991 resultados para Co-thought gestures


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Regulatory action to protect California’s coastal water quality from degradation by copper from recreational boats’ antifouling paints interacts with efforts to prevent transport of invasive, hull-fouling species. A copper regulatory program is in place for a major yacht basin in northern San Diego Bay and in process for other major, California boat basins. “Companion” fouling control strategies are used with copper-based antifouling paints, as some invasive species have developed resistance to the copper biocide. Such strategies are critical for boats with less toxic or nontoxic hull coatings. Boat traffic along over 3,000 miles of coastline in California and Baja California increases invasive species transport risks. For example, 80% of boats in Baja California marinas are from the United States, especially California. Policy makers, boating businesses and boat owners need information on costs and supply-side capacity for effective fouling control measures to co-manage water quality and invasive species concerns. (PDF contains 3 pages)

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The anionic tripod ligand NaLoMe (L_(oMe) - = [(η^5-C_5H_5)Co{P(O)(OCH_3)_2}_3]^-) reacts with RuO_4 in a biphasic reaction mixture of 1% H_2SO_4 and CCI_4 to afford [(L_(oMe) (HO)Ru^(IV) (µ-O)_2Ru ^(IV)(OH)(L_(oMe)] (1), which is treated with aqueous CF_3S0_3H to generate [(L_(oMe)(H_2O)Ru^(IV) (µ-O)_2R^(IV) (OH_2)(L_(oMe)][CF_3SO_3]_2 ([H_21][CF_3SO_3]_2). Addition of iodosobenzene to an acetonitrile solution of this salt yields [(L_(oMe)(O)Ru^v(µ-0)2Ru^v-(O)(_(LoMe)] (2). The dimer 1 can be reduced chemically or electrochemically to the Ru^(III)- Ru^(III) dimers [(L_(oMe)(H_20)Ru^(III) (µ-OH)_2Ru^(III) (OH_2)(L_(oMe)) ]^2+ and [(L_(oMe)) ^(III) (µ-0Hh(µ-0H2)Ru^(III) (L_(oMe)]^2+ which interconvert in aqueous media. Two electron processes dominate both the bulk chemistry and the electrochemistry of 1. Among these processes are the quasi-reversible Ru^(IV) - Ru^(IV)/Ru^(III)- Ru^(III) and Ru^(III)- Ru^(III)/ Ru^(II)- Ru^(II) reductions and a largely irreversible Ru^(V) - Ru^(V)/ Ru^(IV) - Ru^(IV)/oxidation. The dioxo dimer 2 oxidizes alcohols and aldehydes in organic media to afford 1 and the corresponding aldehydes and acids. Analogously, the Ru^(V) - Ru^(V)/ Ru^(IV)- Ru^(IV) redox wave mediates the electrooxidation of alcohols and aldehydes in aqueous buffer. In this system, substrates can be oxidized completely to CO_2. The kinetic behavior of these oxidations was examined by UV-vis and chronoamperometry, respectively, and the chemistry is typical of metal-oxo complexes, indicating that electronic coupling between two metal centers does not dramatically affect the metal-oxo chemistry. Dimer [H_21]^(2+) also reacts with alcohols, aldehydes, and triphenylphosphine in CH_3CN to afford Ru^(III)- Ru^(III) products including [(L_(oMe))CH_3CN) Ru^(III) (µ-OH)_2 Ru^(III) (NCCH_3)( L_(oMe))][CF_3SO_3]2 (characterized by X-ray crystallography) and the corresponding organic products. Reaction of 1 with formaldehyde in aqueous buffer quantitatively affords the triply bridged dimer [(L_(oMe)Ru^(III) (µ-OH)2- (µ-HCOO) Ru^(III) (L_(oMe)][CF_3SO_3] (characterized by X-ray crystallography). This reaction evidently proceeds by two parallel inner-sphere pathways, one of which is autocatalytic. Neither pathway exhibits a primary isotope effect suggesting the rate determining process could be the formation of an intermediate, perhaps a Ru^(IV) - Ru^(IV) formate adduct. The Ru^(III)- Ru^(III)formate adduct is easily oxidized to the Ru^(IV) - Ru^(IV) analog [(L_(oMe)Ru^(IV)(µ-OH)_2-(µ-HCOO) Ru^(IV) (L_(oMe)][CF_3SO_3], which, after isolation, reacts slowly with aqueous formaldehyde to generate free formate and the Ru^(III)- Ru^(III) formate adduct. These dimers function as catalysts for the electrooxidation of formaldehyde at low anodic potentials (+0.0 V versus SCE in aqueous buffer, pH 8.5) and enhance the activity of Nafion treated palladium/carbon heterogeneous fuel cell catalysts.

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Within natural resource management, there is increasing criticism of the traditional model of top-down management as a method of governance, as researchers and managers alike have recognized that resources can frequently be better managed when stakeholders are directly involved in management. As a result, in recent years the concept of co-management of natural resources, in which management responsibilities are shared between the government and stakeholders, has become increasingly popular, both in the academic literature and in practice. However, while co-management has significant potential as a successful management tool, the issue of equity in co-management has rarely been addressed. It is necessary to understand the differential impacts on stakeholders of co-management processes and the degree to which diverse stakeholders are represented within co-management. Understanding the interests of various stakeholders can be a way to more effectively address the distributional and social impacts of coastal policies, which can in turn increase compliance with management measures and lead to more sustainable resource management regimes. This research seeks to take a closer look at the concepts of co-management and participation through a number of case studies of marine protected areas (MPAs) in the Caribbean. (PDF contains 4 pages)

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The signal recognition particle (SRP) and its receptor (SR) are universally conserved protein machineries that deliver nascent peptides to their proper destination. The SRP RNA is a universally conserved and essential component of SRP, which serves as the “catalyst” of the protein targeting cycle. The SRP RNA accelerates SRP-SR complex formation at the beginning of the protein targeting reaction, and triggers GTP hydrolysis and SRP-SR complex disassembly at the end. Here we combined biochemical and biophysical approaches to investigate the molecular mechanism of the functions of the SRP RNA. We found that two functional ends in the SRP RNA mediate distinct functions. The tetraloop end facilitates initial assembly of SRP and SR by mediating an electrostatic interaction with the Lys399 receptor, which ensures efficient and accurate substrate targeting. At the later stage of the SRP cycle, the SRP-SR complex relocalizes ~ 100 Angstrom to the 5’,3’-distal end of the RNA, a conformation crucial for GTPase activation and cargo handover. These results, combined with recent structural work, elucidate the functions of the SRP RNA during the protein targeting reaction.

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Current measures of global gene expression analyses, such as correlation and mutual information-based approaches, largely depend on the degree of association between mRNA levels and to a lesser extent on variability. I develop and implement a new approach, called the Ratiometric method, which is based on the coefficient of variation of the expression ratio of two genes, relying more on variation than previous methods. The advantage of such modus operandi is the ability to detect possible gene pair interactions regardless of the degree of expression dispersion across the sample group. Gene pairs with low expression dispersion, i.e., their absolute expressions remain constant across the sample group, are systematically missed by correlation and mutual information analyses. The superiority of the Ratiometric method in finding these gene pair interactions is demonstrated in a data set of RNA-seq B-cell samples from the 1000 Genomes Project Consortium. The Ratiometric method renders a more comprehensive recovery of KEGG pathways and GO-terms.

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The combustion of CS₂ and O₂ in a free burning laminar mixing layer at low pressure was investigated using emission spectroscopy. The temperature fields, CO vibrational distributions, and CO concentrations were measured. The data indicate that vibration ally excited CO was produced in the mixing layer flames, but that there were no vibrational population inversions. In comparison with the CS₂/O₂ premixed flames, the mixing layer flames favored greater production of COS and CO₂. Computer modeling was used to study the mechanisms responsible for the production of COS and CO₂, and to study how the branching chain mechanism responsible for production of CO affects the behavior of the mixing layer flame. The influences of the gas additives, N₂O, COS, and CNBr, were also investigated.

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The influence of composition on the structure and on the electric and magnetic properties of amorphous Pd-Mn-P and Pd-Co-P prepared by rapid quenching techniques were investigated in terms of (1) the 3d band filling of the first transition metal group, (2) the phosphorus concentration effect which acts as an electron donor and (3) the transition metal concentration.

The structure is essentially characterized by a set of polyhedra subunits essentially inverse to the packing of hard spheres in real space. Examination of computer generated distribution functions using Monte Carlo random statistical distribution of these polyhedra entities demonstrated tile reproducibility of the experimentally calculated atomic distribution function. As a result, several possible "structural parameters" are proposed such as: the number of nearest neighbors, the metal-to-metal distance, the degree of short-range order and the affinity between metal-metal and metal-metalloid. It is shown that the degree of disorder increases from Ni to Mn. Similar behavior is observed with increase in the phosphorus concentration.

The magnetic properties of Pd-Co-P alloys show that they are ferromagnetic with a Curie temperature between 272 and 399°K as the cobalt concentration increases from 15 to 50 at.%. Below 20 at.% Co the short-range exchange interactions which produce the ferromagnetism are unable to establish a long-range magnetic order and a peak in the magnetization shows up at the lowest temperature range . The electric resistivity measurements were performed from liquid helium temperatures up to the vicinity of the melting point (900°K). The thermomagnetic analysis was carried out under an applied field of 6.0 kOe. The electrical resistivity of Pd-Co-P shows the coexistence of a Kondo-like minimum with ferromagnetism. The minimum becomes less important as the transition metal concentration increases and the coefficients of ℓn T and T^2 become smaller and strongly temperature dependent. The negative magnetoresistivity is a strong indication of the existence of localized moment.

The temperature coefficient of resistivity which is positive for Pd- Fe-P, Pd-Ni-P, and Pd-Co-P becomes negative for Pd-Mn-P. It is possible to account for the negative temperature dependence by the localized spin fluctuation model and the high density of states at the Fermi energy which becomes maximum between Mn and Cr. The magnetization curves for Pd-Mn-P are typical of those resulting from the interplay of different exchange forces. The established relationship between susceptibility and resistivity confirms the localized spin fluctuation model. The magnetoresistivity of Pd-Mn-P could be interpreted in tenns of a short-range magnetic ordering that could arise from the Rudennan-Kittel type interactions.

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An experimental investigation of low frequency floating potential fluctuations (f ≤ 200 kHz) in a research tokamak plasma using two spatially separated electrostatic probes has been performed. The spectra, correlation length, and the phase velocity of the fluctuations in both the radial and azimuthal direction have been determined. The propagation velocity in the toroidal direction was also measured and was found to be in the direction of electron current flow. The waves traveled azimuthally in the ion diamagnetic drift direction, even after the usual E x B rotation was taken into account. The electron density fluctuations associated with these oscillations were large, δn/n ≃ 0.35 - 0.50.

The spectra were found to have regularly spaced peaks which seemed to be related to specific azimuthal modes (m =1,2,3,...,etc. ) A parametric study was made to determine what effect plasma parameters had on these peaks. During periods of high electron density in the first 2 msec of the plasma lifetime, strong sawtooth type oscillations were observed. These oscillations typically had frequencies of approximately 10 kHz and were also present when large amounts of neutral gas were added during the discharge by a process called "gas puffing."

The results are compared with experimental observations made on other plasma devices with electric and magnetic probes and with microwave and CO2 laser scattering techniques. (The scattering measurements are complimentary to the probe measurements since, in the former case, the wavelength is fixed by the scattering angle, but the oscillations could not be spatially localized.) The oscillations in the Caltech torus were probably related to a drift-tearing type instability which is thought to play a major role in the anomalous particle and energy flux observed in tokamaks. Comparisons are made between current theory and the experimental results. However, the theory for the observed oscillations is still in a rudimentary stage of development, and it is hoped that the present investigation will stimulate future analytical work.

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Research laboratories in the Burrishoole catchment have been the focus of salmonid research since 1955. One aspect of the research has been to monitor the number of salmon and sea trout migrating to sea as smolts and returning to the catchment as adults. In the early 1990s it became clear that the smolt output from the catchment had declined over the previous two decades. At about the same time the presence of fine particles of peat silt in the hatchery became increasingly apparent and led to a higher incidence of mortality of young fry. These observations and management difficulties led to a study of silt transport in the surface waters of the catchment, which is described in this article. The authors describe geology, soils, climate and hydrology of Burrishoole before examining the sediment deposition in Lough Feeagh.

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In freshwater environments of modest size and without notable ecological structure, there is usually present only one diaptomid species. When two or more diaptomid species are present in the same habitat, generally their body dimensions are distinctly different. There are only four examples of co-existence of Arctodiaptomus bacillifer (Koelb.) and Acanthodiaptomus denticornis (Wierz.) situated at higher altitudes alpine lakes. The article discusses the results of sampling in the summer of 1953 and the problem of the co-existence of Arctodiaptomus bacillifer, Acanthodiaptomus denticornis and Heterocope saliens.

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O presente trabalho buscou avaliar o processo de co-pirólise de resíduos de polipropileno com gasóleo, variando a temperatura e a quantidade de polipropileno no meio reacional. A co-pirólise é uma rota promissora, uma vez que minimiza o impacto ambiental causado pela disposição do plástico de maneira inadequada, evita seu acúmulo em lixões e permite um melhor aproveitamento de um recurso natural não-renovável, o petróleo, matéria-prima importante para a geração de energia e obtenção de produtos químicos. As amostras de polipropileno e gasóleo foram submetidas à co-pirólise térmica em atmosfera inerte, em sistema de leito fixo, sob fluxo constante de nitrogênio, variando a temperatura de 400C a 500C e a quantidade de PP no meio reacional de 0,1 a 1,0 g. A influência do gasóleo no meio foi avaliada pelos testes na ausência de PP. Os líquidos pirolíticos obtidos foram caracterizados por cromatografia gasosa modificada, com o objetivo de avaliar a geração de frações na faixa da destilação do diesel. De uma maneira geral, pôde-se observar que o aumento da quantidade de PP no meio reacional favorece a redução do rendimento de líquido pirolítico e o aumento da quantidade de sólido gerado, efeito inverso ao do aumento da temperatura. Com relação ao rendimento geral de produtos na faixa de destilação do diesel na co-pirólise, a adição de PP ao meio não interfere muito no resultado. Já o aumento de temperatura favorece o aumento do rendimento de produtos nessa faixa de destilação. Os resultados obtidos comprovam o potencial da co-pirólise como método de reciclagem química de artefatos de polipropileno pós-consumo

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Co-management is typically known to be a resource management system that shares managerial responsibility between the state and other stakeholders of a resource. In the case of Lake Victoria, one would expect the state to be represented by the fisheries departments of Kenya, Uganda and Tanzania, while stakeholder groups may comprise fishing communities, fish processing factories and municipalities. Taking that into account, the survey's objectives were defined as: (a) To identify the difficulties and impracticalities inherent in implementing state-based regulations via a "top-down" management strategy. (b) To assess the prevalence of community-based institutions that either seek to regulate the fishery or have the potential to be used to regulate it. (c) To identify ways in which community-based regulatory and monitory systems may be established, and how these will fare over time. (d) To identify roles for national Fisheries Departments, industrial fish processors and other stakeholders. (e) To develop well-founded policy suggestions for the establishment of a co-management framework to manage the fisheries of Lake Victoria.

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In this brief introduction, we set out to provide an overview of the Lake Victoria Fisheries Research Project (LVFRP) and, more specifically, its socio-economic program, and to define the place of the Co-management Survey within the activities of the LVFRP as a whole.

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In this book section, the theoretical background to the methodology is outlined, questionnaire development described, sample selection outlined and biases and shortcomings to the survey noted.