Dynamics of <em>Prochlorococcus </em>Diversity and Photoacclimation During Short-Term Shifts in Water Column Stratification at Station ALOHA

\ua9 Copyright \ua9 2018 Thompson, van den Engh, Ahlgren, Kouba, Ward, Wilson and Karl.The cyanobacterium Prochlorococcus is the dominant phototroph in surface waters of the vast oligotrophic oceans, the foundation of marine food webs, and an important component of global biogeochemical cycles. The prominence of Prochlorococcus across the environmental gradients of the open ocean is attributed to its extensive genetic diversity and flexible chlorophyll physiology, enabling light capture over a wide range of intensities. What remains unknown is the balance between temporal dynamics of genetic diversity and chlorophyll physiology in the ability of Prochlorococcus to respond to a variety of short (approximately 1 day) and longer (months to year) changes in the environment. Previous field research established depth-dependent Prochlorococcus single cell chlorophyll distributions in the North Pacific Subtropical Gyre. Here, we examined whether the shifts in chlorophyll distributions correspond to changes in Prochlorococcus genetic diversity (i.e., ecotype-level community structure) or photoacclimation of stable communities over short time intervals. We report that community structure was relatively stable despite abrupt shifts in Prochlorococcus chlorophyll physiology, due to unexpected physiological plasticity of high-light adapted Prochlorococcus ecotypes. Through comparison with seasonal-scale changes, our data suggest that variability on daily scales triggers shifts in Prochlorococcus photoacclimation, while seasonal-scale dynamics trigger shifts in community structure. Together, these data highlight the importance of incorporating the process of photoacclimation and chlorophyll dynamics into interpretations of phytoplankton population dynamics from chlorophyll data as well as the importance of daily-scale variability to Prochlorococcus ecology

Investigation of A1g phonons in YBa2Cu3O7 by means of LAPW atomic-force calculations

We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A1g modes in YBa2Cu3O7. To establish the shape of the phonon potentials atomic forces are calculated within the LAPW method. Two different schemes - the local density approximation (LDA) and a generalized gradient approximation (GGA) - are employed for the treatment of electronic exchange and correlation effects. We find that in the case of LDA the resulting phonon frequencies show a deviation from experimental values of approximately -10%. Invoking GGA the frequency values are significantly improved and also the eigenvectors are in very good agreement with experimental findings.Comment: 15 page

Phonon dispersion and electron-phonon interaction for YBa_2Cu_3O_7 from first-principles calculations

We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the high-T_c superconductor YBa_2Cu_3O_7 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. The calculated phonon dispersion curves are in excellent agreement with Raman, infrared and neutron data. Calculation of the Eliashberg function alpha^2F leads to a small electron-phonon coupling lambda=0.27 in disagreement with earlier approximate treatments. Our calculations strongly support the view that conventional electron-phonon coupling is not an important contribution to superconductivity in high-T_c materials.Comment: 4 pages, 4 figure

Safety and efficacy of Taminizer D (dimethylglycine sodium salt) as a feed additive for chickens for fattening

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Taminizer D (dimethylglycine sodium salt) as a feed additive for chickens for fattening, based on a dossier submitted for the modification of the terms of authorisation of the additive. The product is authorised in the European Union for chickens for fattening at the maximum content of 1,000&nbsp;mg/kg complete feedingstuffs. The applicant proposed the introduction of an additional manufacturing process, which introduces an impurity (dimethylamino-ethanol (DMAE)) in the additive at concentrations up to 0.09%. The EFSA Panel&nbsp;on Additives and Products or Substances used in Animal Feed (FEEDAP) considered that the proposed modification would not substantially affect the previous assessment as related to the safety of the environment and the efficacy of the product. Since the safety of the active substance was established, the current assessment has dealt with the impurity DMAE. Considering the toxicological profile of DMAE, the estimated intake by the target animal and consumers, and making use of the Threshold of Toxicological Concern (TTC) approach, the Panel&nbsp;concluded that Taminizer D, manufactured by the DMAE route, is safe for both chickens for fattening and consumers, up to the maximum level of 1,000 mg/kg feed. The FEEDAP Panel&nbsp;extends its conclusions about Taminizer D produced by the original method to cover also Taminizer D produced by the new DMAE method. There is minimal risk to users from dust produced as a result of normal handling of the additive. Taminizer D is not irritant to skin but may be irritant to eyes; it is regarded as a potential skin sensitiser. The FEEDAP Panel&nbsp;recommended to set a specification for the DMAE content in the additive

Safety and efficacy of Kelforce \uae (l-glutamic acid, N,N-diacetic acid, tetrasodium salt (GLDA-Na 4 )) as a feed additive for chickens for fattening

l-Glutamic acid, N,N-diacetic acid, tetrasodium salt (GLDA-Na 4 ) (Kelforce \uae ) is sought to be used as a zootechnical feed additive in chickens for fattening to improve the absorption of zinc from feed, reducing zinc emissions through manure and thus, affecting favourably the environment. The product has not been authorised in the European Union as a feed additive. Kelforce \uae is intended to be marketed as a liquid and solid formulation, containing 65&nbsp;47% and 65&nbsp;30% of GLDA-Na 4 , respectively. Kelforce \uae is safe for chickens for fattening at the maximum level of 1,000&nbsp;mg GLDA-Na 4 /kg complete feed. Based on the toxicological profile of GLDA-Na 4 and the consumer exposure to GLDA-Na 4 and to nitrilotriacetic acid trisodium salt (NTA-Na 3 ; an impurity of the additive), the use of Kelforce \uae at the maximum proposed level in feed of chickens for fattening is of no concern for consumer safety. Due to its low inhalation toxicity, the exposure to GLDA-Na 4 is unlikely to pose a risk by inhalation. However, owing to the high-dusting potential of the solid formulation, a risk from such high level of dust, even if toxicologically inert, cannot be excluded. Kelforce \uae is not a skin/eye irritant or skin sensitiser. No risks for the terrestrial compartment were identified at the maximum use level of the additive. Risks for the aquatic compartment cannot be excluded based on the secondary effect of the additive on green algae. In the absence of data, the Panel&nbsp;cannot conclude on the safety for the sediment compartment or the possible ground water contamination. The risk of bioaccumulation and secondary poisoning caused by the additive is considered very low. Owing to the inconsistent and conflicting results from the studies assessed, the Panel&nbsp;on Additives and Products or Substances used in Animal Feed (FEEDAP) cannot conclude on the efficacy of the additive. The Panel&nbsp;made a recommendation regarding the levels of formaldehyde and cyanide in the active substance

The Quadrupole Magnets for the LHC Injection Transfer Lines

Two injection transfer lines, each about 2.8 km long, are being built to transfer protons at 450 GeV from the Super Proton Synchrotron (SPS) to the Large Hadron Collider (LHC). A total of 180 quadrupole magnets are required; they are produced in the framework of the contribution of the Russian Federation to the construction of the LHC. The classical quadrupoles, built from laminated steel cores and copper coils, have a core length of 1.4 m, an inscribed diameter of 32 mm and a strength of 53.5 T/m at a current of 530 A. The total weight of one magnet is 1.1 ton. For obtaining the required field quality at the small inscribed diameter, great care in the stamping of the laminations and the assembly of quadrants is necessary. Special instruments have been developed to measure, with a precision of some mm, the variations of the pole gaps over the full length of the magnet and correlate them to the obtained field distribution. The design has been developed in a collaboration between BINP and CERN. Fabrication and the magnetic measurements are done at BINP and should be finished at the end of the year 2000

Safety and efficacy of a natural mixture of dolomite plus magnesite and magnesium-phyllosilicates (Fluidol) as feed additive for all animal species

The additive, a natural mixture of dolomite plus magnesite and magnesium-phyllosilicates, is intended to be used as a technological additive (functional groups: anticaking agents) in feedingstuffs for all animal species. The additive is safe in complete feed for dairy cows, piglets and pigs for fattening at a maximum concentration of 20,000 mg/kg. No conclusions can be drawn for all the other animal species/categories. The additive is not genotoxic. As the additive is essentially not absorbed from the gut lumen, the Panel on Additives and Products or Substances used in Animal Feed considers that use of the additive in animal nutrition is safe for consumers of food products from animals fed diets containing the additive. The additive is not an irritant to the eyes and the skin, it is not a skin sensitiser and it is of low toxicity by the inhalation route. The components of the additive (dolomite, magnesite, talc and chlorite) are natural constituents of soil. Consequently, the use of the additive in animal nutrition will not pose a risk to the environment. The additive is effective as an anticaking agent at a minimum inclusion level of 5,000 mg/kg feed

Safety and efficacy of B&#8208;Act&#174; (Bacillus&#160;licheniformis DSM 28710) for chickens for fattening and chickens reared for laying

The additive B-Act\uae is a preparation containing viable spores of a strain of Bacillus licheniformis. The additive is intended for use in feed for chickens for fattening and chickens reared for laying at the proposed dose of 1.6 9 109 colony-forming unit (CFU)/kg complete feedingstuffs. B. licheniformis is considered by EFSA to be suitable for the qualified presumption of safety approach for establishing safety. As the identity of the active agent was established and the lack of toxigenic potential and resistance to antibiotics of human or veterinary clinical significance were demonstrated, the additive is presumed safe for the target species, consumers and the environment. In the absence of data, no conclusion can be drawn on the skin/eye irritation or skin sensitisation potential. The dustiness of the preparations tested indicated a potential for users to be exposed via inhalation. B-Act\uae should be considered to have the potential to be a respiratory sensitiser. B-Act\uae at the recommended dose 1.6 9 109 CFU/kg feed has some potential to improve the feed to gain ratio of chickens for fattening. This conclusion can be extended to chickens reared for laying when used at the same dose. B. licheniformis DSM 28710 is compatible with decoquinate, diclazuril, halofuginone, nicarbazin, robenidine hydrochloride, lasalocid A sodium, maduramicin ammonium, monensin sodium, narasin and salinomycin sodium