46 research outputs found
Mass Dependent Loss of Resolution in Radially Inhomogeneous ExB Ion Traps
ExB ion traps, such as Fourier transform Ion Cyclotron Resonance mass spectrometers (FY:ICR), mass analyze sample ions based on differences in their cyclotron frequencies in a homogeneous magnetic field. The high resolution mass measurements of FT-ICR are based on the relationship between the frequency of the cyclotron orbit and the mass-to-charge (m/q) ratio of an ion. Both the orbit and the frequency/mass relationship result from the radial forces on the ion. Ions trapped by inhomogeneous electric fields experience different magnitudes of the radial electric fields at different positions resulting in a positionally dependent frequency. Such differences in orbital frequencies for ions of a single m/q ratio result in line broadening and loss of resolution
Restoring Pre-Industrial CO\u3csub\u3e2\u3c/sub\u3e Levels While Achieving Sustainable Development Goals
© 2020 by the authors. Unless humanity achieves United Nations Sustainable Development Goals (SDGs) by 2030 and restores the relatively stable climate of pre-industrial CO2 levels (as early as 2140), species extinctions, starvation, drought/floods, and violence will exacerbate mass migrations. This paper presents conceptual designs and techno-economic analyses to calculate sustainable limits for growing high-protein seafood and macroalgae-for-biofuel. We review the availability of wet solid waste and outline the mass balance of carbon and plant nutrients passing through a hydrothermal liquefaction process. The paper reviews the availability of dry solid waste and dry biomass for bioenergy with CO2 capture and storage (BECCS) while generating Allam Cycle electricity. Sufficient wet-waste biomass supports quickly building hydrothermal liquefaction facilities. Macroalgae-for-biofuel technology can be developed and straightforwardly implemented on SDG-achieving high protein seafood infrastructure. The analyses indicate a potential for (1) 0.5 billion tonnes/yr of seafood; (2) 20 million barrels/day of biofuel from solid waste; (3) more biocrude oil from macroalgae than current fossil oil; and (4) sequestration of 28 to 38 billion tonnes/yr of bio-CO2. Carbon dioxide removal (CDR) costs are between 25–33% of those for BECCS with pre-2019 technology or the projected cost of air-capture CDR
Proteomics and in silico approaches to extend understanding of the glutathione transferase superfamily of the tropical liver fluke Fasciola gigantica
Fasciolosis is an important foodborne, zoonotic disease of livestock and humans, with global annual health and economic losses estimated at several billion US$. Fasciola hepatica is the major species in temperate regions, while F. gigantica dominates in the tropics. In the absence of commercially available vaccines to control fasciolosis, increasing reports of resistance to current chemotherapeutic strategies and the spread of fasciolosis into new areas, new functional genomics approaches are being used to identify potential new drug targets and vaccine candidates. The glutathione transferase (GST) superfamily is both a candidate drug and vaccine target. This study reports the identification of a putatively novel Sigma class GST, present in a water-soluble cytosol extract from the tropical liver fluke F. gigantica. The GST was cloned and expressed as an enzymically active recombinant protein. This GST shares a greater identity with the human schistosomiasis GST vaccine currently at Phase II clinical trials than previously discovered F. gigantica GSTs, stimulating interest in its immuno-protective properties. In addition, in silico analysis of the GST superfamily of both F. gigantica and F. hepatica has revealed an additional Mu class GST, Omega class GSTs, and for the first time, a Zeta class member
Penetration of the Stigma and Style Elicits a Novel Transcriptome in Pollen Tubes, Pointing to Genes Critical for Growth in a Pistil
Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. Using microarray analysis in Arabidopsis, we show that pollen tubes that have grown through stigma and style tissues of a pistil have a distinct gene expression profile and express a substantially larger fraction of the Arabidopsis genome than pollen grains or pollen tubes grown in vitro. Genes involved in signal transduction, transcription, and pollen tube growth are overrepresented in the subset of the Arabidopsis genome that is enriched in pistil-interacted pollen tubes, suggesting the possibility of a regulatory network that orchestrates gene expression as pollen tubes migrate through the pistil. Reverse genetic analysis of genes induced during pollen tube growth identified seven that had not previously been implicated in pollen tube growth. Two genes are required for pollen tube navigation through the pistil, and five genes are required for optimal pollen tube elongation in vitro. Our studies form the foundation for functional genomic analysis of the interactions between the pollen tube and the pistil, which is an excellent system for elucidation of novel modes of cell–cell interaction
Reduced microsatellite heterozygosity does not affect natal dispersal in three contrasting roe deer populations
Although theoretical studies have predicted a link between individual multilocus heterozygosity and dispersal, few empirical studies have investigated the effect of individual heterozygosity on dispersal propensity or distance. We investigated this link using measures of heterozygosity at 12 putatively neutral microsatellite markers and natal dispersal behaviour in three contrasting populations of European roe deer (Capreolus capreolus), a species displaying pre-saturation condition-dependent natal dispersal. We found no effect of individual heterozygosity on either dispersal propensity or dispersal distance. Average heterozygosity was similar across the three studied populations, but dispersal propensity and distance differed markedly among them. In Aurignac, dispersal propensity and distance were positively related to individual body mass, whereas there was no detectable effect of body mass on dispersal behaviour in Chiz, and Trois Fontaines. We suggest that we should expect both dispersal propensity and distance to be greater when heterozygosity is lower only in those species where dispersal behaviour is driven by density-dependent competition for resources
Oversight on the borderline: Quality improvement and pragmatic research
Pragmatic research that compares interventions to improve the organization and delivery of health care may overlap, in both goals and methods, with quality improvement (QI) activities. When activities have attributes of both research and QI, confusion often arises about what ethical oversight is, or should be, required. For routine QI, in which the delivery of health care is modified in minor ways that create only minimal risks, oversight by local clinical or administrative leaders utilizing institutional policies may be sufficient. However, additional consideration should be given to activities that go beyond routine, local QI to first determine whether such non-routine activities constitute research or QI and, in either case, to ensure that independent oversight will occur. This should promote rigor, transparency, and protection of patients’ and clinicians’ rights, well-being, and privacy in all such activities. Specifically, we recommend: 1. Health care organizations should have systematic policies and processes for designating activities as routine QI, non-routine QI, or QI research, and determining what oversight each will receive. 2. Health care organizations should have formal and explicit oversight processes for non-routine QI activities that may include input from institutional QI experts, health services researchers, administrators, clinicians, patient representatives, and those experienced in the ethics review of health care activities. 3. QI research requires review by an IRB; for such review to be effective, IRBs should develop particular expertise in assessing QI research. 4. Stakeholders should be included in the review of non-routine QI and QI-related research proposals. Only by doing so will we optimally leverage both pragmatic research on health care delivery and local implementation through QI as complementary activities for improving health
Tunable catalysis by reversible switching between Ru(III) single sites and Ru0 clusters in solid micelles
International audienceTraditionally, catalytic active sites are robust; they do not change after a reaction. We show here that the Ru(III) active sites in a solid micellar Ru(III)@MCM catalyst can be controllably switched to Ru0 nanoclusters and vice versa by a mild treatment. The Ru(III) single-sites selectively catalyze the hydrogenation of functional groups such as carbonyl, and double and triple bonds in aromatic compounds via heterolytic H2 activation. The Ru0 nanoclusters in contrast are very active for hydrogenating aromatic rings. Ru0 nanoclusters are reversibly formed from the Ru(III) sites via hydrolysis and reduction as shown by XAS, HRTEM, CO adsorption, and DFT calculations.The reported strategy offers reversible switching between oxidized and metallic states of Ru to perform different chemical transformations, achieving on-demand active sites
Oversight on the borderline: Quality improvement and pragmatic research
Pragmatic research that compares interventions to improve the organization and delivery of health care may overlap, in both goals and methods, with quality improvement activities. When activities have attributes of both research and quality improvement, confusion often arises about what ethical oversight is, or should be, required. For routine quality improvement, in which the delivery of health care is modified in minor ways that create only minimal risks, oversight by local clinical or administrative leaders utilizing institutional policies may be sufficient. However, additional consideration should be given to activities that go beyond routine, local quality improvement to first determine whether such non-routine activities constitute research or quality improvement and, in either case, to ensure that independent oversight will occur. This should promote rigor, transparency, and protection of patients' and clinicians' rights, well-being, and privacy in all such activities. Specifically, we recommend that (1) health care organizations should have systematic policies and processes for designating activities as routine quality improvement, non-routine quality improvement, or quality improvement research and determining what oversight each will receive. (2) Health care organizations should have formal and explicit oversight processes for non-routine quality improvement activities that may include input from institutional quality improvement experts, health services researchers, administrators, clinicians, patient representatives, and those experienced in the ethics review of health care activities. (3) Quality improvement research requires review by an institutional review board; for such review to be effective, institutional review boards should develop particular expertise in assessing quality improvement research. (4) Stakeholders should be included in the review of non-routine quality improvement and quality improvement-related research proposals. Only by doing so will we optimally leverage both pragmatic research on health care delivery and local implementation through quality improvement as complementary activities for improving health