Aims
To determine the seasonal occurrence and diversity of norovirus (NoV) and human adenovirus (HAdV) in groundwater from sinkholes, and brackish water used for recreational activities in the karst ...aquifer of the Yucatan Peninsula, Mexico.
Methods and results
Hollow fibre ultrafiltration was used to concentrate viruses and standard plaque assay methods were used to enumerate somatic and F+ specific coliphages as viral indicators. Real‐time quantitative polymerase chain reaction assays were used to estimate the number of genome copies for NoV strains GI, and GII, and HAdVs. The predominant NoV genotypes and HAdV serotypes were identified by comparative sequence analysis. Somatic and male F+ specific coliphages were detected at concentrations up to 94 and 60 plaque‐forming units per 100 ml respectively. The NoV genogroup I (GI) was associated with 50% of the sampled sites during the rainy season only, at concentrations ranging from 120 to 1600 genome copies per litre (GC l−1). The NoV genogroup II (GII) was detected in 30 and 40% of the sampled sites during the rainy and dry seasons, respectively, at concentrations ranging from 10 to 290 GC l−1. During the rainy and dry seasons, HAdVs were detected in 20% of the sites, at concentrations ranging from 24 to 690 GC l−1. Identification of viral types revealed the presence of NoV GI.2, GII.Pe, GII.P16 and GII.P17, and HAdV F serotypes 40 and 41.
Conclusions
These findings demonstrate that NoVs and HAdVs are prevalent as virus contaminants in the karst aquifer, representing potential health risks particularly during the rainy season, in one of the most important areas used for tourism in Mexico.
Significance and Impact of the Study
This is one of the few studies conducted in karst aquifers that provide a foundational baseline of the distribution, concentrations and diversity of NoVs and HadVs in these particular environments.
Presumed incompetent Gutierrez y Muhs, Gabriella; Niemann, Yolanda Flores; Gonzalez, Carmen G ...
2012, 20120521, 2012-10-31
eBook, Book
Presumed Incompetent is a pathbreaking account of the intersecting roles of race, gender, and class in the working lives of women faculty of color. Through personal narratives and qualitative ...empirical studies, more than 40 authors expose the daunting challenges faced by academic women of color as they navigate the often hostile terrain of higher education, including hiring, promotion, tenure, and relations with students, colleagues, and administrators. The narratives are filled with wit, wisdom, and concrete recommendations, and provide a window into the struggles of professional women in a racially stratified but increasingly multicultural America.
We present new measurements of the evolution of the X-ray luminosity functions (XLFs) of unabsorbed and absorbed active galactic nuclei (AGNs) out to z ∼ 5. We construct samples containing 2957 ...sources detected at hard (2–7 keV) X-ray energies and 4351 sources detected at soft (0.5–2 keV) energies from a compilation of Chandra surveys supplemented by wide-area surveys from ASCA and ROSAT. We consider the hard and soft X-ray samples separately and find that the XLF based on either (initially neglecting absorption effects) is best described by a new flexible model parametrization where the break luminosity, normalization, and faint-end slope all evolve with redshift. We then incorporate absorption effects, separately modelling the evolution of the XLFs of unabsorbed (20 < log N
H < 22) and absorbed (22 < log N
H < 24) AGNs, seeking a model that can reconcile both the hard- and soft-band samples. We find that the absorbed AGN XLF has a lower break luminosity, a higher normalization, and a steeper faint-end slope than the unabsorbed AGN XLF out to z ∼ 2. Hence, absorbed AGNs dominate at low luminosities, with the absorbed fraction falling rapidly as luminosity increases. Both XLFs undergo strong luminosity evolution which shifts the transition in the absorbed fraction to higher luminosities at higher redshifts. The evolution in the shape of the total XLF is primarily driven by the changing mix of unabsorbed and absorbed populations.
We present and discuss the Smithsonian Astrophysical Observatory (SAO) formaldehyde (H2CO) retrieval algorithm for the Ozone Monitoring Instrument (OMI) which is the operational retrieval for NASA ...OMI H2CO. The version of the algorithm described here includes relevant changes with respect to the operational one, including differences in the reference spectra for H2CO, the fit of O2–O2 collisional complex, updates in the high-resolution solar reference spectrum, the use of a model reference sector over the remote Pacific Ocean to normalize the retrievals, an updated air mass factor (AMF) calculation scheme, and the inclusion of scattering weights and vertical H2CO profile in the level 2 products. The setup of the retrieval is discussed in detail. We compare the results of the updated retrieval with the results from the previous SAO H2CO retrieval. The improvement in the slant column fit increases the temporal stability of the retrieval and slightly reduces the noise. The change in the AMF calculation has increased the AMFs by 20%, mainly due to the consideration of the radiative cloud fraction. Typical values for retrieved vertical columns are between 4 × 1015 and 4 × 1016 molecules cm−2, with typical fitting uncertainties ranging between 45 and 100%. In high-concentration regions the errors are usually reduced to 30%. The detection limit is estimated at 1 × 1016 molecules cm−2.
We found that multiwalled carbon nanotubes (MWNTs) can be opened longitudinally by intercalation of lithium and ammonia followed by exfoliation. Intercalation of open-ended tubes and exfoliation with ...acid treatment and abrupt heating provided the best results. The resulting material consists of: (i) multilayered flat graphitic structures (nanoribbons), (ii) partially open MWNTs, and (iii) graphene flakes. We called the completely unwrapped nanotubes ex-MWNTs, and their large number of edge atoms makes them attractive for many applications.
•Occurrence of antibiotics in wastewater and seawater from Antarctic was evaluated.•Quinolones and macrolides were the most found in wastewater from several stations.•Detailed study made to ensure ...quality control of analysis during sample collection and treatment, and shipping of samples.•Bacteria resistance (E. Coli) was observed for several groups of antibiotics.•Periodical monitoring of pharmaceuticals in waters and additional treatments in WWTPs are required.
The potential presence of introduced antibiotics in the aquatic environment is a hot topic of concern, particularly in the Antarctic, a highly vulnerable area protected under the Madrid protocol. The increasing presence of human population, especially during summer, might led to the appearance of pharmaceuticals in wastewater. The previous discovery of Escherichia coli strains resistant to antibiotics in sea water and wastewater collected in King George Island motivated our investigation on antibiotics occurrence in these samples. The application of a multi-residue LCMS/MS method for 20 antibiotics, revealed the presence of 8 compounds in treated wastewater, mainly the quinolones ciprofloxacin and norfloxacin (92% and 54% of the samples analyzed, average concentrations 0.89 μg/L and 0.75 μg/L, respectively) and the macrolides azithromycin and clarithromycin (15% positive samples, and average concentrations near 0.4 μg/L), and erythromycin (38% positive samples, average concentration 0.003 μg/L). Metronidazole and clindamycin were found in one sample, at 0.17 and 0.1 μg/L, respectively; and trimethoprim in two samples, at 0.001 μg/L. Analysis of sea water collected near the outfall of the wastewater discharges also showed the sporadic presence of 3 antibiotics (ciprofloxacin, clindamycin, trimethoprim) at low ng/L level, illustrating the impact of pharmaceuticals consumption and the poor removal of these compounds in conventional WWTPs. The most widespread antibiotic in sea water was ciprofloxacin, which was found in 15 out of 34 sea water samples analyzed, at concentrations ranging from 4 to 218 ng/L. Bacteria resistance was observed for some antibiotics identified in the samples (e.g. trimetropim and nalidixic acid –a first generation quinolone). However, resistance to some groups of antibiotics could not be correlated to their presence in the water samples due to analytical limitations (penicillins, tetraciclines). On the contrary, for some groups of antibiotics detected in samples (macrolides), the antibacterial activity against E. Coli was not investigated because these antibiotics do not include this bacterial species in their spectrum of activity.
Our preliminary data demonstrate that antibiotics occurrence in the Antarctic aquatic environment is an issue that needs to be properly addressed. Periodical monitoring of water samples and the implementation of additional treatments in the WWTPs are recommended as a first step to prevent potential problems related to the presence of antibiotics and other emerging contaminants in the near future in Antarctica.
The Myogenic Regulatory Factors (MRFs) Myf5, MyoD, myogenin and MRF4 are members of the basic helix-loop-helix family of transcription factors that control the determination and differentiation of ...skeletal muscle cells during embryogenesis and postnatal myogenesis. The dynamics of their temporal and spatial expression as well as their biochemical properties have allowed the identification of a precise and hierarchical relationship between the four MRFs. This relationship establishes the myogenic lineage as well as the maintenance of the terminal myogenic phenotype. The application of genome-wide technologies has provided important new information as to how the MRFs function to activate muscle gene expression. Application of combined functional genomics technologies along with single cell lineage tracing strategies will allow a deeper understanding of the mechanisms mediating myogenic determination, cell differentiation and muscle regeneration.
Summary
Aims
Canagliflozin is a sodium glucose co‐transporter 2 inhibitor developed for the treatment of type 2 diabetes mellitus (T2DM). This randomised, double‐blind, placebo‐controlled, Phase 3 ...study evaluated the efficacy and safety of canagliflozin as an add‐on to metformin plus sulphonylurea in patients with T2DM.
Methods
Patients (N = 469) received canagliflozin 100 or 300 mg or placebo once daily during a 26‐week core period and a 26‐week extension. Prespecified primary end‐point was change in HbA1c at 26 weeks. Secondary end‐points included change in HbA1c at week 52 as well as proportion of patients achieving HbA1c < 7.0%, change in fasting plasma glucose (FPG) and systolic blood pressure, and per cent change in body weight, high‐density lipoprotein cholesterol, and triglycerides (weeks 26 and 52).
Results
HbA1c was significantly reduced with canagliflozin 100 and 300 mg vs. placebo at week 26 (–0.85%, –1.06%, and –0.13%; p < 0.001); these reductions were maintained at week 52 (–0.74%, –0.96%, and 0.01%). Both canagliflozin doses reduced FPG and body weight vs. placebo at week 26 (p < 0.001) and week 52. Overall adverse event (AE) rates were similar across groups over 52 weeks, with higher rates of genital mycotic infections and osmotic diuresis‐related AEs seen with canagliflozin vs. placebo; these led to few discontinuations. Increased incidence of documented, but not severe, hypoglycaemia episodes was seen with canagliflozin vs. placebo.
Conclusions
Canagliflozin improved glycaemic control, reduced body weight, and was generally well tolerated in T2DM patients on metformin plus sulphonylurea over 52 weeks.
ABSTRACT
The diffuse extragalactic background light (EBL) is formed by ultraviolet (UV), optical, and infrared (IR) photons mainly produced by star formation processes over the history of the ...Universe and contains essential information about galaxy evolution and cosmology. Here, we present a new determination of the evolving EBL spectral energy distribution using a novel approach purely based on galaxy data aiming to reduce current uncertainties on the higher redshifts and IR intensities. Our calculations use multiwavelength observations from the UV to the far-IR of a sample of approximately 150 000 galaxies detected up to z ∼ 6 in the five fields of the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey from the Hubble Space Telescope. This is one of the most comprehensive and deepest multiwavelength galaxy data sets ever obtained. These unprecedented resources allow us to derive the overall EBL evolution up to z ∼ 6 and its uncertainties. Our results agree with cosmic observables estimated from galaxy surveys and γ-ray attenuation such as monochromatic luminosity densities, including those in the far-IR, and star formation rate densities, also at the highest redshifts. Optical depths from our EBL approximation, which will be robust at high redshifts and for γ-rays up to tens of TeV, will be reported in a companion paper.
In the central region of the Gulf of Mexico, urban growth occurs mainly to support tourism and results in loss of natural ecosystems and ecosystem services. Our objectives were to analyze land use ...changes and calculate the value of these changes in terms of lost ecosystem services. We selected three study sites with contrasting infrastructure for tourism: Boca del Río, Chachalacas and Costa Esmeralda. From 1995–2006, we found that urban sprawl was predominant, and occurred over mangroves, grasslands, croplands and the beach. Using the benefit transfer method, we calculated a net loss ($US 2006/ha/year) of $1.4×103 in Boca del Río, $7×105 in Chachalacas and $1×105 in Costa Esmeralda. Because the value of urban land is higher (from 45,000 USD/ha (2006) in Costa Esmeralda to 6million in Boca del Río) than the total estimated Ecosystem Services Value (106,000 USD/ha, including all ecosystems and ecosystem services), land use change may seem economically profitable. However, after losing ecosystem services such as coastal protection or scenic value and recreation, the apparent gains from urban development are lost. Land use and policy making should consider ecosystem service losses so that ecosystems are preserved and society benefited.
► In the Gulf of Mexico urban growth occurs in places of high tourism importance. ► We studied land use changes and calculated the value of lost ecosystem services. ► We selected three study sites with contrasting tourism activities and infrastructure. ► Urban sprawl was dominant and occurred at the expense of natural ecosystems. ► Land use change resulted in important losses that surpass the immediate gains of urbanization.
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