Rat liver membrane preparations

The quality of rat liver plasma membranes was examined using three different methods of preparation. Hypotonic Ca++-free preparation media were compared with hypotonic Ca++ media and with isotonic Ca++ media. The plasma membranes prepared in hypotonic Ca++ free media were as pure or better than the other two preparation types, while the (Na+K+)-MgATPase, MgATPase, and the ADPase specific activities were higher. The AMPase specific activities were of similar value for all three types of preparation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34040/1/0000317.pd

The Role of Bacillus amyloliquefaciens on Litopenaeus vannamei During the Maturation of a Biofloc System

[EN] Biofloc technology is a sustainable aquaculture production system which uses microorganisms to maintain water quality and to increase productivity. In this system, probiotics can enhance the positive effects of bioflocs on the cultured species. The objective of this research is to study the role of the probiotic bacterium Bacillus amyloliquefaciens during the formation of a biofloc system for the culture of Litopenaeus vannamei. Two doses of probiotic were assayed and applied directly to the water. The experiment was developed in nine tanks distributed as follows: Three control tanks with no probiotic, three tanks with a probiotic dose of 103 cfu/mL, and three tanks with a dose of 104 cfu/mL. Water quality, microbial activity, growth parameters and the immune system state of shrimps were monitored throughout the maturation process. The results indicate a positive effect upon the shrimp immune system throughout the study period, where specifically there was an increase in granular hemocytes in the shrimp hemolymph. During the immature biofloc phase, granular hemocytes were 5% higher in tanks supplemented with the probiotic. During the mature biofloc phase, granular hemocytes were 7% higher in those same tanks. During the maturation of the biofloc, environmental conditions are more unfavorable for shrimp growth, due to the accumulation of nitrites. So, the effect of the probiotic is especially important during this stage when the shrimp are stressed and are more vulnerable to diseases. However, the effects on microbial activity, water quality and Litopenaeus vannamei growth did not increase the benefits of the biofloc system.This research has been funded by the pre-doctoral program VALi + D from the Conselleria d'Educacio, Investigacio, Cultura i Esports (Generalitat Valenciana), file number ACIF/2014/244.Llario, F.; Falco, S.; Sebastiá-Frasquet, M.; Escrivá-Perales, J.; Rodilla, M.; Da Silva-Poersch, LH. (2019). The Role of Bacillus amyloliquefaciens on Litopenaeus vannamei During the Maturation of a Biofloc System. Journal of Marine Science and Engineering. 7:228-244. https://doi.org/10.3390/jmse7070228S228244

Essential roles of three enhancer sites in σ54-dependent transcription by the nitric oxide sensing regulatory protein NorR

The bacterial activator protein NorR binds to enhancer-like elements, upstream of the promoter site, and activates σ54-dependent transcription of genes that encode nitric oxide detoxifying enzymes (NorVW), in response to NO stress. Unique to the norVW promoter in Escherichia coli is the presence of three enhancer sites associated with a binding site for σ54-RNA polymerase. Here we show that all three sites are required for NorR-dependent catalysis of open complex formation by σ54-RNAP holoenzyme (Eσ54). We demonstrate that this is essentially due to the need for all three enhancers for maximal ATPase activity of NorR, energy from which is used to remodel the closed Eσ54 complex and allow melting of the promoter DNA. We also find that site-specific DNA binding per se promotes oligomerisation but the DNA flanking the three sites is needed to further stabilise the functional higher order oligomer of NorR at the enhancers

Essential roles of three enhancer sites in σ54-dependent transcription by the nitric oxide sensing regulatory protein NorR

The bacterial activator protein NorR binds to enhancer-like elements, upstream of the promoter site, and activates σ54-dependent transcription of genes that encode nitric oxide detoxifying enzymes (NorVW), in response to NO stress. Unique to the norVW promoter in Escherichia coli is the presence of three enhancer sites associated with a binding site for σ54-RNA polymerase. Here we show that all three sites are required for NorR-dependent catalysis of open complex formation by σ54-RNAP holoenzyme (Eσ54). We demonstrate that this is essentially due to the need for all three enhancers for maximal ATPase activity of NorR, energy from which is used to remodel the closed Eσ54 complex and allow melting of the promoter DNA. We also find that site-specific DNA binding per se promotes oligomerisation but the DNA flanking the three sites is needed to further stabilise the functional higher order oligomer of NorR at the enhancers

Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom

Primary Coenzyme Q Deficiency in Pdss2 Mutant Mice Causes Isolated Renal Disease

Coenzyme Q (CoQ) is an essential electron carrier in the respiratory chain whose deficiency has been implicated in a wide variety of human mitochondrial disease manifestations. Its multi-step biosynthesis involves production of polyisoprenoid diphosphate in a reaction that requires the enzymes be encoded by PDSS1 and PDSS2. Homozygous mutations in either of these genes, in humans, lead to severe neuromuscular disease, with nephrotic syndrome seen in PDSS2 deficiency. We now show that a presumed autoimmune kidney disease in mice with the missense Pdss2kd/kd genotype can be attributed to a mitochondrial CoQ biosynthetic defect. Levels of CoQ9 and CoQ10 in kidney homogenates from B6.Pdss2kd/kd mutants were significantly lower than those in B6 control mice. Disease manifestations originate specifically in glomerular podocytes, as renal disease is seen in Podocin/cre,Pdss2loxP/loxP knockout mice but not in conditional knockouts targeted to renal tubular epithelium, monocytes, or hepatocytes. Liver-conditional B6.Alb/cre,Pdss2loxP/loxP knockout mice have no overt disease despite demonstration that their livers have undetectable CoQ9 levels, impaired respiratory capacity, and significantly altered intermediary metabolism as evidenced by transcriptional profiling and amino acid quantitation. These data suggest that disease manifestations of CoQ deficiency relate to tissue-specific respiratory capacity thresholds, with glomerular podocytes displaying the greatest sensitivity to Pdss2 impairment