Effective monitoring for ractopamine residues in samples of animal origin by SPR biosensor and mass spectrometry

Ractopamine (RCT) is a member of the beta-2-agonist (beta-agonist) family. It is licensed for use as an animal growth promoter in more than 20 countries worldwide, including the United States and Canada, but is either not licensed or prohibited by over 150 others, including those within the European Union. The issue of the use of RCT in livestock bound for human consumption has risen to prominence recently following the decision by The People's Republic of China to ban the import of pork from a number of processing plants after finding traces of RCT in shipments from the U.S.A.

Ultra-bright Optical Transients are Linked with Type Ic Supernovae

Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries of SN 2005ap by the Texas Supernova Search and SCP-06F6 in a deep Hubble pencil beam survey were followed by the Palomar Transient Factory confirmation of host redshifts for other similar transients. The transients share the common properties of high optical luminosities (peak magnitudes similar to -21 to -23), blue colors, and a lack of H or He spectral features. The physical mechanism that produces the luminosity is uncertain, with suggestions ranging from jet-driven explosion to pulsational pair instability. Here, we report the most detailed photometric and spectral coverage of an ultra-bright transient (SN 2010gx) detected in the Pan-STARRS 1 sky survey. In common with other transients in this family, early-time spectra show a blue continuum and prominent broad absorption lines of O II. However, about 25 days after discovery, the spectra developed type Ic supernova features, showing the characteristic broad Fe II and Si II absorption lines. Detailed, post-maximum follow-up may show that all SN 2005ap and SCP-06F6 type transients are linked to supernovae Ic. This poses problems in understanding the physics of the explosions: there is no indication from late-time photometry that the luminosity is powered by Ni-56, the broad light curves suggest very large ejected masses, and the slow spectral evolution is quite different from typical Ic timescales. The nature of the progenitor stars and the origin of the luminosity are intriguing and open questions.

Phonons, Instabilities and Origin of Polarization in KDP Crystals

The -phonons of KH2PO4 (KDP) and its deuterated analog DKDP are studied via first-principles linear response calculations. The paraelectric phase shows two instabilities. One for a z-polarized mode, which leads to the spontaneous polarization Ps of the ferroelectric phase. The other corresponds to a two-fold degenerate xy-polarized mode. Other phonons are analyzed, which couple to the ferroelectric one at large amplitudes and are relevant for the ferroelectric transition. We show that Ps is mainly of electronic nature, since it arises mostly from an off-diagonal component of the Born effective charge tensor of H, with minor contribution from P atoms displacements.

Antimicrobial prescribing in Nursing Homes in Northern Ireland: Results of Two Point-Prevalence Surveys

BACKGROUND: In 2005, the European Commission recommended that all member states should establish or strengthen surveillance systems for monitoring the use of antimicrobial agents. There is no evidence in the literature of any surveillance studies having been specifically conducted in nursing homes (NHs) in Northern Ireland (NI).

OBJECTIVE: The aim of this study was to determine the prevalence of antimicrobial prescribing and its relationship with certain factors (e.g. indwelling urinary catheterization, urinary incontinence, disorientation, etc.) in NH residents in NI.

METHODS: This project was carried out in NI as part of a wider European study under the protocols of the European Surveillance of Antimicrobial Consumption group. Two point-prevalence surveys (PPSs) were conducted in 30 NHs in April and November 2009. Data were obtained from nursing notes, medication administration records and staff in relation to antimicrobial prescribing, facility and resident characteristics and were analysed descriptively.

RESULTS: The point prevalence of antimicrobial prescribing was 13.2% in April 2009 and 10.7% in November 2009, with a 10-fold difference existing between the NHs with the highest and lowest antimicrobial prescribing prevalence during both PPSs. The same NH had the highest rate of antimicrobial prescribing during both April (30.6%) and November (26.0%). The group of antimicrobials most commonly prescribed was the penicillins (April 28.6%, November 27.5%) whilst the most prevalent individual antimicrobial prescribed was trimethoprim (April 21.3%, November 24.3%). The majority of antimicrobials were prescribed for the purpose of preventing urinary tract infections (UTIs) in both April (37.8%) and in November (46.7%), with 5% of all participating residents being prescribed an antimicrobial for this reason. Some (20%) antimicrobials were prescribed at inappropriate doses, particularly those which were used for the purpose of preventing UTIs. Indwelling urinary catheterization and wounds were significant risk factors for antimicrobial use in April [odds ratio {OR} (95% CI) 2.0 (1.1, 3.5) and 1.8 (1.1, 3.0), respectively] but not in November 2009 [OR (95% CI) 1.6 (0.8, 3.2) and 1.2 (0.7, 2.2), respectively]. Other resident factors, e.g. disorientation, immobility and incontinence, were not associated with antimicrobial use. Furthermore, none of the NH characteristics investigated (e.g. number of beds, hospitalization episodes, number of general practitioners, etc.) were found to be associated with antimicrobial use in either April or November 2009.

CONCLUSIONS: This study has identified a high overall rate of antimicrobial use in NHs in NI, with variability evident both within and between homes. More research is needed to understand which factors influence antimicrobial use and to determine the appropriateness of antimicrobial prescribing in this population in general and more specifically in the management of recurrent UTIs.

Origin of Low CO2 Selectivity on Platinum in the Direct Ethanol Fuel Cell

Calculated answer: First-principles calculations have been applied to calculate the energy barrier for the key step in CO formation on a Pt surface (see picture; Pt blue, Pt atoms on step edge yellow) to understand the low CO2 selectivity in the direct ethanol fuel cell. The presence of surface oxidant species such as O (brown bar) and OH (red bar) led to an increase of the energy barrier and thus an inhibition of the key step. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Surveillance of cerebral palsy in Europe: a collaboration of cerebral palsy surveys and registers

Although cerebral palsy (CP) is the most common cause of motor deficiency in young children, it occurs in only 2 to 3 per 1000 live births. In order to monitor prevalence rates, especially within subgroups (birthweight, clinical type), it is necessary to study large populations. A network of CP surveys and registers was formed in 14 centres in eight countries across Europe. Differences in prevalence rates of CP in the centres prior to any work on harmonization of data are reported. The subsequent process to standardize the definition of CP, inclusion/exclusion criteria, classification, and description of children with CP is outlined. The consensus that was reached on these issues will make it possible to monitor trends in CP rate, to provide a framework for collaborative research, and a basis for services planning among European countries.

Genomic insights into the origin of parasitism in the emerging plant pathogen Bursaphelenchus xylophilus.

Bursaphelenchus xylophilus is the nematode responsible for a devastating epidemic of pine wilt disease in Asia and Europe, and represents a recent, independent origin of plant parasitism in nematodes, ecologically and taxonomically distinct from other nematodes for which genomic data is available. As well as being an important pathogen, the B. xylophilus genome thus provides a unique opportunity to study the evolution and mechanism of plant parasitism. Here, we present a high-quality draft genome sequence from an inbred line of B. xylophilus, and use this to investigate the biological basis of its complex ecology which combines fungal feeding, plant parasitic and insect-associated stages. We focus particularly on putative parasitism genes as well as those linked to other key biological processes and demonstrate that B. xylophilus is well endowed with RNA interference effectors, peptidergic neurotransmitters (including the first description of ins genes in a parasite) stress response and developmental genes and has a contracted set of chemosensory receptors. B. xylophilus has the largest number of digestive proteases known for any nematode and displays expanded families of lysosome pathway genes, ABC transporters and cytochrome P450 pathway genes. This expansion in digestive and detoxification proteins may reflect the unusual diversity in foods it exploits and environments it encounters during its life cycle. In addition, B. xylophilus possesses a unique complement of plant cell wall modifying proteins acquired by horizontal gene transfer, underscoring the impact of this process on the evolution of plant parasitism by nematodes. Together with the lack of proteins homologous to effectors from other plant parasitic nematodes, this confirms the distinctive molecular basis of plant parasitism in the Bursaphelenchus lineage. The genome sequence of B. xylophilus adds to the diversity of genomic data for nematodes, and will be an important resource in understanding the biology of this unusual parasite.

Complex sociogenetic organization and the origin of unrelated workers in a eusocial sweat bee, Lasioglossum malachurum

Sweat bees (Halictidae) exhibit great interspecific and intraspecific diversity in their social organisation, yet there is remarkably little information on the sociogenetic organisation of any species. Lasioglossum malachurum is a eusocial sweat bee with an annual lifecycle that exhibits considerable variation in its social organisation across its wide geographic range from northern to southern Europe. We collected all adults from 31 L. malachurum nests at Eichkogl, Austria, near the latitudinal centre of its distribution, and genotyped 148 workers using 5 highly variable microsatellite loci developed for this species. Nests were often queenless (48% of nests) during the second phase of worker activity, when colonies were provisioning the sexual brood. Pedigree reconstruction and estimates of nestmate genetic relatedness demonstrated that nests often (32% of nests) contained alien workers, probably as a result of worker drifting from their natal to a foreign nest. Queen effective mating frequency was variable (harmonic mean m(e) = 1.24), but sometimes high (maximum 2.7). These data demonstrate that nests of L. malachurum do not have a classical eusocial sociogenetic organisation (monogyny, monandry) and thereby pose a challenge to exclusively relatedness based arguments for the evolution of eusociality in the taxon.

ON THE ORIGIN OF NH IN DIFFUSE INTERSTELLAR CLOUDS

The observation by Meyer & Roch of NH in the interstellar clouds towards zeta Per and HD 27778 cannot be explained with conventional gas-phase chemistry models. A simple non-equilibrium model for the zeta Per cloud, which incorporates the grain-surface production of NH and OH or, alternatively, NH3 and H2O, is able to reproduce the abundances of all observed species (except CH+) quite accurately. Moreover, chemical models which include grain-surface reactions can reproduce the observed abundance not only of NH but also of CN, which is efficiently formed at low temperatures, initiated by the reaction of NH with C+. Pure gas-phase models and cloud interface models, in which NH and CH+ are formed in a warm and tenuous environment, fail to explain the observed high abundance of CN. Hence the observation of NH in zeta Per and HD 27778 provides evidence for the presence of grain-surface reactions leading to molecules other than H-2. It is predicted that NH2 and NH3 should have abundances not much below that of NH if NH3 instead of NH is formed on grains. With or without surface reactions, the column densities of H2O and C2H are expected to be about 10(13) cm-2, and these molecules may be detectable in the zeta Per cloud.

The Origin of Type I Spicule Oscillations

We use images of high spatial and temporal resolution, obtained with the Rapid Oscillations in the Solar Atmosphere instrument at the Dunn Solar Telescope, to reveal how the generation of transverse waves in Type I spicules is a direct result of longitudinal oscillations occurring in the photosphere. Here we show how pressure oscillations, with periodicities in the range of 130–440 s, manifest in small-scale photospheric magnetic bright points, and generate kink waves in the Sun’s outer atmosphere with transverse velocities approaching the local sound speed. Through comparison of our observations with advanced two-dimensional magnetohydrodynamic simulations, we provide evidence for how magnetoacoustic oscillations, generated at the solar surface, funnel upward along Type I spicule structures, before undergoing longitudinal-to-transverse mode conversion into waves at twice the initial driving frequency. The resulting kink modes are visible in chromospheric plasma, with periodicities of 65–220 s, and amplitudes often exceeding 400 km. A sausage mode oscillation also arises as a consequence of the photospheric driver, which is visible in both simulated and observational time series. We conclude that the mode conversion and period modi?cation is a direct consequence of the 90? phase shift encompassing opposite sides of the photospheric driver. The chromospheric energy ?ux of these waves are estimated to be ˜3 × 105 W m-2, which indicates that they are suf?ciently energetic to accelerate the solar wind and heat the localized corona to its multi-million degree temperatures.

Core-collapse supernovae in low-metallicity environments and future all-sky transient surveys

Aims. Massive stars in low-metallicity environments may produce exotic explosions such as long-duration gamma-ray bursts and pair-instability supernovae when they die as core-collapse supernovae (CCSNe). Such events are predicted to be relatively common in the early Universe during the first episodes of star-formation. To understand these distant explosions it is vital to study nearby CCSNe arising in low-metallicity environments to determine if the explosions have different characteristics to those studied locally in high-metallicity galaxies. Many of the nearby supernova searches concentrate their efforts on high star-formation rate galaxies, hence biasing the discoveries to metal rich regimes. Here we determine the feasibility of searching for these CCSNe in metal-poor dwarf galaxies using various survey strategies.