2,049 research outputs found
Digging Up the Dirt: China\u27s Exploitation of Transgenic Seed Approvals
In 2013, China rejected shipments of U.S. corn imports due to the presence of an unapproved transgenic trait, creating an international trade disruption that sent ripples throughout the U.S. agriculture industry and grain markets. Syngenta, the seed company that began selling the trait to U.S. farmers prior to receiving China\u27s import approval, largely shouldered the blame. U.S. farmers held Syngenta singularly liable and initiated a class action in an attempt to force Syngenta to pay for the drop in grain prices due to the disruption. The highly publicized domestic legal dispute left China\u27s opportunistic actions largely unnoticed. The time has come to provide context to the circumstances surrounding China\u27s actions in the 2013 trade fiasco. The United States can no longer ignore China\u27s international trade violations, especially in light of the drastic consequences of the class action lawsuit. Holding Syngenta liable without addressing China\u27s delinquent regulatory system will set a dangerous precedent for seed companies and threaten the future of agricultural innovation. This Comment argues that the United States should file a World Trade Organization complaint against China for its violations of international trade agreements to ensure that agricultural technology companies can make informed commercialization decisions and deliver U.S. farmers needed products without fear of future international trade disruptions
Groeiende ruimtebehoefte boskoopse boomteelt
De regio Boskoop is al eeuwenlang het centrum voor de boomteelt in Nederland en Europa. In het kader van de streekplanherziening Zuid-Holland Oost is in opdracht van het Platform Sierteelt Regio Boskoop op basis van trends uit het verleden en de verwachte, toekomstige ontwikkelingen in de boomteeltsector een schatting gemaak van de toekomstige ruimtebehoefte voor de boomteelt in de regio Boskoop
Design of a trans protease lentiviral packaging system that produces high titer virus
<p>Abstract</p> <p>Background</p> <p>The structural and enzymatic proteins of the human immunodeficiency virus (HIV) are initially generated as two long polyproteins encoded from overlapping reading frames, one producing the structural proteins (Gag) and the second producing both structural and enzymatic proteins (Gag-Pol). The Gag to Gag-Pol ratio is critical for the proper assembly and maturation of viral particles. To minimize the risk of producing a replication competent lentivirus (RCL), we developed a "super-split" lentiviral packaging system in which Gag was separated from Pol with minimal loss of transducibility by supplying protease (PR) <it>in trans </it>independently of both Gag and Pol.</p> <p>Results</p> <p>In developing this "super-split" packaging system, we incorporated several new safety features that include removing the Gag/Gag-Pol frameshift, splitting the Gag, PR, and reverse transcriptase/integrase (RT/IN) functions onto separate plasmids, and greatly reducing the nucleotide sequence overlap between vector and Gag and between Gag and Pol. As part of the construction of this novel system, we used a truncated form of the accessory protein Vpr, which binds the P6 region of Gag, as a vehicle to deliver both PR and RT/IN as fusion proteins to the site of viral assembly and budding. We also replaced <it>wt </it>PR with a slightly less active T26S PR mutant in an effort to prevent premature processing and cytoxicity associated with <it>wt </it>PR. This novel "super-split" packaging system yielded lentiviral titers comparable to those generated by conventional lentiviral packaging where Gag-Pol is supplied intact (1.0 × 10<sup>6 </sup>TU/ml, unconcentrated).</p> <p>Conclusion</p> <p>Here, we were able to create a true "split-function" lentiviral packaging system that has the potential to be used for gene therapy applications. This novel system incorporates many new safety features while maintaining high titers. In addition, because PR is supplied <it>in trans</it>, this unique system may also provide opportunities to examine viral protein processing and maturation.</p
Effects of Polychlorinated Biphenyl Compounds and Proposed PCB-Replacement Products on Embryo-Larval Stages of Fish and Amphibians
Static renewal bioassays were performed with four polychlorinated biphenyls, including Capacitor 21 and Aroclors 1016, 1242, and 1254. Each compound was used to treat embryo-larval stages of the rainbow trout (Salmo gairdneri), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), redear sunfish (Lepomis microlophus), leopard frog (Rana pipiens), Fowler\u27s toad (Bufo fowleri), and American toad (Bufo americanus). Developmental stages of the trout were the most sensitive, with LC50 \u27s at 4 days posthatching of 0.3, 1.0, 1.1, and 1.6 μg/l for Aroclors 1254, 1242, 1016, and Capacitor 21, respectively. LC1\u27s ranged between 0.009-0.011 μg/l. Fowler\u27s toad was the most tolerant species, and LC50 \u27s varied from 3.7-28.0 μg/l. Toxicity of the PCB\u27s generally increased with percent chlorine substitution.
Bioassays also were conducted with dioctylphthalate (D0P), diisononylphthalate, and Dow Corning 561 silicone, three products proposed as replacements for PCB\u27s. Embryos and larvae of the channel catfish, redear sunfish, leopard frog, and Fowler\u27s toad were exposed through 4 days posthatching. Catfish was the most sensitive species, and sunfish was the most resistant. Based on LC50 values, replacement products were found to be 2-5 orders of magnitude less toxic than PCB\u27s.
Continuous flow embryo-larval bioassays were performed on Capacitor 21 and DOP. Test species included redear sunfish, rainbow trout, and largemouth bass (Micropterus salmoides). Paralleling results from static renewal tests, flow-through data reflected a vast difference in toxicity between PCB\u27s and potential replacements, and good data correlation was achieved between the two bioassay procedures
Bomen over ruimte: een studie naar de toekomstige ruimtebehoefte voor de boomteelt in de regio Boskoop
In het kader van de streekplanherziening Zuid-Holland Oost is een schatting gemaakt van de toekomstige ruimtebehoefte voor de boomteelt in de regio Boskoop tot 2015. Op basis van toekomstige ontwikkelingen in de vraag naar boomteeltproducten, de (inter)nationale concurrentiepositie van de boomteelt in de regio Boskoop en de bedrijfsstructuur is de extra ruimtebehoefte geschat op 2% per jaar. Het totale areaal boomteelt in 2015 komt hiermee op 1.435 ha (+ 335 ha), waarvan de helft pot- en containerteelt en de helft in de vollegrond. Ook zal tot 2015 de teelt onder glas gestaag toenemen. Om het boomteeltcentrum in de regio Boskoop in stand te houden is niet alleen behoefte aan extra ruimte, maar zal ook voldaan moeten worden aan een aantal kwalitatieve randvoorwaarden. De belangrijkste randvoorwaarden zijn: planologische zekerheid, ruimte voor ondersteunend glas, goede bedrijfsstructuur, goede infrastructuur, kwalitatief goed opgeleid personeel en professioneel ondernemersscha
Sensitivity of Vertebrate Embryos to Heavy Metals as a Criterion of Water Quality: Phase III: Use of Fish and Amphibian Eggs as Bioindicator Organisms for Evaluating Water Quality
Fish and amphibian eggs, embryos and early posthatched (larval) stages were evaluated as bioindicator organisms with which to monitor the quality of natural water resources. Eggs of 9 species were cultured in water collected from each of 11 Inner Bluegrass rivers and streams. The latter were chosen to represent water sources varying in quality from extremely poor to good. Selection was based on the sources and magnitude of pollution, and the diversity and density of piscine populations. Cultures were maintained in vitro, using 12-hour changes of water.
Averaging data for all 9 animal species, egg hatchability (embryonic survival) ranged from 0% for the most contaminated water to 94% for uncontaminated water found to support a healthy aquatic biota. Eggs of the squirrel treefrog and gray treefrog were the most sensitive of 5 amphibian species tested, and of 4 fish species, rainbow trout eggs proved most susceptible to water contaminants
Geometric realizations of generalized algebraic curvature operators
We study the 8 natural GL equivariant geometric realization questions for the
space of generalized algebraic curvature tensors. All but one of them is
solvable; a non-zero projectively flat Ricci antisymmetric generalized
algebraic curvature is not geometrically realizable by a projectively flat
Ricci antisymmetric torsion free connection
Feeding and growth of a dyke-laccolith system (Elba Island, Italy) from AMS and mineral fabric data
Dykes feed laccoliths and sills; however, the link between feeder and intrusion is rarely observed. The felsic San Martino laccolith displays a clear feeder–intrusion link, allowing reconstruction of the influence of the size and location of feeder dykes on magma flow during formation of subhorizontal intrusions. This work uses anisotropy of magnetic susceptibility (AMS) combined with mineral shape-preferred orientations of sanidine megacrysts to examine magma flow pathways through feeders into a laccolith. Strong correlation between AMS and K-feldspar datasets indicates that alteration affecting the paramagnetic mineralogy did not influence AMS results. The well-established field relationships between feeder and laccolith provided a robust ‘geo-logical’ model for flow pathways that we have used as a framework to aid interpretation of AMS data. The position and size of the main feeder dyke helped to predict the flow paths in the overlying laccolith. Our results show that magma spread laterally from the feeding system and built the laccolith layers with propagating and inflating divergent flow where tabular particles became aligned perpendicular to the magma displacement direction. The lack of internal discontinuities indicates that the magma was injected as a single pulse or a series of quickly coalescing pulses
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An investigation into the effectiveness of the test and trace system for the SARS-CoV-2 pandemic within the UK
The investigation of the UK Test and Trace system illustrated that policies enforced were not sufficient to prevent the spread of SARS-CoV-2 in the UK. Some of the shortcomings included the app, the introduction to curfews and policies in hospitality sector, the methods of reporting COVID related deaths, restriction of movements across the border and adherence from the public. Other countries such as Japan and New Zealand implemented effective contact tracing systems due to the promotion of contact tracing and adherence to the policies created. These countries also had more preventive measures in place such as reducing attendees at school and enforcing the use of contact tracing for all industries. The Netherlands could also use more preventative measure to reduce cases, since there was a similar number of cases to the UK per 1 million in the population, however the mortality rate in the UK is double that of the Netherlands. To determine why, more research into pre-existing health conditions and obesity would need to be conducted to provide evidence into whether these factors effect mortality rates in SARS-CoV-2 cases. Research into other countries contact tracing systems can provide more possibilities for improvement
Sensitivity of Vertebrate Embryos to Heavy Metals as a Criterion of Water Quality, Phase II: Bioassay Procedures Using Developmental Stages as Test Organisms
Chick, amphibian, and fish embryos were evaluated as bioassay and bioindicator organisms. Test procedures were developed by which embryonic stages may be used 1) in bioassay systems to evaluate the toxicity of particular metallic or metal-containing trace contaminants, and 20 as bioindicators to monitor the quality of natural water resources.
A bioassay technique was devised in which metallic toxicants were administered to chick embryos by needle tract injection into the yolk sac. This provided more uniform distribution of test metals throughout the yolk mass than can be obtained by conventional yolk sac injection methods, and gave more sensitivity and uniformity of test results. Metals such as arsenic, cadmium, mercury, lead and zinc are easily detectable at a level of 1 ppb.
An in vitroculture technique was developed by which embryos of aquatic vertebrates may be maintained for bioassay and bioindicator purposes. Five test species were identified, suitable synthetic culture water was formulated, and culture monitoring procedures were determined. Most toxic metals (e.g., mercury) may be detected at 1ppb or less with the use of more sensitive embryonic species (e.g., trout). Early cleavage stages of the leopard frog (Rana pipiens) proved more sensitive to cadmium than older embryos, similar to results obtained in Phase I with mercury treatment of frog embryos. Early developmental stages, therefore, have proven especially important for use in bioassay and bioindicator systems
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