976 research outputs found
Increased tolerance of Litopenaeus vannamei to white spot syndrome virus (WSSV) infection after oral application of the viral envelope protein VP28
It has been generally accepted that invertebrates such as shrimp do not have an adaptive immune response system comparable to that of vertebrates. However, in the last few years, several studies have suggested the existence of such a response in invertebrates. In one of these studies, the shrimp Penaeus monodon showed increased protection against white spot syndrome virus (WSSV) using a recombinant VP28 envelope protein of WSSV. In an effort to further investigate whether this increased protection is limited to P. monodon or can be extended to other penaeid shrimp, experiments were performed using the Pacific white shrimp Litopenaeus vannamei. As found with P. monodon, a significantly lower cumulative mortality for VP28-fed shrimp was found compared to the controls. These experiments demonstrate that there is potential to use oral application of specific proteins to protect the 2 most important cultured shrimp species, P. monodon and L. vannamei, against WSSV. Most likely, this increased protection is based on a shared and, therefore, general defence mechanism present in all shrimp species. This makes the design of intervention strategies against pathogens based on defined proteins a viable option for shrimp cultur
Energy, Obsolescence, and the Productivity Slowdown
The growth rate of output per worker in the U.S. declined sharply during the 1970's. A leading explanation of this phenomenon holds that the dramatic rise in energy prices during the 1970's caused a significant portion of the U.S. capital stock to become obsolete. This led to a decline in effective capital input which, in turn, caused a reduction in the reduction in the growth rate of output per worker. This paper examines a key prediction of this hypothesis. If there is a significant link between energy and capital obsolescence, it should be revealed in the market price of used capital: if rising energy costs did in fact render older, energy-inefficient capital obsolete, prospective buyers should have reduced the price that they were willing to pay for that capital. An examination of the market for used capital before and after the energy price shocks should thus reveal the presence and magnitude of the obsolescence effect. We have carried out this examination for four types of used machine tools and five types of construction equipment. We did not find a general reduction in the price of used equipment after the energy price shocks. Indeed, the price of used construction equipment - the more energy intensive of our two types of capital - tended to increase after 1973. We thus conclude that our data do not support the obsolescence explanation of the productivity of slowdown.
Apollo Saturn 511 effluent measurements from the Apollo 16 launch operations: An experiment
An experiment was performed in conjunction with the Apollo 16 launch to define operational and instrumentational problems associated with launch-vehicle exhaust effluent monitoring. Ground and airborne sampling were performed for CO, CO2, hydrocarbons, and particulates. Sampling systems included filter pads and photometers for particulates and whole-air grab samples for gases. Launch debris was identified in the particulate samples at ground level(taken immediately after launch) and in the airborne measurements (taken 40 to 50 minutes after launch approximately 40 km downwind of the pad). Operational problems were identified and included the need for higher instrumentation mobility and the need for real-time sampling instrumentation as opposed to collection-type samples such as the whole-air grab sample
Effluent sampling of Scout D and Delta launch vehicle exhausts
Characterization of engine-exhaust effluents (hydrogen chloride, aluminum oxide, carbon dioxide, and carbon monoxide) has been attempted by conducting field experiments monitoring the exhaust cloud from a Scout-Algol III vehicle launch and a Delta-Thor vehicle launch. The exhaust cloud particulate size number distribution (total number of particles as a function of particle diameter), mass loading, morphology, and elemental composition have been determined within limitations. The gaseous species in the exhaust cloud have been identified. In addition to the ground-based measurements, instrumented aircraft flights through the low-altitude, stabilized-exhaust cloud provided measurements which identified CO and HCI gases and Al2O3 particles. Measurements of the initial exhaust cloud during formation and downwind at several distances have established sampling techniques which will be used for experimental verification of model predictions of effluent dispersion and fallout from exhaust clouds
Evaluation of an in-clinic Serum Amyloid A (SAA) assay and assessment of the effects of storage on SAA samples
<p>Abstract</p> <p>Background</p> <p>An in-clinic assay for equine serum amyloid A (SAA) analysis, Equinostic EVA1, was evaluated for use in a clinical setting. Stability of SAA in serum samples was determined.</p> <p>Methods</p> <p>Intra- and inter- assay variation of the in-clinic method was determined. The in-clinic method (EVA1) results were compared to a reference method (Eiken LZ SAA) with 62 patient samples. For samples with SAA concentrations within the assay range of EVA1 (10-270 mg/L), differences between the methods were evaluated in a difference plot. Linearity under dilution was evaluated in two samples. Stability of SAA in three serum pools stored at 4°C and approximately 22°C was evaluated with the reference method day 0, 1, 2, 4, 7, 17 and analysed with a two-way ANOVA.</p> <p>Results</p> <p>The imprecision (coefficient of variation, CV) for the in-clinic method was acceptable at higher SAA concentrations with CV values of 7,3-12%, but poor at low SAA concentrations with CV values of 27% and 37% for intra- and inter-assay variation respectively. Recovery after dilution was 50-138%. The in-clinic assay and the reference method identified equally well horses with low (<10 mg/L) and high (>270 mg/L) SAA concentrations. Within the assay range of the in-clinic method, 10-270 mg/L, the difference between the two methods was slightly higher than could be explained by the inherent imprecision of the assays. There were no significant changes of serum SAA concentrations during storage.</p> <p>Conclusions</p> <p>The in-clinic assay identified horses with SAA concentrations of <10 mg/L and >270 mg/L in a similar way as the reference method, and provided an estimate of the SAA concentration in the range of 10-270 mg/L. The imprecision of the in-clinic method was acceptable at high SAA concentrations but not at low concentrations. Dilution of samples gave inconsistent results. SAA was stable both at room temperature and refrigerated, and thus samples may be stored before analysis with the reference method.</p
White spot syndrome virus envelope protein VP28 is involved in the systemic infection of shrimp
AbstractWhite spot syndrome virus (WSSV) is a large DNA virus infecting shrimp and other crustaceans. The virus particles contain at least five major virion proteins, of which three (VP26, VP24, and VP15) are present in the rod-shaped nucleocapsid and two (VP28 and VP19) reside in the envelope. The mode of entry and systemic infection of WSSV in the black tiger shrimp, Penaeus monodon, and the role of these proteins in these processes are not known. A specific polyclonal antibody was generated against the major envelope protein VP28 using a baculovirus expression vector system. The VP28 antiserum was able to neutralize WSSV infection of P. monodon in a concentration-dependent manner upon intramuscular injection. This result suggests that VP28 is located on the surface of the virus particle and is likely to play a key role in the initial steps of the systemic WSSV infection in shrimp
A global scavenging and circulation ocean model of thorium-230 and protactinium-231 with improved particle dynamics (NEMO–ProThorP 0.1)
In this paper we set forth a 3-D
ocean model of the radioactive trace isotopes 230Th
and 231Pa. The interest arises from the fact that these isotopes
are extensively used for investigating particle transport in the ocean and
reconstructing past ocean circulation. The tracers are reversibly scavenged
by biogenic and lithogenic particles.Our simulations of 230Th and 231Pa are based on the
NEMO–PISCES ocean biogeochemistry general circulation model, which includes
biogenic particles, namely small and big particulate organic carbon, calcium
carbonate and biogenic silica. Small and big lithogenic particles from dust
deposition are included in our model as well. Their distributions generally
compare well with the small and big lithogenic particle concentrations from
recent observations from the GEOTRACES programme, except for boundary
nepheloid layers for which, as of today, there are no non-trivial
prognostic models available on a global scale. Our simulations reproduce
230Th and 231Pa dissolved concentrations: they compare
well with recent GEOTRACES observations in many parts of the ocean.
Particulate 230Th and 231Pa concentrations are
significantly improved compared to previous studies, but they are still too
low because of missing particles from nepheloid layers. Our simulation
reproduces the main characteristics of the 231Pa∕230Th ratio
observed in the sediments and supports a moderate affinity of
231Pa to biogenic silica as suggested by recent observations
relative to 230Th.Future model development may further improve understanding, especially when
this will include a more complete representation of all particles, including
different size classes, manganese hydroxides and nepheloid layers. This can
be done based on our model as its
source code is readily available.</p
Rosiglitazone and Fenofibrate Additive Effects on Lipids
Background. To evaluate the effect of rosiglitazone, fenofibrate, or their combined use on plasma lipids in normoglycemic healthy adults. Methods and Results. Subjects were randomized in a double-blind fashion to rosiglitazone + placebo, fenofibrate + placebo, rosiglitazone + fenofibrate, or matching double placebo. The between-group difference in the change in fasting TG, high-density lipoprotein cholesterol (HDL-C), LDL-C, and plasma apolipoproteins A-I, A-II, and C-III level were compared after 12 weeks of treatment. A total of 548 subjects were screened and 41 met the inclusion criteria. After 12 weeks of therapy, the median change in the triglyceride levels showed a significant reduction ranging from 47 to 55 mg per deciliter in the fenofibrate only and rosiglitazone/fenofibrate groups compared with placebo (P = 0.0496). However, the rosiglitazone only group did not show significant change in triglyceride level. The change in the Apo AII showed increase in all the treatment groups compared with placebo (P = 0.009). There was also significant change in the Apo CIII that showed reduction of its level in the fenofibrate only and rosiglitazone/fenofibrate groups (P = 0.0003). Conclusion. Rosiglitazone does not appear to modulate hypertriglyceridemia in patients with elevated triglycerides independent of glucose metabolism
Priming of plant innate immunity by rhizobacteria and beta-aminobutyric acid: differences and similarities in regulation
P>Pseudomonas fluorescens WCS417r bacteria and beta-aminobutyric acid can induce disease resistance in Arabidopsis, which is based on priming of defence. In this study, we examined the differences and similarities of WCS417r- and beta-aminobutyric acid-induced priming. Both WCS417r and beta-aminobutyric acid prime for enhanced deposition of callose-rich papillae after infection by the oomycete Hyaloperonospora arabidopsis. This priming is regulated by convergent pathways, which depend on phosphoinositide- and ABA-dependent signalling components. Conversely, induced resistance by WCS417r and beta-aminobutyric acid against the bacterial pathogen Pseudomonas syringae are controlled by distinct NPR1-dependent signalling pathways. As WCS417r and beta-aminobutyric acid prime jasmonate- and salicylate-inducible genes, respectively, we subsequently investigated the role of transcription factors. A quantitative PCR-based genome-wide screen for putative WCS417r- and beta-aminobutyric acid-responsive transcription factor genes revealed distinct sets of priming-responsive genes. Transcriptional analysis of a selection of these genes showed that they can serve as specific markers for priming. Promoter analysis of WRKY genes identified a putative cis-element that is strongly over-represented in promoters of 21 NPR1-dependent, beta-aminobutyric acid-inducible WRKY genes. Our study shows that priming of defence is regulated by different pathways, depending on the inducing agent and the challenging pathogen. Furthermore, we demon-strated that priming is associated with the enhanced expression of transcription factors. New Phytologist (2009) 183: 419-431doi: 10.1111/j.1469-8137.2009.02851.x
The white spot syndrome virus DNA genome sequence
AbstractWhite spot syndrome virus (WSSV) is at present a major scourge to worldwide shrimp cultivation. We have determined the entire sequence of the double-stranded, circular DNA genome of WSSV, which contains 292,967 nucleotides encompassing 184 major open reading frames (ORFs). Only 6% of the WSSV ORFs have putative homologues in databases, mainly representing genes encoding enzymes for nucleotide metabolism, DNA replication, and protein modification. The remaining ORFs are mostly unassigned, except for five, which encode structural virion proteins. Unique features of WSSV are the presence of a very long ORF of 18,234 nucleotides, with unknown function, a collagen-like ORF, and nine regions, dispersed along the genome, each containing a variable number of 250-bp tandem repeats. The collective information on WSSV and the phylogenetic analysis on the viral DNA polymerase suggest that WSSV differs profoundly from all presently known viruses and that it is a representative of a new virus family
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