3,438 research outputs found
Organic sulfur: a spatially variable and understudied component of marine organic matter
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Longnecker, K., Oswald, L., Soule, M. C. K., Cutter, G. A., & Kujawinski, E. B. Organic sulfur: a spatially variable and understudied component of marine organic matter. Limnology and Oceanography Letters, (2020), doi:10.1002/lol2.10149.Sulfur (S) is a major heteroatom in organic matter. This project evaluated spatial variability in the concentration and molecular‐level composition of organic sulfur along gradients of depth and latitude. We measured the concentration of total organic sulfur (TOS) directly from whole seawater. Our data reveal high variability in organic sulfur, relative to established variability in total organic carbon or nitrogen. The deep ocean contained significant amounts of organic sulfur, and the concentration of TOS in North Atlantic Deep Water (NADW) decreased with increasing age while total organic carbon remained stable. Analysis of dissolved organic matter extracts by ultrahigh resolution mass spectrometry revealed that 6% of elemental formulas contained sulfur. The sulfur‐containing compounds were structurally diverse, and showed higher numbers of sulfur‐containing elemental formulas as NADW moved southward. These measurements of organic sulfur in seawater provide the foundation needed to define the factors controlling organic sulfur in the global ocean.We thank Catherine Carmichael, Winifred Johnson, and Gretchen Swarr for assistance with sample collection and processing, and Joe Jennings for the analysis of inorganic nutrients. The help of the captain and crew of the R/V Knorr and the other cruise participants during the “DeepDOM” cruise is appreciated. Two anonymous reviewers and Patricia Soranno provided thorough comments that greatly improved the manuscript. The ultrahigh resolution mass spectrometry samples were analyzed at the WHOI FT‐MS Users' Facility that is funded by the National Science Foundation (grant OCE‐0619608) and the Gordon and Betty Moore Foundation (GMBF1214). This project was funded by NSF grants OCE‐1154320 (to EBK and KL), the W.M. Marquet Award (to KL), and OCE‐1435708 (to GAC). The authors declare no conflicts of interest
Multipole Expansion for Relativistic Coulomb Excitation
We derive a general expression for the multipole expansion of the
electro-magnetic interaction in relativistic heavy-ion collisions, which can be
employed in higher-order dynamical calculations of Coulomb excitation. The
interaction has diagonal as well as off-diagonal multipole components,
associated with the intrinsic and relative coordinates of projectile and
target. A simple truncation in the off-diagonal components gives excellent
results in first-order perturbation theory for distant collisions and for beam
energies up to 200 MeV/nucleon.Comment: 3 figures, Accepted for publication in Phys. Rev.
Single crystal MgB2 with anisotropic superconducting properties
The discovery of superconductor in magnesium diboride MgB2 with high Tc (39
K) has raised some challenging issues; whether this new superconductor
resembles a high temperature cuprate superconductor(HTS) or a low temperature
metallic superconductor; which superconducting mechanism, a phonon- mediated
BCS or a hole superconducting mechanism or other new exotic mechanism may
account for this superconductivity; and how about its future for applications.
In order to clarify the above questions, experiments using the single crystal
sample are urgently required. Here we have first succeeded in obtaining the
single crystal of this new MgB2 superconductivity, and performed its electrical
resistance and magnetization measurements. Their experiments show that the
electronic and magnetic properties depend on the crystallographic direction.
Our results indicate that the single crystal MgB2 superconductor shows
anisotropic superconducting properties and thus can provide scientific basis
for the research of its superconducting mechanism and its applications.Comment: 7 pages pdf fil
Post-market monitoring: legal framework in Brazil and first results
Brazil is presently (2010) the second largest producer of Genetically Modified (GM) crops. The legal framework to support both research activities and the commercial release of Genetically Modified Organisms (GMOs) is, however, very recent, as the Biosafety Law dates back from 2005. After the indispensable risk analysis, done by National Technical Committee for Biosafety (CTNBio), a GM plant can be approved for commercial release. Nevertheless, as stated in the Normative Resolution nr. 5 (NR-5), 2008, the post-market monitoring is mandatory. However, the first GM crop in Brazil, the herbicide tolerant soybean, was harvested in 2005. The CTNBio asked, then, for a monitoring plan and the applicant designed a complex study focused on case-specific monitoring. After four years the detailed field studies proved that no harm derived from this crop. The costs, nevertheless, were enormous. In May 2010, 21 GM plants were already approved for commercial release in Brazil, corresponding to different events in soybean (6), cotton (8) and maize (9). Single and stacked events tolerant to herbicides or insect-resistant are presently been planted for all three crops. If, for each single event and for the stacks, a laborious post market monitoring plan were to be executed, the total costs would be unbearably high. The applicant, i.e. the seed company in the case of the three common crops, is legally responsible for the monitoring in Brazil. It is also responsible to produce an adequate monitoring plan. Since the rules in the Normative Resolution nr. 5 are far from being clear, the applicants either propose an elaborated plan for case-specific monitoring or, conversely, submit a very simple plan, targeting some potential adverse effect that can be more easily evaluated in commercial fields. All data generated must be reported to federal agencies belonging to at least three different ministries. Monitoring is also a responsibility of some federal agencies, as stated in the Biosafety Law, like registration and inspection agencies and other entities, which are responsible for, among other duties, keep updated information in the Biosafety Information Systems (SIB) of institutions and technical responsible individuals that carry out activities and projects related to GMOs and their by products. It is not clearly stated either in the Biosafety Law or in the NR-5 that monitoring should be split in case-specific monitoring and general surveillance, as adopted in Europe. If case-specific monitoring plans are difficult to design, a sensible suggestion for the general surveillance was not yet achieved. Nevertheless, the info-concentrating SIB may be a valuable source for the general surveillance, once it starts to operate. In conclusion, due to the lack of clear information about how to produce an adequate monitoring plan, stakeholders either tend to unnecessarily enlarge the monitoring scope or shorten it to a few objectives. The general surveillance is either not contemplated in the monitoring plans or minimally treated. It is important to keep in mind that the applicants are responsible to produce most of the data, even for the general surveillance, and this can be extremely difficult in a scenario where 20 or more different events are cultivated, frequently in neighboring fields. The EuropaBio approach to general surveillance for cultivation of GM crops (available from Nature Precedings "doi:10.1038/npre.2010.4451.1":http://dx.doi.org/10.1038/npre.2010.4451.1) is difficult to be largely adopted: farmers may be unable to meaningfully answer the questionnaire and the network has a very restricted number of potential participants. CTNBio is aware of these challenges and has already started to adjust the NR-5 to better guide the applicants in their writing of monitoring plans
Post Market Monitoring: Legal Framework in Brazil and First Results(Contribution to the 4th International Workshop on PMEM of Genetically Modified Plants, Quedlinburg)
Brasilien war 2010 der zweitgrößte Anbauer von gentechnisch veränderten Pflanzen. Die rechtliche Basis für die Forschung und kommerzielle Freisetzung von gentechnisch veränderten Organismen geht zurück auf das Jahr 2005. Nach der notwendigen Risikobewertung durch die nationale Technische Kommission für Biologische Sicherheit (CTNBio), kann eine Genehmigung für die kommerzielle Verwertung einer gentechnisch veränderten Pflanze erteilt werden. Allerdings erfordert die Normregel Nr. 5 (NR-5) aus dem Jahre 2008 ein begleitendes Monitoring. Allerdings wurde bereits im Jahre 2005 die erste transgene Pflanze, eine Herbizid-tolerante Sojabohne, in Brasilien angebaut. CTNBio forderte die Ausarbeitung eines Monitoringplanes, dem die Antragsteller mit einem komplexen, fallspezifisch fokussierten Monitoringdesign nachkamen. Nach vier Jahren detaillierter Feldstudien konnten keine Schäden durch den Anbau der transgenen Pflanzen nachgewiesen werden. Der Kostenaufwand war jedoch enorm. Im Juni 2010 waren bereits 23 gentechnisch veränderte Pflanzen mit verschiedenen transgenen Merkmalen für die kommerzielle Nutzung in Brasilien zugelassen: Soja (6 Zulassungen), Baumwolle (8) und Mais (9). Einzelne oder gekoppelte Merkmale für Herbizidtoleranz und Insektenresistenz werden derzeit genutzt. Müsste für jedes einzelne Merkmal oder gekoppelte Merkmale ein eigenständiges Monitoringprogramm durchgeführt werden, wären die Kosten praktisch untragbar. Die Antragsteller sind nach brasilianischem Recht für die Planung und Durchführung des Monitoring verantwortlich. Da die Normregel Nr. 5 keine klaren Vorgaben macht, reichen die Antragsteller entweder sehr detaillierte, fallspezifisch orientierte oder sehr einfache, allgemeine Monitoringpläne ein, die sich auf einfach nachzuweisende, mögliche Effekte im kommerziellen Anbau beziehen. Im Gegensatz zum europäischen Recht unterscheidet weder das brasilianische Biosicherheitsgesetz noch Normregel Nr. 5 ein fallspezifisches Monitoring und eine Allgemeine Beobachtung. Sollte ein fallspezifischer Monitoringplan schwer herzuleiten sein, gibt es keine verbindlichen Vorgaben für eine Allgemeine Beobachtung. Hier kann ein zukünftiges brasilianisches Informationssystem für Biosicherheit wertvolle Unterstützung bieten. Derzeit jedoch ist eine Allgemeine Beobachtung gar nicht oder nur sehr begrenzt in den Monitoringplänen vorgesehen. Es ist zu beachten, dass die Antragsteller in jedem Fall für das Monitoring verantwortlich bleiben. Dies kann jedoch bei zunehmendem Anbau transgener Pflanzen mit verschiedenen (ähnlichen), einzelnen oder gekoppelten Merkmalen auf benachbarten Feldern zu großen Schwierigkeiten bei der Interpretation der einzelnen Monitoringdaten führen. Deshalb ist es notwendig, eine breit angelegte und mit verschiedenen Interessengruppen kommunizierte Monitoringstrategie zu entwickeln. CTNBio ist sich dieser Herausforderungen bewusst und hat in einem ersten Schritt die Normregel Nr. 5 überarbeitet, um den Antragstellern klarere Vorgaben für den Entwurf von Monitoringplänen zu bieten.
Brazil is presently (2010) the second largest producer of genetically modified (GM) crops. The legal framework to support both research activities and the commercial release of Genetically Modified Organisms (GMOs) is, however, very recent, as the Biosafety Law dates back from 2005. After the indispensable risk analysis, done by National Technical Commission for Biosafety (CTNBio), a GM plant can be approved for commercial release. Nevertheless, as stated in the Normative Resolution Nr. 5 (NR-5), of 2008, the post-market monitoring is mandatory. However, the first GM crop in Brazil, the herbicide tolerant soybean, was harvested in 2005. The CTNBio then asked for a monitoring plan and the applicant designed a complex study focused on case-specific monitoring. After four years the detailed field studies proved that no harm derived from this crop. The costs, nevertheless, were enormous. In June 2010, 21 GM plants were already approved for commercial release in Brazil, corresponding to different events in soybean (6), cotton (8) and maize (9). Single and stacked events tolerant to herbicides or insect-resistant are presently been planted. If, for each single event and for the stacks, a laborious post market monitoring plan were to be executed, the total costs would be unbearably high. The applicant is legally and financially responsible for the monitoring in Brazil. It is also responsible to produce an adequate monitoring plan. Since the NR-5 rules are far from being clear, the applicants either proposed an elaborated plan for case-specific monitoring or, conversely, submitted a very simple plan, targeting some potential adverse effect that can be more easily evaluated in commercial fields. It is not clearly stated either in the Biosafety Law or in the NR-5 that monitoring should be split in case-specific monitoring and general surveillance, as adopted in Europe. If case-specific monitoring plans are difficult to design, a sensible suggestion for the general surveillance was not yet achieved. Nevertheless, the info-concentrating Brazilian Biosafety Information System may be a valuable source for the general surveillance, once it starts to operate. The general surveillance is presently either not contemplated in the monitoring plans or only minimally treated. It is important to keep in mind that the applicants are responsible to produce most of the data, even for the general surveillance, and this can be extremely difficult in a scenario where many different events are cultivated, frequently in neighbouring fields. A conceptual framework for post market monitoring must therefore be established following a dialog with all stakeholders. CTNBio is aware of these challenges and has already started to adjust the NR-5 to better guide the applicants in their writing of monitoring plans.
 
Designing molecules to bypass the singlet-triplet bottleneck in the electroluminescence of organic light-emitting-diode materials
Electroluminescence in organic light emitting diode (OLED) materials occurs
via the recombination of excitonic electrons-hole pairs Only the singlet
excitons of commonly used OLED materials, e.g., Aluminum trihydroxyquinoline
(AlQ), decay radiatively, limiting the external quantum efficiency to a
maximum 25%. Thus 75% of the energy is lost due to the triplet bottleneck for
radiative recombination. We consider molecules derived from AlQ which
bypass the triplet bottleneck by designing structures which contain strong
spin-orbit coupling. As a first stage of this work, groundstate energies and
vertical excitation energies of Al-arsenoquinolines and Al-boroarsenoquinolines
are calculated. It is found that the substitution of N by As leads to very
favourable results, while the boron substitution leads to no advantage.Comment: 4 pages, 4 figue
Pathological activation of KIT in metastatic tumors of acral and mucosal melanomas
ArticleINTERNATIONAL JOURNAL OF CANCER. 124(4):862-868 (2009)journal articl
Response of okra (Abelmoschus esculentus (L.) Moench) and soil chemical properties to different amendment types in an ultisol
A field experiment was carried out to investigate the effect of different organic manure on the growth and yield of okra (Abelmoschus esculentus (L.) Moench) at the teaching and research farm of the University of Benin, Benin City, Edo State, Nigeria between April to August, 2016. Four treatments; control (T1), cattle dung + poultry manure + pig manure (T2), poultry manure + foliar blend (T3) and bacterial inoculant (T4) were laid out in a randomized complete block design with four replications. Data were collected on growth (plant height, number of leaves, stem girth and leaf area) and yield parameters of okra plant. Results obtained from the research indicated that the growth and yield of okra was lowest in control (T1). These results further suggest that, the organic manure used in the study especially in a combined form (cattle dung + poultry manure + pig manure) positively influenced the agronomic performance of the okra plant. T2 increased okra plant height and, leaf area compared with the control. T3 recorded significantly higher number of leaves (7.188), compared with the control (3.375) whereas, fresh fruit weight from the various treatment plots were in the following order; T2 (79.15g) > T3 (53.58g) > T4 (22.53g) > T1 (20.24g). Although the nitrogen content of the soil was higher (21.33 g/kg) with T4, the highest fruit weight was obtained in T2 treated soils. It was also observed from the microbial analysis carried out on the soil samples obtained from the various plots that, soils with organic amendments (T2, T3 and T4) generally had higher microbial population, relative to control (T1). Based on the findings of this experiment, it could be deduced that cattle dung, poultry manure and pig manure promotes higher performance of okra.
 
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