606 research outputs found
Is anthropogenic sea level fingerprint already detectable in the Pacific ocean ?
Sea level rates up to three times the global mean rate are being observed in the western tropical Pacific since 1993 by satellite altimetry. From recently published studies, it is not yet clear whether the sea level spatial trend patterns of the Pacific Ocean observed by satellite altimetry are mostly due to internal climate variability or if some anthropogenic fingerprint is already detectable. A number of recent studies have shown that the removal of the signal corresponding to the Pacific Decadal Oscillation (PDO)/Interdecadal Pacific Oscillation (IPO) from the observed altimetry sea level data over 1993–2010/2012 results in some significant residual trend pattern in the western tropical Pacific. It has thus been suggested that the PDO/IPO-related internal climate variability alone cannot account for all of the observed trend patterns in the western tropical Pacific and that the residual signal could be the fingerprint of the anthropogenic forcing. In this study, we investigate if there is any other internal climate variability signal still present in the residual trend pattern after the removal of IPO contribution from the altimetry-based sea level over 1993–2013. We show that subtraction of the IPO contribution to sea level trends through the method of linear regression does not totally remove the internal variability, leaving significant signal related to the non-linear response of sea level to El Niño Southern Oscillation (ENSO). In addition, by making use of 21 CMIP5 coupled climate models, we study the contribution of external forcing to the Pacific Ocean regional sea level variability over 1993–2013, and show that according to climate models, externally forced and thereby the anthropogenic sea level fingerprint on regional sea level trends in the tropical Pacific is still too small to be observable by satellite altimetry
Zenith: Utility-Aware Resource Allocation for Edge Computing
In the Internet of Things(IoT) era, the demands for low-latency computing for time-sensitive applications (e.g., location-based augmented reality games, real-time smart grid management, real-time navigation using wearables) has been growing rapidly. Edge Computing provides an additional layer of infrastructure to fill latency gaps between the IoT devices and the back-end computing infrastructure. In the edge computing model, small-scale micro-datacenters that represent ad-hoc and distributed collection of computing infrastructure pose new challenges in terms of management and effective resource sharing to achieve a globally efficient resource allocation. In this paper, we propose Zenith, a novel model for allocating computing resources in an edge computing platform that allows service providers to establish resource sharing contracts with edge infrastructure providers apriori. Based on the established contracts, service providers employ a latency-aware scheduling and resource provisioning algorithm that enables tasks to complete and meet their latency requirements. The proposed techniques are evaluated through extensive experiments that demonstrate the effectiveness, scalability and performance efficiency of the proposed model
Plant polysaccharides for protein binding
Polysaccharides are polymeric carbohydrates that are made up of many monosaccharide units linked together by glycosidic linkages. They are architecturally complex biomacromolecules because of the different monosaccharides and their infinite ways to form the building blocks with each other
Cultivation of microalgae spirulina platensis biomass using palm oil mill effluent for phycocyanin productivity and future biomass refinery attributes
Palm oil mill effluent is a type of wastewater which contains a high concentration of organic nitrogen, phosphorus, and different supplement substances. These substances support and enhance the growth of microalgae. Cyanobacteria Spirulina platensis is a blue-green microalga with two phycobiliproteins as its primary constituents. Phycocyanin is a natural blue colourant used in biomedicines, cosmetics, diagnostics, treatments, and environmental protection. Chlorophyll pigment plays a significant role in photosynthesis where the photosynthetic process uses atmospheric carbon to produce starch and lipid which can eventually be converted into desirable products such as biodiesel. Therefore, in this study, Spirulina platensis was cultivated in different concentrations of diluted POME (10-50%, ) at °C room temperature, 90 μmol photon m-2 s-1, and aerated for 24 h continuously. The growth of Spirulina platensis was monitored through optical density at 680 nm for 15 days. The highest biomass yield obtained in the control medium and 30% POME medium were and  g/L, respectively. The highest phycocyanin yield obtained from the biomass harvested from 30% nutrient media was  mg and followed by  mg from control media with purified phycocyanin of  mg and  mg, respectively. The peak properties of phycocyanin such as the amide group at 1655.17 cm-1 (C=O stretching), FT-IR analysis revealed well-formed Spirulina platensis with all characteristic peaks and distinct fingerprints of phycocyanin. The ultrasound method produces the highest lipid yield (%) which consists of stearic (38.45%), palmitoleic (), and palmitic () fatty acid methyl esters. The FAME produced from the extracted lipid has the potential to be used in biodiesel applications. Since POME contains the essential nutrients which can support the growth of Spirulina platensis in the optimum environment for biomass and lipid productivity, it revealed the potential for biodiesel production
Alternative Translocation Breakpoint Cluster Region 5' to BCL-6 in B-cell Non-Hodgkin’s Lymphoma
Chromosomal translocations involving band 3q27 with various different partner chromosomes represent a recurrent cytogenetic abnormality
in B-cell non-Hodgkin’s lymphoma. In a fraction of these translocations,
the chromosomal breakpoint is located within the 5' noncoding region of
the BCL-6 proto-oncogene where the BCL-6 major breakpoint region
(MBR) maps. As a result of the translocation, BCL-6 expression is deregulated by promoter substitution. However, between 30 and 50% of lymphomas with cytogenetically detectable translocations affecting band 3q27
retain a germ-line configuration at the BCL-6 locus. To identify possible
additional breakpoint clusters within 3q27, we cloned a t(3;14)(q27;q32)
lymphoma without MBR rearrangement and found a novel breakpoint
site located between 245 and 285 kb 5' to BCL-6. Breakpoints within this
newly described region, which we called the alternative breakpoint region
(ABR), were found to be recurrent in lymphomas carrying t(3q27) chromosomal translocations but devoid of BCL-6 MBR rearrangements. Comparative analysis of multiple lymphomas carrying rearrangements within
the ABR showed that the breakpoints cluster within a 20-kb distance.
Translocations involving the ABR may juxtapose BCL-6 to distantly
acting, heterologous transcriptional regulatory elements which cause deregulation of the proto-oncogene. The identification of BCL-6 ABR provides new tools for the diagnosis of lymphomas carrying aberrations at
3q27 and deregulated BCL-6 genes
Alternative Translocation Breakpoint Cluster Region 5' to BCL-6 in B-cell Non-Hodgkin’s Lymphoma
Chromosomal translocations involving band 3q27 with various different partner chromosomes represent a recurrent cytogenetic abnormality
in B-cell non-Hodgkin’s lymphoma. In a fraction of these translocations,
the chromosomal breakpoint is located within the 5' noncoding region of
the BCL-6 proto-oncogene where the BCL-6 major breakpoint region
(MBR) maps. As a result of the translocation, BCL-6 expression is deregulated by promoter substitution. However, between 30 and 50% of lymphomas with cytogenetically detectable translocations affecting band 3q27
retain a germ-line configuration at the BCL-6 locus. To identify possible
additional breakpoint clusters within 3q27, we cloned a t(3;14)(q27;q32)
lymphoma without MBR rearrangement and found a novel breakpoint
site located between 245 and 285 kb 5' to BCL-6. Breakpoints within this
newly described region, which we called the alternative breakpoint region
(ABR), were found to be recurrent in lymphomas carrying t(3q27) chromosomal translocations but devoid of BCL-6 MBR rearrangements. Comparative analysis of multiple lymphomas carrying rearrangements within
the ABR showed that the breakpoints cluster within a 20-kb distance.
Translocations involving the ABR may juxtapose BCL-6 to distantly
acting, heterologous transcriptional regulatory elements which cause deregulation of the proto-oncogene. The identification of BCL-6 ABR provides new tools for the diagnosis of lymphomas carrying aberrations at
3q27 and deregulated BCL-6 genes
Impact of biomass density on growth rates of spirulina platensis under distinct light spectra
Light is the core environmental factor that affects the growth and biomass production of microalgae. However, the high density of microalgae will lead to reduction of the growth rate of microalgae culture due to availability of light decreases. Therefore, this experiment was conducted with aim of determining the influence of biomass density on growth of Spirulina platensis under different density of culture and LED lights. The result found that, the growth rate Spirulina platensis was reduced under high biomass density (9:1) due to lacking light penetration into the culture. However, white LED helps maintain the light acclimation process in the cells. Light spectra enhance the growth biomass. However white light contains all the light spectra highly contribute to the biomass production. The maximum light was penetrated into the culture due to minimal density of culture. More light was observed by the cells. Photosynthetic microalage may frequently experience irradiance fluctuations of one to two orders of magnitude in the natural environment. Microalgae have created several acclimation mechanisms to deal with such shifts
Uptake and Accumulation of Oxidized Low-Density Lipoprotein during Mycobacterium tuberculosis Infection in Guinea Pigs
The typical host response to infection of humans and some animals by M. tuberculosis is the accumulation of reactive oxygen species generating inflammatory cells into discrete granulomas, which frequently develop central caseous necrosis. In previous studies we showed that infection of immunologically naïve guinea pigs with M. tuberculosis leads to localized and systemic oxidative stress that results in a significant depletion of serum total antioxidant capacity and the accumulation of malondialdehyde, a bi-product of lipid peroxidation. Here we show that in addition, the generation of excessive reactive oxygen species in vivo resulted in the accumulation of oxidized low density lipoproteins (OxLDL) in pulmonary and extrapulmonary granulomas, serum and lung macrophages collected by bronchoalveolar lavage. Macrophages from immunologically naïve guinea pigs infected with M. tuberculosis also had increased surface expression of the type 1 scavenger receptors CD36 and LOX1, which facilitate the uptake of oxidized host macromolecules including OxLDL. Vaccination of guinea pigs with Bacillus Calmette Guerin (BCG) prior to aerosol challenge reduced the bacterial burden as well as the intracellular accumulation of OxLDL and the expression of macrophage CD36 and LOX1. In vitro loading of guinea pig lung macrophages with OxLDL resulted in enhanced replication of bacilli compared to macrophages loaded with non-oxidized LDL. Overall, this study provides additional evidence of oxidative stress in M. tuberculosis infected guinea pigs and the potential role OxLDL laden macrophages have in supporting intracellular bacilli survival and persistence
Economical cultivation system of microalgae Spirulina platensis for lipid production
The marine algae Spirulina platensis was cultured in a medium of palm oil mill effluent (POME) and the production of lipid in the biomass was optimized. Among 7 species Spirulina platensis was isolated from the marine sample which have greater lipid potential was collected from Pantai Teluk Cempedak, Kuantan which is located at East Coast region of Pahang state. At 28+2 °C, the maximum lipid content in the biomass harvested at the end of a 15 days batch culture was quantified with the following values of the experimental factors: POME concentration with (10%, 20% and 30%) (v/v) and light intensity (3,000 lux, 4,000 lux, 5,000 lux). Under the optimized conditions with 20% of POME, the maximum dry mass concentration of the was 754.5 mg L−1 with lipid 34.5% production on day 13 of a batch culture, declining to ∼687 mg L−1 on day 15. At 5,000 lux light intensities, the maximum yield obtained was 854.6 mg L−1 with lipid 35.8% production on day 14, it declined to 732.8 mg L−1 on day 15
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