Detection of Emerging and Re-Emerging Pathogens in Surface Waters Close to an Urban Area

Current knowledge about the spread of pathogens in aquatic environments is scarce probably because bacteria, viruses, algae and their toxins tend to occur at low concentrations in water, making them very difficult to measure directly. The purpose of this study was the development and validation of tools to detect pathogens in freshwater systems close to an urban area. In order to evaluate anthropogenic impacts on water microbiological quality, a phylogenetic microarray was developed in the context of the EU project µAQUA to detect simultaneously numerous pathogens and applied to samples from two different locations close to an urban area located upstream and downstream of Rome in the Tiber River. Furthermore, human enteric viruses were also detected. Fifty liters of water were collected and concentrated using a hollow-fiber ultrafiltration approach. The resultant concentrate was further size-fractionated through a series of decreasing pore size filters. RNA was extracted from pooled filters and hybridized to the newly designed microarray to detect pathogenic bacteria, protozoa and toxic cyanobacteria. Diatoms as indicators of the water quality status, were also included in the microarray to evaluate water quality. The microarray results gave positive signals for bacteria, diatoms, cyanobacteria and protozoa. Cross validation of the microarray was performed using standard microbiological methods for the bacteria. The presence of oral-fecal transmitted human enteric-viruses were detected using q-PCR. Significant concentrations of Salmonella, Clostridium, Campylobacter and Staphylococcus as well as Hepatitis E Virus (HEV), noroviruses GI (NoGGI) and GII (NoGII) and human adenovirus 41 (ADV 41) were found in the Mezzocammino site, whereas lower concentrations of other bacteria and only the ADV41 virus was recovered at the Castel Giubileo site. This study revealed that the pollution level in the Tiber River was considerably higher downstream rather than upstream of Rome and the downstream location was contaminated by emerging and re-emerging pathogens.

Getting Close to the Action: The Micro-Politics of Rural Development

This article identifies and positions micro-politics within rural development practice. It is concerned with the hidden and subtle processes that bind groups together, including trust, power and personal perceptions and motivations. The first section of the article provides a theoretical context for micro-political processes which reveals subtle distinctions from social capital. The section following describes the ethnographic approach that sets the methodological framework for the research. The findings reveal how micro-political processes manifest in a rural development group affect norms and relations both positively and negatively. Finally the causes of and factors affecting micro-politics are considered before concluding with a discussion on how micro-politics may be managed in rural regeneration.

Proof of polar ejection from the close-binary core of the planetary nebula Abell 63

We present the first detailed kinematical analysis of the planetary nebula Abell 63, which is known to contain the eclipsing close-binary nucleus UU Sge. Abell 63 provides an important test case in investigating the role of close-binary central stars on the evolution of planetary nebulae. Longslit observations were obtained using the Manchester echelle spectrometer combined with the 2.1-m San Pedro Martir Telescope. The spectra reveal that the central bright rim of Abell 63 has a tube-like structure. A deep image shows collimated lobes extending from the nebula, which are shown to be high-velocity outflows. The kinematic ages of the nebular rim and the extended lobes are calculated to be 8400 +/- 500 and 12900 +/- 2800 yr, respectively, which suggests that the lobes were formed at an earlier stage than the nebular rim. This is consistent with expectations that disc-generated jets form immediately after the common envelope phase. A morphological-kinematical model of the central nebula is presented and the best-fitting model is found to have the same inclination as the orbital plane of the central binary system; this is the first proof that a close-binary system directly affects the shaping of its nebula. A Hubble-type flow is well-established in the morphological-kinematical modelling of the observed line profiles and imagery. Two possible formation models for the elongated lobes of Abell 63 are considered, (i) a low-density, pressure-driven jet excavates a cavity in the remnant asymptotic giant branch (AGB) envelope; (ii) high-density bullets form the lobes in a single ballistic ejection event.

Electron-impact ionization of atomic hydrogen close to threshold

A systematic study of the ionization of atomic hydrogen by electron impact from 0.3 eV to a few eV above the ionization threshold has been carried out using a semiclassical-quantal calculation. Differential and integrated cross sections are presented at 0.3 eV above the energy threshold. Triple- differential cross sections (TDCS) are presented at constant theta(12) geometry where theta(12)=180degrees and 150degrees. Good agreement is achieved with the measurement [Roder, Phys. Rev. Lett. 79, 1666 (1997)] and calculations based on exterior complex scaling at 2 eV and 4 eV above threshold. Results of triple-differential cross sections are also presented at 0.3, 0.5, and 1.0 eV above threshold at both theta(12)=180degrees and 150degrees. At theta(12)=180degrees the small local maximum in the TDCS around theta(1)=90degrees reported by Pan and Starace [Phys. Rev. A 45, 4588 (1992)] at 0.5 eV above threshold is not observed in our calculation at energies down to 0.3 eV above threshold. The shape of our double differential cross sections seems to disagree qualitatively with the available calculations as we found two local maxima around 15degrees and 165degrees in our calculation. Single differential cross sections in our formulation appear naturally as a function of total excess energy E and, therefore, constant for all combinations of individual electron energies E-1 and E- 2 with E=E-1+E-2. Total ionization cross sections are also compared with measurement and available theoretical calculations and found to be in reasonably good agreement up to 10 eV above ionization threshold.

Biochemical characterization of the equine arteritis virus helicase suggests a close functional relationship between arterivirus and coronavirus helicases.

The arterivirus equine arteritis virus nonstructural protein 10 (nsp10) has previously been predicted to contain a Zn finger structure linked to a superfamily 1 (SF1) helicase domain. A recombinant form of nsp10, MBP-nsp10, was produced in Escherichia coli as a fusion protein with the maltose-binding protein. The protein was partially purified by affinity chromatography and shown to have ATPase activity that was strongly stimulated by poly(dT), poly(U), and poly(dA) but not by poly(G). The protein also had both RNA and DNA duplex-unwinding activities that required the presence of 5' single-stranded regions on the partial-duplex substrates, indicating a 5'-to-3' polarity in the unwinding reaction. Results of this study suggest a close functional relationship between the arterivirus nsp10 and the coronavirus helicase, for which NTPase and duplex-unwinding activities were recently demonstrated. In a number of biochemical properties, both arterivirus and coronavirus SF1 helicases differ significantly from the previously characterized RNA virus SF1 and SF2 enzymes. Thus, the combined data strongly support the idea that nidovirus helicases may represent a separate group of RNA virus-encoded helicases with distinct properties.

‘Close as a kiss’: Gyn/Affection in Margaret Atwood’s The Penelopiad

Margaret Atwood’s novella The Penelopiad (2005) seemingly celebrates Penelope’s agency in opposition to Homer’s myth in The Odyssey. However, the twelve murdered maids steal the book to suggest the possibility of what Janice Raymond calls gyn/affection, a female bonding based on the logic of emotion that, in Atwood’s revision, verges on Kristevan abjection, the sinister and the fantastic, and serves a cathartic effect not only in the maids but also in the reader. This essay aims to question the generally accepted empowerment of Atwood’s Penelope and celebrates the murdered maids as the locus of emotion, where marginal aspects of gender and class merge to weave a powerful metaphorical tapestry of popular and traditionally feminized literary genres that, in plunging into and embracing the semiotic realm, ultimately solidify into an eclectic but compact alternative tradition of women’s writing and myth-making.

A density functional theory study of the reaction of C+O, C+N, and C+H on close packed metal surfaces

Density functional theory (DFT) has been used to determine reaction pathways for several reactions taking place on Pt(111) and Cu(111) surfaces. On Pt(111), the reactions of C+O and C+N were studied, and on Cu(111) we investigated the reaction of C+H. The structures of the transition states accessed in each reaction are similar. An equivalent distance separates the reactants with the first located at a three-fold hollow site and the second close to a bridge site. Previous DFT studies have, in fact, often identified transition states of this type and in every case it is the reactant with the weaker chemisorption energy that is located close to the bridge site. An explanation as to why this is so is provided. (C) 2001 American Institute of Physics.

WASP-24 b: A New Transiting Close-in Hot Jupiter Orbiting a Late F-star

We report the discovery of a new transiting close-in giant planet, WASP-24 b, in a 2.341 day orbit, 0.037 AU from its F8-9 type host star. By matching the star's spectrum with theoretical models, we infer an effective temperature T eff = 6075 ± 100 K and a surface gravity of log g = 4.15 ± 0.10. A comparison of these parameters with theoretical isochrones and evolutionary mass tracks places only weak constraints on the age of the host star, which we estimate to be 3.8+1.3 –1.2 Gyr. The planetary nature of the companion was confirmed by radial velocity measurements and additional photometric observations. These data were fit simultaneously in order to determine the most probable parameter set for the system, from which we infer a planetary mass of 1.071+0.036 –0.038 M Jup and radius 1.3+0.039 –0.037 R Jup.