Microwave Lens for Polar Molecules

We here report on the implementation of a microwave lens for neutral polar molecules suitable to focus molecules both in low-field-seeking and in high-field-seeking states. By using the TE_11m modes of a 12 cm long cylindrically symmetric microwave resonator, Stark-decelerated ammonia molecules are transversally confined. We investigate the focusing properties of this microwave lens as a function of the molecules' velocity, the detuning of the microwave frequency from the molecular resonance frequency, and the microwave power. Such a microwave lens can be seen as a first important step towards further microwave devices, such as decelerators and traps.Comment: 4 pages, 3 figure

Anharmonic magnetic deformation of self-assembled molecular nanocapsules

High magnetic fields were used to deform spherical nanocapsules, self-assembled from bola-amphiphilic sexithiophene molecules. At low fields the deformation -- measured through linear birefringence -- scales quadratically with the capsule radius and with the magnetic field strength. These data confirm a long standing theoretical prediction (W. Helfrich, Phys. Lett. {\bf 43A}, 409 (1973)), and permits the determination of the bending rigidity of the capsules as (2.6$\pm$0.8)$\times 10^{-21}$ J. At high fields, an enhanced rigidity is found which cannot be explained within the Helfrich model. We propose a complete form of the free energy functional that accounts for this behaviour, and allows discussion of the formation and stability of nanocapsules in solution.Comment: 4 pages, 3 figures, accepted in Phys. Rev. Let

Socially defeated male rats display a blunted adrenocortical response to a low dose of 8-OH-DPAT

The study examined in male Wistar rats the influence of social defeat on the neuroendocrine stress response system using injection of the 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), as the pharmacological challenge. Social defeat was defined by the submissive postures displayed by the Wistar rats which were threatened and attacked by Tryon Maze Dull S3 rats for 10 min. 18-20 h after social defeat, the defeated rats were injected intravenously (i.v.) with a low and high dose of 8-OH-DPAT in their home cages. Blood samples were withdrawn from the freely moving cannulated rats for determination of plasma corticosterone and catecholamines. The corticosterone response to the low dose of 8-OH-DPAT (0.05 mg/kg, i.v.) was significantly diminished in the defeated rats as compared to the controls, but this dose failed to affect catecholamine concentrations. The high dose of 8-OH-DPAT (0.15 mg/kg, i.v.) significantly elevated corticosterone and adrenaline levels in defeated and control rats to the same extent, whereas no effect on noradrenaline was found. The present data thus indicate that social defeat blunts 5-HT1A receptor-mediated adrenocortical activation probably via a decrease in the sensitivity of a population of postsynaptic 5-HT receptors

Comparison of Conventional and Nonconventional Hydrogen Bond Donors in Au^- Complexes

Although gold has become a well-known nonconventional hydrogen bond acceptor, interactions with nonconventional hydrogen bond donors have been largely overlooked. In order to provide a better understanding of these interactions, two conventional hydrogen bonding molecules (3-hydroxytetrahydrofuran and alaninol) and two nonconventional hydrogen bonding molecules (fenchone and menthone) were selected to form gas-phase complexes with Au-. The Au-[M] complexes were investigated using anion photoelectron spectroscopy and density functional theory. Au-[fenchone], Au-[menthone], Au-[3-hydroxyTHF], and Au-[alaninol] were found to have vertical detachment energies of 2.71 ± 0.05, 2.76 ± 0.05, 3.01 ± 0.03, and 3.02 ± 0.03 eV, respectively, which agree well with theory. The photoelectron spectra of the complexes resemble the spectrum of Au- but are blueshifted due to the electron transfer from Au- to M. With density functional theory, natural bond orbital analysis, and atoms-in-molecules analysis, we were able to extend our comparison of conventional and nonconventional hydrogen bonding to include geometric and electronic similarities. In Au-[3-hydroxyTHF] and Au-[alaninol], the hydrogen bonding comprised of Au-···HO as a strong, primary hydrogen bond, with secondary stabilization by weaker Au-···HN or Au-···HC hydrogen bonds. Interestingly, the Au-···HC bonds in Au-[fenchone] and Au-[menthone] can be characterized as hydrogen bonds, despite their classification as nonconventional hydrogen bond donors

The Use of Transport Time Scales as Indicators of Pollution Persistence in a Macro-Tidal Setting

An understanding of water exchange processes is essential for assessing water quality management issues in coastal bays. This paper evaluates the impact of water exchange processes on pollution persistence in a macro-tidal semi-closed coastal bay through two transport time scales (TTS), namely residence time and exposure time. The numerical model was calibrated against field-measured data for various tidal conditions. Simulated current speeds and directions were shown to agree well with the field data. By considering different release scenarios of a conservative tracer by the refinement of an integrated hydrodynamic and solute transport model (the EFDC), the two TTS were used for interpreting the water exchange processes in a semi-closed system, and for describing the effects of advective and dispersive processes on the transport and fate of pollutants. The results indicate that the magnitudes of river inflows to the bay, tidal ranges, and tracer release times significantly influence the residence and exposure times. Return coefficients were shown to be variable, confirming the different effects of returning water for the different conditions that were studied. For the tested river flow magnitudes and tide conditions, the exposure times were generally higher than the residence times, but particularly so for neap tide conditions. The results, therefore, highlight the risks associated with pollutants leaving a specified domain on an outgoing tide but re-entering on subsequent incoming tides. The spatial distributions of the exposure and residence times across the model domain confirmed that for the case of Dublin Bay, river inputs have a potentially greater impact on water quality on the northern side of the bay

Evaluating a Microbial Water Quality Prediction Model for Beach Management Under the Revised EU Bathing Water Directive

The revised Bathing Water Directive (2006/7/EC) requires EU member states to minimise the risk to public health from faecal pollution at bathing waters through improved monitoring and management approaches. While increasingly sophisticated measurement methods (such as microbial source tracking) assist in the management of bathing water resources, the use of deterministic predictive models for this purpose, while having the potential to provide decision making support, remains less common. This study explores an integrated, deterministic catchment-coastal hydro-environmental model as a decision-making tool for beach management which, based on advance predictions of bathing water quality, can inform beach managers on appropriate management actions (to prohibit bathing or advise the public not to bathe) in the event of a poor water quality forecast. The model provides a ‘moving window’ five-day forecast of Escherichia coli levels at a bathing water compliance point off the Irish coast and the accuracy of bathing water management decisions were investigated for model predictions under two scenarios over the period from the 11th August to the 5th September, 2012. Decisions for Scenario 1 were based on model predictions where rainfall forecasts from a meteorological source (www.yr.no) were used to drive the rainfall–runoff processes in the catchment component of the model, and for Scenario 2, were based on predictions that were improved by incorporating real-time rainfall data from a sensor network within the catchment into the forecasted meteorological input data. The accuracy of the model in the decision-making process was assessed using the contingency table and its metrics. The predictive model gave reasonable outputs to support appropriate decision making for public health protection. Scenario 1 provided real-time predictions that, on 77% of instances during the study period where both predicted and E. coli concentrations were available, would correctly inform a beach manager to either take action to mitigate for poor bathing water quality or take no action. However, Scenario 1 also provided data to support a decision to take action (when none was necessary – a type I error) in 4% of instances and to take no action (when action was required – a type II error) in 19% of the instances analysed. Type II errors are critical in terms of public health protection given that for this error, bathers can be exposed to risks from poor bathing water quality. Scenario 2, on the other hand, provided predictions that would support correct management actions for 79% of the instances but would result in type I and type II errors for 4% and 17% of the instances respectively. Comparison of Scenarios 1 and 2 for this study indicate that Scenario 2 gave a marginally better overall performance in terms of supporting correct management decisions, as it provided data that could result in a lower occurrence of the more critical type II errors. Given that the 28 member states of the European Union are required to engage with the public health provisions of the revised Bathing Water Directive, issues of compliance, pertaining particularly to the management of bathing water resources, remain topical. Decision supports for managing bathing waters in the context of the Directive are likely to become the focus of much attention and although, the current study has been validated in bathing waters off the east coast of Ireland, the approach of using a deterministic and integrated catchment-coastal model for such purposes is easily transferable to other bathing water jurisdictions

Hydro-Environmental Modeling of Sewage and Riverine Discharges into a Coastal Area: Comparison of Depth-averaged and Three-Dimensional Models

This study applies and compares two hydrodynamic and water quality models; a depth-averaged (TELEMAC-2D) and a three-dimensional model (TELEMAC-3D) on their performance in simulating the transport and fate of Escherichia coli (a main microbial bathing water quality indicator) in the coastal waters of Bray, Ireland subjected to sewage discharges and freshwater inflows from the River Dargle. The models first calibrated and validated against hydrodynamic and water quality data, were used to simulate Escherichia coli distribution patterns based on mean spring and mean neap tides for dry and wet weather scenarios. The hydrodynamic calibration yielded a good match between both models (TELEMAC-2D and TELEMAC-3D) and measured velocities. The E. coli model calibrations showed that TELEMAC-2D resulted in a lower value for decay rate (higher T90 value) than TELEMAC-3D in order to match the measured E. coli concentrations. E. coli surface distributions at the time of HW resulted in TELEMAC-2D plumes that were lesser in extent and concentrations than those of TELEMAC-3D due to the fact that depth-averaged hydrodynamics underestimate the surface water velocity resulting in lower concentrations of E. coli at the water surface compared to TELEMAC-3D. The wet weather scenarios of both TELEMAC-2D and TELEMAC-3D exhibited high E. coli concentrations at the water surface that exceed the “Sufficient” limit of the Bathing Water Directive, the latter finding highlights the need for including Ultra Violet disinfection in the treatment process at Shanganagh Sewage Treatment Work

Imaging-documented repeated intratumoral hemorrhage in vestibular schwannoma: a case report

Intratumoral hemorrhage in vestibular schwannomas is rare. Symptoms often have an acute onset and include headache, nausea, vomiting, vertigo, and depressed consciousness. Intratumoral hemorrhage is probably caused by vascular fragility associated with tumor characteristics and growth. With hemorrhage in VS being rare, repeated hemorrhage has only been reported twice, and on clinical grounds only. The present report details the case of acute neurological deterioration in a patient with repeated intratumoral hemorrhage inside a vestibular schwannoma with computed tomography and magnetic resonance imaging confirmation. To our knowledge, repeated hemorrhage in vestibular schwannoma with radiological confirmation has not been reported before

Bathing Water Quality Prediction Using an Integrated Catchment and 3-D Coastal Hydrodynamic Model

Under the new European Union Bathing Water Directive (2006/7/EC) which comes into force in 2014, more stringent bathing water quality standards, defined in terms of Escherichia coli (E.coli) and Intestinal Enterococci (I.E.), will apply in Irish bathing waters. Compliance with these standards is ensured through a structured water quality monitoring programme that is published by Authorities with responsibility for bathing water areas in advance of each bathing season. The directive recognises that elevated levels of faecal coliform bacteria in bathing areas can derive from the overland transport of waste from livestock in the rural fraction of river catchments. On days therefore, that follow significant storm events in coastal agricultural catchments, exceedences of threshold bacteria levels may occur. Given that these exceedences result from ‘natural’ rather than anthropogenic influences, a ‘discounting’ mechanism that allows for a temporary relaxation of these standards is allowed for short-term pollution incidents. In this regard, some high levels of faecal bacteria contamination can be excluded from the water quality record. However, this ‘discounting’ is only permitted if elevated bacterial levels are predicted in advance and mitigation actions to maintain public health protection are taken. This paper presents an integrated catchment (MIKE11) and 3-dimensional coastal (MIKE3) modelling tool for predicting the bathing water quality at Bray, Co. Wicklow. Models were calibrated using flow and water quality data. Adjustment of the M2 and S2 tidal constituents of the MIKE global model has resulted in an improved fit to measured water levels at the five reference tidal gauges. Bottom friction was calibrated to produce good correlations of measured and simulated current speed and direction. Furthermore, results of the water quality transport model has shown that the model has adequately replicated measurements of E.coli and IE