3,066 research outputs found

    Prairie Farms Dairy, Inc.: Economic Impact of a Dairy Cooperative [This report is now at http://purl.umn.edu/180971]

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    This report is now at http://purl.umn.edu/180971Dairy cooperative, fluid milk, processing, distribution, history, economic impact., Livestock Production/Industries,

    Emergent functional behaviour of humic substances perceived as complex labile aggregates of small organic molecules and oligomers

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    The structural organisation of humic substances (HS) has been a central question of earth sciences for several decades. The latest experimental results have led to the recognition of HS as complex mixtures of small molecules and oligomers. We investigate the correlation between the chemical composition of HS, perceived as labile aggregates, and the emergent functions. Computational modelling was used to help to understand the processes and mechanisms on the molecular scale that occur in different fractions of the HS, fulvic acids (FA) and humic acids (HA), as they interact with metal ions and organic pollutants. The importance of non-covalent interactions in the emergent functions of HS is highlighted. H-bonding, hydrophilic/hydrophobic surface areas and pi-stacking interactions play a significant role in aggregation processes as well as in the sorption of environmental pollutants. In a highly hydrophilic system with small molecules (the SRFA-22 model), H-bonding is the main force that drives the aggregation process. However, in a highly aromatic and hydrophobic model with larger molecular fragments (SRHA-6), hydrophobic and p-stacking interactions dominate in the aggregation process. The chemical properties of contaminants significantly affect their mechanisms of sorption by HS. The interaction of a polar pollutant, phenol, with HS occurs through H-bonding, whereas non-polar benzene interacts through hydrophobic and pi-stacking interactions. The non-polar pollutant results in a much stronger sorption by HS and causes an additional structural rearrangement of the aggregates, which make it more stable in the environment

    Continuous Measurement and Stochastic Methods in Quantum Optical Systems

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    This dissertation studies the statistics and modeling of a quantum system probed by a coherent laser field. We focus on an ensemble of qubits dispersively coupled to a traveling wave light field. The first research topic explores the quantum measurement statistics of a quasi-monochromatic laser probe. We identify the shortest timescale that successive measurements approximately commute. Our model predicts that for a probe in the near infrared, noncommuting measurement effects are apparent for subpicosecond times. The second dissertation topic attempts to find an approximation to a conditional master equation, which maps identical product states to identical product states. Through a technique known as projection filtering, we find such a equation for an ensemble of qubits experiencing a diffusive measurement of a collective angular momentum projection, and global rotations. We then test the quality of the approximation through numerical simulations. In the presence of strong randomized rotations, the approximation reproduces the exact expectation values to within 95%. The final topic applies the projection filter to the problem of state reconstruction. We find an initial state estimate based on a single continuous measurement of an identically prepared atomic ensemble. Given the ability to make a continuous collective measurement and simultaneously applying time varying controls, it is possible to find an accurate estimate given based upon a single measurement realization. Here we explore the fundamental limits of this protocol by studying an idealized model for pure qubits, which is limited only by measurement backaction. Using the exact dynamics to produce simulated measurements, we then numerically search for a maximum likelihood estimate based on the approximate expression. Our estimation technique nearly achieves an average fidelity bound set by an optimum POVM.Comment: PhD Dissertatio

    Single Shot Quantum State Estimation via a Continuous Measurement in the Strong Backaction Regime

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    We study quantum tomography based on a stochastic continuous-time measurement record obtained from a probe field collectively interacting with an ensemble of identically prepared systems. In comparison to previous studies, we consider here the case in which the measurement-induced backaction has a nonnegligible effect on the dynamical evolution of the ensemble. We formulate a maximum likelihood estimate for the initial quantum state given only a single instance of the continuous diffusive measurement record. We apply our estimator to the simplest problem -- state tomography of a single pure qubit, which, during the course of the measurement, is also subjected to dynamical control. We identify a regime where the many-body system is well approximated at all times by a separable pure spin coherent state, whose Bloch vector undergoes a conditional stochastic evolution. We simulate the results of our estimator and show that we can achieve close to the upper bound of fidelity set by the optimal POVM. This estimate is compared to, and significantly outperforms, an equivalent estimator that ignores measurement backaction.Comment: 10 pages, 5 epic figure

    Development of techniques for the restoration of temperate biogenic reefs

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    Biogenic reefs are of ecological importance due to the high levels of biodiversity they support and the valuable ecosystem services they provide. These reefs have limited distributions, are vulnerable to anthropogenic damage and their natural recovery has been estimated to be very slow. This project therefore aimed to develop restoration techniques that accelerate the natural recovery of biogenic reefs created by Serpula vermicularis (L.) (Polychaeta: Serpulidae), Limaria hians (G.) (Mollusca: Limacea) and Modiolus modiolus (L.) (Mollusca: Bivalvia) all three of which are of conservation importance in the North-East Atlantic. This aim was achieved through trials of novel restoration techniques to assess their potential for future larger scale restoration attempts. The addition of hard substrate proved a reliable restoration technique for all three of the study species. In particular, substrates providing structural complexity supported the highest abundance of recruits. Other restoration techniques, including stock enhancement and substrate stabilisation were found to be less effective. The timing for the deployment for these substrates was also shown to effect the abundance of S. vermicularis recruits, with materials deployed in July having 61 % more colonists than materials deployed in November. The location of deployed substrates within the Loch Creran, Scotland were also shown to create differences in S. vermicularis recruitment, with sites away from existing reefs having 72 % more recruits than sites within existing reef areas. Differences in the effectiveness of restoration treatments between sites was also observed for M. modiolus, with Loch Creran and Scapa Flow sites having on average 1.15 and 1.03 juveniles per restoration unit respectively, compared to 70 juveniles per unit at the site north of Lleyn Peninsula, Wales. The project also highlights taxonomic problems with the identification of juvenile M. modiolus, before providing a robust method validated using DNA barcoding techniques to differentiation M. modiolus from other juvenile bivalves. Whilst the project suggests that the successful restoration of these three biogenic reef-forming species is achievable, it also highlights that the first step in any restoration project must be the removal of pressures on that habitat. The substantial decline in the L. hians reef off Port Appin, Scotland from 40.5 hectares in 2006 to just 2.73 hectares in 2015 shows that without this first step any attempted restoration project would not succeed

    Estrogen receptor-? signaling and localization regulates autophagy and unfolded protein response activation in ER+ breast cancer

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    Antiestrogen therapy is commonly used to treat estrogen receptor (ER)+ breast cancers but acquired and de novo resistance limits their overall curative potential. An endoplasmic reticulum stress pathway, the unfolded protein response, and autophagy are both implicated in the development of antiestrogen therapy resistance in estrogen receptor-? (ER) positive breast cancer. Thus, we recently investigated how ER? can regulate autophagy and the unfolded protein response (Cook et al., FASEBJ, 2014). We showed that inhibiting ER? signaling stimulates autophagosome formation and flux. Moreover, we showed that ER? knockdown inhibited the unfolded protein response (UPR) signaling components. Here we support and extend this recent report showing additional data on ER? localization and provide a schematic of the overall signaling implicated by our results. Differential activation of UPR and autophagy highlight the pivotal role of ER? in regulating pro-survival signaling in breast cancer through UPR and autophagy. Furthermore, these data suggest new approaches to successful targeting ER? and preventing the regulation of key pro-survival signaling that confers resistance to endocrine therapies.&nbsp

    University Based Multidisciplinary Organizations - Promises and Challenges

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    The Diagnostic Instrumentation and Analysis Laboratory (DIAL) at Mississippi State University is a multidisciplinary research organization engaged in developing and applying advanced computer-controlled, optical and laser-based diagnostic instrumentation systems for the characterization of high temperature gas streams. Part of the mission of DIAL is the on-site application of the diagnostic systems to large-scale facilities. The laboratory has approximately 40 professional and support personnel. Twelve faculty members are associated with the laboratory and, because of the multidisciplinary nature of the research program, their disciplines cross college as well as departmental boundaries. This provides for unique graduate research opportunities. Moreover, the laboratory employees 12 full-time research scientists and engineers in addition to a number of technicians and graduate students. The overall program of the laboratory and the rationale for such mission-oriented organizations are presented. In addition, it is pointed out that an organization of this type presents particular administrative problems in universities. While the path from instructor to university president is well laid out in the tenure track system, the administrative path in which the cross-disciplinary researchers find themselves is often unexplored by them or university administrators. Though there are clearly numerous advantages to this kind of organization, there are also disadvantages. Most of these advantages and disadvantages apply to many cross-disciplinary research groups to varying degrees, and these are also discussed in a general way. Recommendations for interfacing cross disciplinary research groups are also given

    U.S. Firm outsourcing/offshoring practices and plans: an update

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    A study of U.S. firm outsourcing and offshoring practices and future plans regarding supply chain activities provides an update for supply chain managers. Specifically, the reported information provides supply chain managers of manufacturing/ merchandising firms with a competitive benchmark; facilitates third party logistics manager strategic planning efforts and provides an input to U.S. transportation planners who determine future transport and infrastructure requirements. The study reports the responses of 151 Chief Purchasing Officers from U.S. firms. Firms are benefiting from outsourcing logistics and production activities and over one-third of the firms plan to increase outsourcing spend. In addition, 60 percent of firms outsource offshore, and of these firms, 41 percent will increase their offshore spending, some by more than 50 percent

    \u3csup\u3e13\u3c/sup\u3eC Nuclear magnetic resonance and electron paramagnetic spectroscopic comparison of hydrophobic acid, transphilic acid, and reverse osmosis May 2012 isolates of organic matter from the Suwannee River

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    © 2015 Mary Ann Liebert, Inc. Dissolved organic matter (DOM) is found in most natural waters at concentrations low enough to make DOM isolation methodologies critical to full analytical characterization and preservation. During the last few decades, two major protocols have been developed for the extraction of DOM isolates from natural waters. These methods utilize XAD resins and reverse osmosis (RO). In this work, the hydrophobic acid (May 2012 HPOA) and transphilic acid (May 2012 TPIA) isolates from XAD-8 and XAD-4 resins, respectively, were compared with the RO (May 2012 RO) natural organic matter isolate of the Suwannee River water using 13C nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies. 13C NMR analysis showed that the May 2012 RO isolate could be viewed as a hybrid of the more hydrophobic May 2012 HPOA isolate and more hydrophilic May 2012 TPIA isolate. The May 2012 HPOA isolate is shown to be higher in alkyl and aromatic moieties, while the May 2012 TPIA isolate is higher in O-alkyl moieties. EPR analysis revealed that the May 2012 TPIA and, in particular, May 2012 HPOA isolates had higher radical concentrations than the May 2012 RO isolate. It is postulated that some of the radical concentrations came from the use of base during the isolation procedures, especially in the XAD method
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