Assessment of the occurrence and potential risks of antibiotics and their metabolites in South Florida waters using liquid chromatography tandem mass spectrometry

An automated on-line SPE-LC-MS/MS method was developed for the quantitation of multiple classes of antibiotics in environmental waters. High sensitivity in the low ng/L range was accomplished by using large volume injections with 10-mL of sample. Positive confirmation of analytes was achieved using two selected reaction monitoring (SRM) transitions per antibiotic and quantitation was performed using an internal standard approach. Samples were extracted using online solid phase extraction, then using column switching technique; extracted samples were immediately passed through liquid chromatography and analyzed by tandem mass spectrometry. The total run time per each sample was 20 min. The statistically calculated method detection limits for various environmental samples were between 1.2 and 63 ng/L. Furthermore, the method was validated in terms of precision, accuracy and linearity. ^ The developed analytical methodology was used to measure the occurrence of antibiotics in reclaimed waters (n=56), surface waters (n=53), ground waters (n=8) and drinking waters (n=54) collected from different parts of South Florida. In reclaimed waters, the most frequently detected antibiotics were nalidixic acid, erythromycin, clarithromycin, azithromycin trimethoprim, sulfamethoxazole and ofloxacin (19.3-604.9 ng/L). Detection of antibiotics in reclaimed waters indicates that they can't be completely removed by conventional wastewater treatment process. Furthermore, the average mass loads of antibiotics released into the local environment through reclaimed water were estimated as 0.248 Kg/day. Among the surface waters samples, Miami River (reaching up to 580 ng/L) and Black Creek canal (up to 124 ng/L) showed highest concentrations of antibiotics. No traces of antibiotics were found in ground waters. On the other hand, erythromycin (monitored as anhydro erythromycin) was detected in 82% of the drinking water samples (n.d-66 ng/L). The developed approach is suitable for both research and monitoring applications.^ Major metabolites of antibiotics in reclaimed wates were identified and quantified using high resolution benchtop Q-Exactive orbitrap mass spectrometer. A phase I metabolite of erythromycin was tentatively identified in full scan based on accurate mass measurement. Using extracted ion chromatogram (XIC), high resolution data-dependent MS/MS spectra and metabolic profiling software the metabolite was identified as desmethyl anhydro erythromycin with molecular formula C36H63NO12 and m/z 702.4423. The molar concentration of the metabolite to erythromycin was in the order of 13 %. To my knowledge, this is the first known report on this metabolite in reclaimed water. Another compound acetyl-sulfamethoxazole, a phase II metabolite of sulfamethoxazole was also identified in reclaimed water and mole fraction of the metabolite represent 36 %, of the cumulative sulfamethoxazole concentration. The results were illustrating the importance to include metabolites also in the routine analysis to obtain a mass balance for better understanding of the occurrence, fate and distribution of antibiotics in the environment. ^ Finally, all the antibiotics detected in reclaimed and surface waters were investigated to assess the potential risk to the aquatic organisms. The surface water antibiotic concentrations that represented the real time exposure conditions revealed that the macrolide antibiotics, erythromycin, clarithromycin and tylosin along with quinolone antibiotic, ciprofloxacin were suspected to induce high toxicity to aquatic biota. Preliminary results showing that, among the antibiotic groups tested, macrolides posed the highest ecological threat, and therefore, they may need to be further evaluated with, long-term exposure studies considering bioaccumulation factors and more number of species selected. Overall, the occurrence of antibiotics in aquatic environment is posing an ecological health concern.^

The Argentine Dilemma: “Vulture Funds” and the Risks Posed to Developing Economies

Post-crisis Argentina is a case study of crisis management through debt restructuring. This article examines how Argentina negotiated the external debt in the wake of the sovereign default in December 2001 and now confronts challenges posed by holdout creditors—the so called “vulture funds”. It argues that debt restructuring has put a straitjacket on the national economy, making it virtually impossible for healthy growth short of a break with the international economic order. While Argentina has successfully restructured a $95 billion debt with an unprecedented “hair cut” (around 70% reduction in “net value of debt”), a sustainable growth appears out of reach as long as reliance on the government debt market prevails. In this cycle, the transmission belt of financial crisis to developing countries is characterized by the entry of highly speculative players such as hedge funds, conflicts of interests embedded in “sovereign debt restructuring” (SDR) and vulnerabilities associated with “emerging market debt”.

Taking risks in the face of uncertainty:an exploratory analysis of green innovation

The relationship between uncertainty and firms’ risk-taking behaviour has been a focus of investigation since early discussion of the nature of enterprise activity. Here, we focus on how firms’ perceptions of environmental uncertainty and their perceptions of the risks involved impact on their willingness to undertake green innovation. Analysis is based on a cross-sectional survey of UK food companies undertaken in 2008. The results reinforce the relationship between perceived environmental uncertainty and perceived innovation risk and emphasise the importance of macro-uncertainty in shaping firms’ willingness to undertake green innovation. The perceived (market-related) riskiness of innovation also positively influences the probability of innovating, suggesting either a proactive approach to stimulating market disruption or an opportunistic approach to innovation leadership.

Measuring Tail Risks at High Frequency

I develop a new methodology for measuring tail risks using the cross section of bid-ask spreads. Market makers embed tail risk information into spreads because (1) they lose to arbitrageurs when changes to asset values exceed the cost of liquidity and (2) underlying price movements and potential costs are linear in factor loadings. Using this insight, simple cross-sectional regressions relating spreads and trading volume to factor betas can recover tail risks in real time for priced or non-priced return factors. The methodology disentangles financial and aggregate market risks during the 2007-2008 Financial Crisis; anticipates jump risks associated with Federal Open Market Committee announcements; and quantifies a sharp, temporary increase in market tail risk before and throughout the 2010 Flash Crash. The recovered time series of implied market risks also aligns closely with both realized market jumps and the VIX.

Summary and Risks of ABS Transactions Under EU and US Law

This chapter examines the legal concept of summary in terms of its potential legal liability and other types of risks under EU and US disclosure laws.

Social Skills Training in Flight Schools: A Proactive Tool for Management of Threats and Risks

Safety Management Systems in aviation generate training programs that develop skills needed to perform safety functions. The objective of this study is to show that, in groups, individuals need to have interpersonal skills and, in particular, ability to communicate with others, to listen, and to influence. It is for this reason that Social Skills Training is important in Aviation. Professionals trained in social skills are more likely to identify threats and risks caused by interpersonal situations, be assertive, and take appropriate action. As a contribution, this paper suggests a set of policies, procedures and practices for educating and training future professionals who will work in aviation safety.

Influences, risks and prospects of city development on urban drainage systems

Christian Mikovits

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013

Global, regional, and national comparative risk assessment of 79 behavioral, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015 : a systematic analysis for the Global Burden of Disease Study 2015

Do breech presentations in twins and singletons run different risks?

SCOPUS: no.j

Cities at risk: status of Italian planning system in reducing seismic and hydrological risks

Italy and its urban systems are under high seismic and hydrogeological risks. The awareness about the role of human activities in the genesis of disasters is achieved in the scientific debate, as well as the role of urban and regional planning in reducing risks. The paper reviews the state of Italian major cities referred to hydrogeological and seismic risk by: 1) extrapolating data and maps about seismic hazard and landslide risk concerning cities with more than 50.000 inhabitants and metropolitan contexts, and 2) outlining how risk reduction is framed in Italian planning system (at national and regional levels). The analyses of available data and the review of the normative framework highlight the existing gaps in addressing risk reduction: nevertheless a wide knowledge about natural risks afflicting Italian territory and an articulated regulatory framework, the available data about risks are not exhaustive, and risk reduction policies and multidisciplinary pro-active approaches are only partially fostered and applied.