In the present study, Psychrobacter sp. SHUES1 was isolated from frozen alkaline soil sample collected at Shanghai, China. This bacterium produced lipase and protease at 4°C in a plate assay. The ability of Psychrobacter sp. to show extracellular lipolytic activity at low temperatures is widely known (Xuezheng et al., 2010); however, the remarkable property of this strain was in the precipitation of heavy metals including cadmium and zinc in parallel to the MICP process. Therefore, to know the type of enzyme or genes involved in the process of metal precipitation, this research aims to sequence the whole genome of Psychrobacter sp. SHUES1, and thus provide a genomic insight into its behavior. Genomic DNA from Psychrobacter sp. SHUES1 was extracted using the DNeasy Blood & Tissue Kit (Qiagen, USA), and its quantity and quality were evaluated on the Qubit. The extracted DNA was subjected to whole-genome shotgun sequencing using the NEBNext Ultra DNA Library Prep Kit (Illumina, San Diego, CA). Library construction was performed with the following process: DNA fragmentation, end repair, adding “A” to the 3′ end, adaptor ligation and amplification. After library construction, the generated cluster was sequenced on an Illumina HiSeq2500 sequencing system, according to a paired end 2 × 125 nt multiplex program. 13,716,515 raw reads resulted in 13,144,818 quality-filtered trimmed reads, yielding a not less than 3 Mb genome size. De novo genome assembly was performed using SPAdes-3.5.0. After purification, the assembly produced 3,115,590 bp of sequence across 115 contigs with an N50 of 47,049 bp, with a longest sequence of 182,144 bp, and a G+C content of 43.5% (Table 1). Gene prediction and annotation were carried out using Prodigal_v2.6.1, blastp in the National Center for Biotechnology Information (NCBI) “nr” database. Gene ontology (GO) functional annotation of genes was carried out using the blast2GO algorithm, dominated by the following features: biological process (44%), molecular process (42%), and cellular component (14%). Clusters of Orthologous Groups (COG) annotation was carried out in the NCBI COG database using rpsblast. A total of 2627 protein-coding genes, 45 tRNA-coding genes, and 6 rRNA genes were predicted in the draft genome. TABLE 1 www.frontiersin.org Table 1. Genome features of Psychrobacter sp. SHUES1. The most significant finding of the whole genome sequencing of Psychrobacter sp. SHUES1 was the presence of carbonic anhydrase gene in it. Carbonic anhydrase participates in all physiological processes dealing with CO2 and HCO3, such as cellular pH regulation, calcification, acid, and ion transport (Smith and Ferry, 2000; Achal and Pan, 2011). It catalyses the interconversion of CO2 and HCO3, which ultimately promotes the precipitation of calcium carbonate in the presence of Ca2+ ions. Although there are a number of genome sequences of Psychrobacter sp. deposited in NCBI database, this is the first characterization of the genome sequence of strain SHUES1, which produces carbonic anhydrase which has a significant role in metal bioremediation based on the ability to promote the precipitation of metal carbonates. This sequencing result also suggests the importance of carbonic anhydrase in the MICP process which is a novel element in this field of research. The present study is especially valuable in the area of biomineralization based on MICP processes, in the bioremediation of metals and in the development of microbial concrete (biocement). Urease is the main enzyme responsible in such studies; however, in our study the urease gene was not present in Pyschrobacter sp. SHUES1. This indicates the importance of carbonic anhydrase, as a less studied secondary enzyme for the MICP process. It is hoped that this research will encourage other researchers to look for this carbonic anhydrase precipitation pathway when carrying out MICP studies
Aqueous Two-Phase Extraction of Lipase from Rice Bran
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Effects of Low-Temperature Operation on the Performance of MOSFETs
No full textabstract: The existing compact models can reproduce the characteristics of MOSFETs in the temperature range of -40oC to 125oC. Some applications require circuits to operate over a wide temperature range consisting of temperatures below the specified range of existing compact models, requiring wide temperature range compact models for the design of such circuits. In order to develop wide temperature range compact models, fourteen different geometries of n-channel and p-channel MOSFETs manufactured in a 0.18μm mixed-signal process were electrically characterized over a temperature range of 40 K to 298 K. Electrical characterization included ID-VG and ID-VD under different drain, body and gate biases respectively. The effects of low-temperature operation on the performance of 0.18μm MOSFETs have been studied and discussed in terms of sub-threshold characteristics, threshold voltage, the effect of the body bias and linearity of the device. As it is well understood, the subthreshold slope, the threshold voltage, drive currents of the MOSFETs increase when the temperature of the MOSFETs is lowered, which makes it advantageous to operate the MOSFETs at low-temperatures. However the internal linearity gm1/gm3 of the MOSFETs degrades as the temperature of the MOSFETs is lowered, and the performance of the MOSFETs can be affected by the interface traps that exist in higher density close to conduction band and valence band energy levels, as the Fermi-level moves closer to bandgap edges when MOSFETs are operated at cryogenic temperatures.Dissertation/ThesisM.S. Electrical Engineering 201
Society and sustainable life position
No full textPráce se zabývá vztahem lidské společnosti k přírodě a zhoršujícím se stavem přírodního prostředí. Autor hledá možné příčiny v náboženských a obecně myšlenkových tradicích naší západní civilizace a zhoršujícím se stavem přírodního prostředí. V další části uvádí dvě možnosti řešení ekologické krize, první řešení je technokratické a druhé hlubinně ekologické, které spočívá v radikální změně dosavadního způsobu života lidstva, tedy v opuštění výrazně konzumního stylu života, decentralizaci společnosti vytvořením malých do značné míry soběstačných komunit.This bachelor thesis is enganged in human society's relativ to nature and to the condition of becoming worse natural environment. Author is searching possible causes in religion and common intelectual traditions of our western civilization. Author presents two potential solutions of ecological crisis in the next part of the dokument. The first solution is technocracy and the second one is deeply ecological, which has the point in radial chase of achal human way of life, that means in leasing pure consumer lifestyle and in society decentralization by creating mostly self-sustaining small communities.Katedra sociálních vědDokončená práce s úspěšnou obhajobo
Diagnostic value of upper gastrointestinal endoscopy prior to elective laparoscopic cholecystectomy for symptomatic cholelithiasis
No full textBackground: Laparoscopic cholecystectomy is gold standard surgery for symptomatic gall stone disease which is the commonest disease needs surgical management. Present study was conducted to contribute UGI endoscopy as routine preoperative investigation and the importance of UGI endoscopy to evaluate the association between gastrointestinal symptoms with gallstones and reduce the prevalence of post cholecystectomy pain.Methods: Patients with Ultrasonography suggestive of single or multiple gall stones were included and investigated as per proforma. Upper GI Scopy was done 1 to 2 days prior to laparoscopic cholecystectomy as per inclusion and exclusion criteria. All patients above 18years, with ultrasonographically proven diagnosis of cholelithiasis and with symptoms (typical and atypical) were included.Results: In present study, author have evaluated the different OGD pathologies the most common site of pathology was stomach (72.5%) that was gastritis. Followed by oesophagitis (55%), and Hiatus hernia (16.5) The most common duodenal pathology was duodenitis (6.25%). In present study, 71 patients had pain in epigastrium at presentation which gradually subsided with no complains of pain in 3 months. Statistically significant reduction in pain was appraised at the end of first week itself (p-value <0.0001).Conclusions: Certain symptoms associated with gallstones are not alleviated by cholecystectomy itself and requires further exploration, therefore, patients presenting with symptomatic gall stone disease should undergo routine OGD prior to cholecystectomy as many gastrointestinal lesions may coexist which prevents the complete relief of the symptoms after cholecystectomy.</jats:p
