717 research outputs found
Atlantic cod aquaculture: Boom, bust, and rebirth?
The commercialization of a new species through aquaculture is much more complex than the mastery of the production process, or closing the loop, as it is sometimes referred to. Commercial aquaculture is a layer within the global seafood industry, much as wild capture is; however, it places human control at a much earlier phase in the life cycle of the harvested product. As an important species on both sides of the Atlantic, the commercialization efforts for the culture of Atlantic cod are described for four locations, Norway, United Kingdom, New England, and Atlantic Canada that highlight many similar technical challenges and the progress made from the late 1980s through 2012. We also describe some of the marketing challenges faced and how they differ. Technically, the species has been commercialized. Hatcheries and farms in all four countries were successfully established. However, there are clear differences in access to capital for research and industrial expansion from both the private and public sector, social acceptance of farmed fish, as well as the impacts on sales when marketing farmed cod in the context of a global seafood supply. Lower cost species substitution, from either the farmed or wild catch, is also a factor that can have a significant impact on long-term successful commercialization.publishedVersio
Asymmetric dearomatization/cyclization enables access to polycyclic chemotypes
Enantioenriched, polycyclic compounds were obtained from a simple acylphloroglucinol scaffold. Highly enantioselective dearomatization was accomplished using a Trost ligand-palladium(0) complex. A computational DFT model was developed to rationalize observed enantioselectivities and revealed a key reactant-ligand hydrogen bonding interaction. Dearomatized products were used in visible light-mediated photocycloadditions and oxidative free radical cyclizations to obtain novel polycyclic chemotypes including tricyclo[4.3.1.01,4]decan-10-ones, bicyclo[3.2.1]octan-8-ones and highly-substituted cycloheptanones.R24 GM111625 - NIGMS NIH HH
Case Studies In Turbomachinery Operation And Maintenance Using Condition Monitoring.
LecturePg. 101-112With exceedingly high downtime costs and the need for efficient operation of turbo machinery, integrated condition monitoring, wherein a number of health parameters are analyzed, is becoming increasingly popular in process plants and in utilities. Most operational problems can be diagnosed by developing a correlation among several key operating parameters. A wide range of condition monitoring approaches are available and this paper shows how several approaches can be used in conjunction with one another to solve operational problems. Several case studies pertaining to gas and steam turbines and compressors are presented. A matrix of condition monitoring techniques is provided and case studies are presented. Finally, future trends in the area of condition monitoring are presented
Lunar apatite with terrestrial volatile abundances
The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO_2-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained ~1,600 parts per million H_2O and ~3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought
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Chemical Evidence for Cell Wall Lignification and the Evolution of Tracheids in Early Devonian Plants
Anatomically preserved land plant fossils from the Lower Devonian Rhynie Chert contain conducting tissues with cells that range from dark-colored, elongated cells without secondary wall thickenings to tracheids similar to those of extant tracheophytes. A suite of tissue-specific microanalytical techniques was used to assess lignification in fossils of Aglaophyton, Rhynia, and Asteroxylon. Isotope ratio mass spectrometry provides millimeter-scale resolution of carbon isotopic abundances, whereas soft X-ray carbon (1s) spectromicroscopy provides micrometer-scale resolution of the preservation of organic molecular functionality. The isotopic and organic chemistry of Rhynie Chert plants indicates that the earliest vascular thickenings were probably unlignified and that cell wall lignification may have first appeared in the outer cortex. Only in more derived plants, it seems, was lignin deposited in conducting cells to produce the true tracheids seen today in vascular plants.Organismic and Evolutionary Biolog
HST Imaging of the Host Galaxies of High Redshift Radio-Loud Quasars
We present rest-frame UV and Ly-alpha images of spatially-resolved structures
around five high-redshift radio-loud quasars obtained with the WFPC2 camera on
the Hubble Space Telescope. We find that all five quasars are extended and this
"fuzz" contains ~5-40% of the total continuum flux and 15-65% of the Ly-alpha
flux within a radius of about 1.5 arcsec. The rest-frame UV luminosities of the
hosts are log lambda P_lambda = 11.9 to 12.5 solar luminosities (assuming no
internal dust extinction), comparable to the luminous radio galaxies at similar
redshifts and a factor 10 higher than both radio-quiet field galaxies at z~2-3
and the most UV-luminous low redshift starburst galaxies. The Ly-alpha
luminosities of the hosts are (in the log) approximately 44.3-44.9 erg/s which
are also similar to the those of luminous high redshift radio galaxies and
considerably larger than the Ly-alpha luminosities of high redshift field
galaxies. To generate the Ly-alpha luminosities of the hosts would require
roughly a few percent of the total observed ionizing luminosity of the quasar.
We find good alignment between the extended Ly-alpha and the radio sources,
strong evidence for jet-cloud interactions in two cases, again resembling radio
galaxies, and what is possibly the most luminous radio-UV synchrotron jet in
one of the hosts at z=2.110.Comment: 36 pages (latex, aas macros), 3 figures (3 gif and 10 postscript
files), accepted for publication in the the Astrophysical Journal Supplement
Serie
Understanding Behavioral Sources of Process Variation Following Enterprise System Deployment
This paper extends the current understanding of the time-sensitivity of intent and usage following large-scale IT implementation. Our study focuses on perceived system misfit with organizational processes in tandem with the availability of system circumvention opportunities. Case study comparisons and controlled experiments are used to support the theoretical unpacking of organizational and technical contingencies and their relationship to shifts in user intentions and variation in work-processing tactics over time. Findings suggest that managers and users may retain strong intentions to circumvent systems in the presence of perceived task-technology misfit. The perceived ease with which this circumvention is attainable factors significantly into the timeframe within which it is attempted, and subsequently impacts the onset of deviation from prescribed practice and anticipated dynamics
The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery
ACKNOWLEDGEMENTS Review and editing: S.R. Brown, Professor of Surgery, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK. Email [email protected]. Patient summary: R.G. Arnott, Retired Professor, Patient Liaison Group, Association of Coloproctology of Great Britain and Ireland, Royal College of Surgeons of England, London, UK. Email [email protected]. Delphi review: C.P. Macklin. BMedSci BM BS FRCS DM, Consultant Colorectal Surgeon, Mid Yorkshire Hospitals, UK. Email [email protected] reviewedPublisher PD
Antecedent Treatment with Different Antibiotic Agents as a Risk Factor for Vancomycin-Resistant Enterococcus
We conducted a matched case-control study to compare the effect of antecedent treatment with various antibiotics on subsequent isolation of vancomycin-resistant Enterococcus (VRE); 880 in-patients; 233 VRE cases, and 647 matched controls were included. After being matched for hospital location, calendar time, and duration of hospitalization, the following variables predicted VRE positivity: main admitting diagnosis; a coexisting condition (e.g., diabetes mellitus, organ transplant, or hepatobiliary disease); and infection or colonization with methicillin-resistant Staphylococcus aureus or Clostridium difficile within the past year (independent of vancomycin treatment). After controlling for these variables, we examined the effect of various antibiotics. Intravenous treatment with third-generation cephalosporins, metronidazole, and fluoroquinolones was positively associated with VRE. In our institution, when we adjusted the data for temporo-spatial factors, patient characteristics, and hospital events, treatment with third-generation cephalosporins, metronidazole, and fluoroquinolones was identified as a risk factor for VRE. Vancomycin was not a risk factor for isolation of VRE
Smoking cessation in severe mental ill health : what works? an updated systematic review and meta-analysis
BACKGROUND: People with severe mental ill health are more likely to smoke than those in the general population. It is therefore important that effective smoking cessation strategies are used to help people with severe mental ill health to stop smoking. This study aims to assess the effectiveness and cost -effectiveness of smoking cessation and reduction strategies in adults with severe mental ill health in both inpatient and outpatient settings. METHODS: This is an update of a previous systematic review. Electronic databases were searched during September 2016 for randomised controlled trials comparing smoking cessation interventions to each other, usual care, or placebo. Data was extracted on biochemically-verified, self-reported smoking cessation (primary outcome), as well as on smoking reduction, body weight, psychiatric symptom, and adverse events (secondary outcomes). RESULTS: We included 26 trials of pharmacological and/or behavioural interventions. Eight trials comparing bupropion to placebo were pooled showing that bupropion improved quit rates significantly in the medium and long term but not the short term (short term RR = 6.42 95% CI 0.82-50.07; medium term RR = 2.93 95% CI 1.61-5.34; long term RR = 3.04 95% CI 1.10-8.42). Five trials comparing varenicline to placebo showed that that the addition of varenicline improved quit rates significantly in the medium term (RR = 4.13 95% CI 1.36-12.53). The results from five trials of specialised smoking cessation programmes were pooled and showed no evidence of benefit in the medium (RR = 1.32 95% CI 0.85-2.06) or long term (RR = 1.33 95% CI 0.85-2.08). There was insufficient data to allowing pooling for all time points for varenicline and trials of specialist smoking cessation programmes. Trials suggest few adverse events although safety data were not always reported. Only one pilot study reported cost effectiveness data. CONCLUSIONS: Bupropion and varenicline, which have been shown to be effective in the general population, also work for people with severe mental ill health and their use in patients with stable psychiatric conditions. Despite good evidence for the effectiveness of smoking cessation interventions for people with severe mental ill health, the percentage of people with severe mental ill health who smoke remains higher than that for the general population
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