1,483 research outputs found
Fungal cellulase; production and applications: minireview
Cellulose is the most abundant biomaterial derived from the living organisms on the earth; plant
is the major contributor to the cellulose pool present in the biosphere. Cellulose is used in
variety of applications ranging from nanomaterials to biofuel production. For biofuel
production, cellulose has first to be broken-down into its building blocks; β-D-glucosyl unit
which subsequently can be fermented to different product such as ethanol, acetic acids, among
others. Cellulase is the enzymatic system, which degrades cellulose chains to glucose monomers.
Cellulase is a group of three enzymes endoglucanase, exoglucanases and β-glucosidases which
act together to hydrolyze cellulose to glucose units. Cellulases are found in bacteria, fungi,
plants, and some animals. Fungi are the preferred source of cellulase for industrial applications
since they secrete large quantities of cellulase to culture medium. Despite a remarkable number
of fungi found to produce cellulase enzymes, few have been extensively investigated because they
produce large quantities of these enzymes extracellularly. In this mini-review, the production of
cellulase from fungi and the parameters affecting cellulase production are discussed briefly on light of recent publications. Furthermore, potential applications of cellulase enzymes are highlighted
The impact of trade in services on factor incomes : results from a global simulation Model
Indian gross domestic product per capita increased rapidly between 2001 and 2006 in a climate of increasing services trade, with the export-oriented services sector responsible for rising shares of growth in gross domestic product. Due to its contribution to aggregate economic growth, there is a great need for empirical examination of the distributional consequences of this growth, especially in light of the challenges in obtaining theoretical solutions that can be generalized. This paper fills this gap in the literature by using a global simulation model to examine how sensitive factor incomes across different industries may have been to the historical changes in India's services exports and imports, and provides insight on the distribution of the national income growth attributable to the expansion of the services industry. Rent on capital in the service sector and wages of all workers would have increased as a result of greater services trade in this period, while income from capital specific to agriculture and manufacturing would have declined. The factors involved with the urban-based services sector may thus benefit from the services trade growth, while the total factor income involved in rural agriculture may decline.Economic Theory&Research,Labor Policies,Trade Policy,ICT Policy and Strategies,Emerging Markets
Rejection and Critical Flux of Calcium Sulphate in a Ceramic Titanium Dioxide Nanofiltration Membrane
Microbiological profiles of Neonatal sepsis in northern Egypt
Background:This study aimed at analyzing the microbiological profile of neonatal sepsis in Egypt and to determine the antibiotic susceptibility patterns of the isolated microorganisms. Methods: Two thousand and four hundred blood samples were collected from neonates showing symptoms suggestive of septicemia, inoculated into BACT/ALERT culture bottles. Positive blood culture samples were identified and tested for antimicrobial susceptibility. Results: Among the neonates included in our study, 457 (19%) neonates were positively diagnosed with sepsis. early onset neonatal sepsis (EOS) was detected in 181 (39.6%), while late-onset neonatal sepsis (LOS) in 276 (60.4%) cases. Klebsiella pneumoniae was the most commonly isolated microorganism. Staphylococcus aureus and Enterococcus spp. were the most common isolated Gram-positive bacteria. Candida spp. was more encountered in LOS.An alarming feature of the present study is the high incidence of multidrug resistant microorganisms (65%). Among Gram negative isolates (56%) of were extended spectrum beta-lactamase (ESBL) producers and (70.5%) were carbapenem resistant. In Gram positive bacteria, resistance to methicillin in S. aureus and coagulase negative staphylococci were detected in (50%) and (41%) of isolates respectively. Additionally, 17% of Enterococcus isolates were vancomycin resistant. Coclusion: Our bacteriological profile of neonatal sepsis showed that Gram negative bacteria represented the majority of isolates. Klebsiella pneumoniae was the predominant isolate. In our study, both EOS & LOS share a nosocomial infection profile, as high antimicrobial resistance was observed among our isolates. The susceptibility profiles of the isolates may urge for the change of the current used empirical therapies
Space-Efficient Predictive Block Management
With growing disk and storage capacities, the amount of required metadata for tracking all blocks in a system becomes a daunting task by itself. In previous work, we have demonstrated a system software effort in the area of predictive data grouping for reducing power and latency on hard disks. The structures used, very similar to prior efforts in prefetching and prefetch caching, track access successor information at the block level, keeping a fixed number of immediate successors per block. While providing powerful predictive expansion capabilities and being more space efficient in the amount of required metadata than many previous strategies, there remains a growing concern of how much data is actually required. In this paper, we present a novel method of storing equivalent information, SESH, a Space Efficient Storage of Heredity. This method utilizes the high amount of block-level predictability observed in a number of workload trace sets to reduce the overall metadata storage by up to 99% without any loss of information. As a result, we are able to provide a predictive tool that is adaptive, accurate, and robust in the face of workload noise, for a tiny fraction of the metadata cost previously anticipated; in some cases, reducing the required size from 12 gigabytes to less than 150 megabytes
Microbial β-Glucosidase: sources, production and applications
Cellulose is the most abundant biopolymer in biosphere and the major constituent of plant biomass.
Cellulose polymer is made up of β-glucose units linked by β-glucosidic bonds. Cellulase is an enzymatic system that
catalyzes the hydrolysis of cellulose polymer to glucose monomers. This enzymatic system consists of three
individual enzymes namely endoglucanase, exoglucanase and β-glucosidase which act synergistically to degrade
cellulose molecules into glucose. Cellulases are produced by bacteria, fungi, plants, and animals and used in many
industrial applications such as textile industries, laundry and detergent industries, paper and pulp industry, animal
feeds, and biofuels production. β-Glucosidase is a diverse group of enzymes with wide distribution in bacteria, fungi,
plants and animals and has the potential to be utilized in various biotechnological processes such as biofuel
production, isoflavone hydrolysis, flavor enhancement and alkyl/aryl β-D-glucoside and oligosaccharides synthesis.
Thus, there is increased demand of β-glucosidase production from microbial sources under profitable industrial
conditions. In this review, β-glucosidase classification, localization, and mechanism of action will be described.
Subsequently, the various sources of β-glucosidase for industrial sector will be discussed. Moreover, Fermentation
methods and various parameters affecting β-glucosidase production will be highlighted on the light of recent
findings of different researchers. Finally, β-glucosidase applications in biofuel production, flavors enhancement,
isoflavones hydrolysis, cassava detoxification and oligosaccharide synthesis will be described
Estrogen Receptor-Beta Dependent Activities of Dietary Compounds in a Genetically Modified Rat Raphe Nuclei-Derived Cell Line
Estrogens greatly affect the activity and connectivity of serotonergic neural cell populations, which extend from clusters of nuclei in the brainstem, termed the raphe nuclei, where estrogen receptor β is the most abundantly expressed estrogen receptor subtype. Estrogenic effects on the raphe nuclei are primarily important for influencing various neuropsychological behaviors, including depression, mood swings and anxiety behaviors. Because of this connection, phases of intense hormone fluctuations for instance during menopause are often associated with several mood disturbances that often reduce the quality of life of menopausal women. Accordingly, long-term use of hormone replacement therapy appeared to be the method of choice for many menopausal women to help alleviate vasomotor symptoms, which may include neuropsychological changes such as depression. However, given the limitations and number of serious health risks attributed to hormone replacement therapy, natural compounds such as phytoestrogens are receiving widespread awareness due to their occurrence in medicinal plant extracts and a wide variety of food items including dietary supplements with respective health claims. Flavonoids, particularly the isoflavones and the naringenin-type flavanones, belong to a group of polyphenolic plant-derived secondary metabolites known to possess estrogen-like bioactivities. Nevertheless, little is known about their transactivational activity and their potential to regulate endogenous gene expression of estrogen responsive genes in the raphe nuclei due to the lack of suitable cellular models expressing sufficient amounts of functional estrogen receptor β.
Hence, a raphe nuclei-derived cell line that expresses a functional estrogen receptor β was sought as a model to investigate effects of flavonoids in vitro. In this regard, RN46A-B14 cells derived from embryonic day 13 rat medullary raphe nuclei were primarily used in this study as the main cellular model. Nonetheless, expression of endogenous estrogen receptor β in these cells was not sufficient to pursue downstream investigations of estrogen-dependent activities. To overcome this deficit, a rat raphe nuclei-derived in vitro model that overexpresses a functional estrogen receptor β was initially established (herein termed RNDA cells) by stably transducing its parent cell line, RN46A-B14 cells, with a suitable lentiviral expression vector encoding a human estrogen receptor β gene. The stable expression and the functional characterization of the transgenic receptor was confirmed by Western blot analysis and luciferase reporter gene assays, respectively. The same reporter gene assay was used to scrutinize the transactivational activity of the flavonoids in RNDA cells. Key results revealed that Genistein, Daidzein, Equol, Naringenin and 8-Prenylnaringenin demonstrated high transactivational activity in a concentration-dependent manner by stimulating luciferase expression from an estrogen responsive element-regulated reporter gene construct transiently transfected in RNDA cells. Low transactivational activity was observed in RNDA cells in response to increasing concentrations of 7-(O-prenyl)naringenin-4'-acetate. However, no transactivational activity was noticed in response to 6-(1,1-Dimethylallyl)naringenin in the studied cell model. All effects elicited by the flavonoids were antagonized by the pure estrogen receptor antagonist, Fulvestrant, indicating that all substances act by binding to and activating the transgenic ERβ. Additional effects were observed in RNDA cells in response to a co-treatment of 1 µM of either Genistein or Daidzein, but not Equol, with 10 nM 17β-Estradiol. Slight antagonistic effects were observed in the same studied cell line when either 8-Prenylnaringenin or 7-(O-prenyl)naringenin-4'-acetate, but not Naringenin or 6-(1,1-Dimethylallyl)naringenin, were co-added with 17β-Estradiol.
Results from the reporter gene assays were validated on the basis of regulation of mRNA expression of estrogen responsive genes following the global assessment of 17β-Estradiol-induced gene expression in this cell line using a DNA microarray technique. Out of 212 estrogen-regulated genes with at least two-fold change of expression, six were selected according to specific features of estrogenic regulation of expression. The expression of the six selected 17β-Estradiol-regulated genes was validated using quantitative real-time PCR analysis. The regulation of mRNA expression of the selected genes in response to the tested flavonoids was then investigated in RNDA cells. Additionally, because RNDA cells encode a temperature-sensitive mutant of the Simian Virus 40 large T-antigen, their neuronal differentiation is constitutive upon shifting them from conditions promoting proliferation (permissive temperature) to differentiation (non permissive temperature). Hence, the regulation of mRNA expression of the selected genes in response to the tested flavonoids was additionally investigated as RNDA cells differentiate.
In RNDA cells grown under proliferative conditions, 17β-Estradiol up-regulated mRNA expression of camello-like 5, sex determining region Y-box 18 and keratin type I cytoskeletal 19. Similar effects were observed in response to 8-Prenylnaringenin, Genistein, Daidzein and Equol. In addition, 17β-Estradiol down-regulated mRNA expression of neurofilament medium polypeptide and zinc finger DHHC-type containing 2. Similar effects were observed in response to 8-Prenylnaringenin, Naringenin, Genistein, Daidzein and Equol. Yet, no effect was observed on the regulation of mRNA expression of solute carrier family 6 member 4 in response to 17β-Estradiol or the flavonoids in RNDA cells grown under proliferative conditions. When RNDA cells were shifted to conditions promoting differentiation, changes in cell morphology, in mRNA expression levels and in responsiveness towards 17β-Estradiol or the flavonoids were observed. These expression studies additionally highlighted some of the genes as indicator genes for RNDA cellular differentiation.
The newly established RNDA cell line should prove useful to elucidate basic physiological properties of estrogen receptor β in the raphe nuclei. The present study should serve as the basis to help shed light on molecular and cellular mechanisms following the action of phytoestrogens, endocrine disruptors or other exogenous estrogen receptor ligands in neural cell populations, particularly the raphe nuclei, for further applications within the brain
Water Vapor Adsorption and Soil Wetting
Soil water management and irrigation practices largely depend on a timely and accurate characterization of temporal and spatial soil moisture dynamics in the root zone. Consequently, measurements and detailed information about soil water sorption, water content, behavior, and potential are required. In that concern, water vapor adsorption is an important phenomenon in arid and semi-arid regions, as well as in dry periods of tropical soils. Therefore, quantifying adsorption is important for agricultural water management, surface energy balance studies, ecological studies, and remote sensing investigations (changes in surface soil moisture content will affect land surface properties such as albedo, emissivity, and thermal inertia). The vapor pressure and isothermal adsorption of water vapor can be used to predict soil moisture adsorption capacity (Wa), specific surface area, and hydro-physical properties of arid soils such as in Egypt and in the tropical soils in Ecuador. Theory of adsorption of water vapor on soil particles is developed among the mono-molecular and poly-molecular adsorption with respect to Brunauer, Emmett, and Teller (BET) theory. Data of soil-water adsorption (W%) at different relative vapor pressures (P/Po) can be obtained for the soils, where the W% values are increased with increasing P/Po in general. The highest values of water adsorption capacity (Wa), specific surface area (S), and other hygro-physical properties such as adsorbed layers and maximum hygroscopic water are observed in the clay depths of soil profiles, while the lowest values can be found in coarse textured soils (sandy and sandy loam soils profiles). Two equations were assumed: (1) to predict P/Po at water adsorption capacity (Wa) and (2) to apply Wa in prediction of soil moisture retention, i.e., ψ (W) function at pF < 4.5
Emergency Button Application - Android Systems
The investigation of emergency situations is a complex field of study which involves different perspectives. Individual‘s and public‘s safety is a very important issue, the established emergency response system is the main core of resolving these emergency situations, we are already familiar with the normal emergency reporting system like calling 911 or using emergency phones, But this project aims to create an application that can assist users in emergency situations and provide users with instant details of their location to send to family, friends, or authorities in panic & emergency situations, another option other than public emergency phone systems and other forms of reporting in emergency situations for an easier and friendlier approach, thus improving public safety. The methodology used to complete this application is agile software development methodology which is based on iterative & incremental development that is rapid & flexible. The tools for this project include Eclipse Indigo which is a popular platform to develop Android Applications with the aid of a variety of software tools in design and user friendly software development such as Android ADT tools. In conclusion, the application‘s is successfully developed and met its main objective which is to help users broadcast their message in an emergency situation whenever they need help and can‘t easily get it or find it but with today‘s world mobile software development, public safety shall be more personalized
- …