Inactivation of baculovirus by isoflavonoids on chickpea (Cicer arietinum) leaf surfaces reduces the efficacy of nucleopolyhedrovirus against Helicoverpa armigera

Biological pesticides based on nucleopolyhedroviruses (NPVs) can provide an effective and environmentally benign alternative to synthetic chemicals. On some crops, however, the efficacy and persistence of NPVs is known to be reduced by plant specific factors. The present study investigated the efficacy of Helicoverpa armigera NPV (HearNPV) for control of H. armigera larvae, and showed that chickpea reduced the infectivity of virus occlusion bodies (OBs) exposed to the leaf surface of chickpea for at least 1 h. The degree of inactivation was greater on chickpea than that previously reported on cotton, and the mode of action is different from that of cotton. The effect was observed for larvae that consumed OBs on chickpea leaves, but it also occurred when OBs were removed after exposure to plants and inoculated onto artificial diet, indicating that inhibition was leaf surfacerelated and permanent. Despite their profuse exudation from trichomes on chickpea leaves and their low pH, organic acids—primarily oxalic and malic acid—caused no inhibition. When HearNPV was incubated with biochanin A and sissotrin, however, two minor constituents of chickpea leaf extracts, OB activity was reduced significantly. These two isoflavonoids increased in concentration by up to 3 times within 1 h of spraying the virus suspension onto the plants and also when spraying only the carrier, indicating induction was in response to spraying and not a specific response to the HearNPV. Although inactivation by the isoflavonoids did not account completely for the level of effect recorded on whole plants, this work constitutes evidence for a novel mechanism of NPV inactivation in legumes. Expanding the use of biological pesticides on legume crops will be dependent upon the development of suitable formulations for OBs to overcome plant secondary chemical effects

The Neural Mechanisms Mediating the Augmentation of Heroin Seeking Induced by Chronic Food Restriction

Addiction can be defined as a chronic relapsing disorder that is characterized by a loss of control over drug consumption. One of the major obstacles in the treatment of drug addiction is relapse, with the majority of individuals relapsing within the first year of drug abstinence. In humans, restricted food intake can modulate the main triggers of relapse thereby increasing drug craving and relapse. In animal models of relapse, caloric restriction will also increase drug seeking. The experiments presented in this thesis investigated the neuronal mechanisms that mediate the augmentation of heroin seeking induced by chronic food restriction in the rat. The mesolimbic dopamine pathway is heavily implicated in reward and motivation. Therefore, the experiments presented in Chapter 3 explored the role of dopamine in the mesolimbic pathway, specifically the nucleus accumbens, in the augmentation of heroin seeking induced by chronic food restriction. Extracellular dopamine in the nucleus accumbens core and shell subregions was differentially altered during the heroin-seeking test in chronically food restricted rats. Blockade of dopamine D1-like receptors in the nucleus accumbens shell decreased heroin seeking, whereas blockade of D1-like receptors in the nucleus accumbens core selectively reduced heroin seeking in the food restricted rats. Hormones involved in energy balance and food intake, such as leptin and ghrelin are implicated in drug-related behaviors. Thus, the experiments in Chapter 4 investigated the role of leptin and ghrelin in heroin seeking induced by chronic food restriction. As expected, chronic food restriction decreased plasma levels of leptin and increased plasma levels of ghrelin. Furthermore, administration of leptin or a ghrelin receptor antagonist into the ventral tegmental area exclusively decreased heroin seeking in the food restricted rats. These results suggest that leptin and ghrelin may modulate drug seeking by acting upstream from the mesolimbic dopamine pathway. Finally, in addition to the dense innervations from dopamine projections, the nucleus accumbens also receives a multitude of glutamatergic innervations from a variety of brain regions. Hence, in Chapter 5 we investigated the role of glutamate in the nucleus accumbens on the augmentation of heroin seeking induced by chronic food restriction. Contrary to our predictions, there were no changes in extracellular glutamate in the nucleus accumbens during ongoing heroin seeking. Moreover, administration of a glutamate receptor antagonist had no effect on heroin seeking induced by chronic food restriction. Taken together, these findings demonstrate that the augmentation of heroin seeking induced by chronic food restriction is mediated by dopamine transmission in the nucleus accumbens and can be modulated by hormones involved in metabolic processes, such as leptin and ghrelin

Augmentation of heroin seeking following chronic food restriction in the rat: A role for nucleus accumbens dopamine

Previous research using an animal model of relapse has shown that acute food deprivation will increase drug seeking. Recent evidence from humans, however, suggests that chronic food restriction rather than acute deprivation is related to increases in drug taking and relapse, emphasizing the need to develop an animal model to elucidate the mechanisms mediating the effects of chronic food restriction on drug seeking. We studied the effects of chronic food restriction during a period of abstinence on heroin seeking in rats. Results demonstrated an augmentation of heroin seeking in chronically food restricted rats with a history of heroin self-administration. Re-feeding prior to the drug seeking test or decreasing the length of the food restriction period prevented the augmentation of drug seeking. A combination of chronic food restriction and a concurrent state of hunger appear to be necessary for the augmentation of heroin seeking induced by food restriction. Previously, it was demonstrated that chronically food restricted rats display alterations in the mesolimbic dopamine system, a critical component of the reward system. Consequently, we assessed extracellular levels of dopamine in the nucleus accumbens, one of the major targets for mesolimbic dopamine neurons, during the drug seeking test, following chronic food restriction in abstinent rats with a history of heroin self-administration. Preliminary data indicate significantly higher levels of dopamine throughout the drug seeking test in the food restricted rats. Our findings suggest that food restriction-induced changes in dopamine release in the nucleus accumbens are associated with the augmentation of drug seeking in food restricted abstinent rats

The First Plague: The Denial of Water as a Forcible Transfer under International Humanitarian Law

Article published in the Michigan State International Law Review

A data administration support system

Collage of different postage stamps arranged in rows.https://commons.und.edu/uac-all/3958/thumbnail.jp

An experimental investigation of natural freezing and biopolymers for permeability modification to reduce the volume of dense non-aqueous phase liquids in groundwater

Thesis (M.S.) University of Alaska Fairbanks, 2004Dense Non-Aqueous Phase Liquid (DNAPL) contamination is one of the major environmental concerns today. DNAPL can remain in significant quantities as residual contaminants in the low permeability zones even after the bulk phase has been removed. As the drive fluid sweeps through the aquifer it follows the path of least resistance, which is the high permeability zone. Thus the contaminants trapped in the low permeability zones remain as residuals and serve as a source for prolonged contamination. Conventional remediation techniques are ill-equipped to deal with the heterogeneities of the aquifers. Various techniques to enhance the efficiency of the conventional methods are tried without significant success. Reducing the temperature of soil formations can modify aquifer flow paths. The natural freezing of soils in winter may be used effectively to modify the flow paths. In summer, permeability modification can be accomplished by emplacement of microbial polymer gels. In this thesis, we have investigated using a laboratory scale one dimensional column experiment, a novel technique to reduce the volume of residual DNAPL using a combination of natural freezing in winter and biopolymer in summer.1. Introduction -- 2. Literature review -- 2.1. Groundwater contamination -- 2.2. Enhanced remediation techniques -- 2.3. Permeability modification for remediation techniques -- 3. Materials & methods -- 4. Results & discussions -- 4.3. Permeability modification by curdlan polymer gel -- 4.4. Decrease in residual DNAPL volume -- 5. Conclusions & future work -- 6. References

Challenges in the use of quantum computing hardware-efficient Ansatze in electronic structure theory

Advances in quantum computation for electronic structure, and particularly heuristic quantum algorithms, create an ongoing need to characterize the performance and limitations of these methods. Here we discuss some potential pitfalls connected with the use of hardware-efficient Ansatze in variational quantum simulations of electronic structure. We illustrate that hardware-efficient Ansatze may break Hamiltonian symmetries and yield non-differentiable potential energy curves, in addition to the well-known difficulty of optimizing variational parameters. We discuss the interplay between these limitations by carrying out a comparative analysis of hardware-efficient Ansatze versus unitary coupled cluster and full configuration interaction, and of second- and first-quantization strategies to encode fermionic degrees of freedom to qubits. Our analysis should be useful in understanding potential limitations and in identifying possible areas of improvement in hardware-efficient Ansatze.Comment: 16 pages, 9 figures, supplemental information included as an ancillary fil