An assessment of the performance of municipal constructed wetlands in Ireland.

While performance assessments of constructed wetlands sites around the world have appraised their capacity for effective removal of organics, a large variance remains in these sites' reported ability to retain nutrients, which appears to depend on differences in design, operation and climate factors. Nutrient retention is a very important objective for constructed wetlands, to avoid eutrophication of aquatic environments receiving their effluents. This study assessed the performance of constructed wetlands in terms of nutrient retention and associated parameters under the humid conditions of Ireland's temperate maritime climate. A review of the performance of 52 constructed wetland sites from 17 local authorities aimed to identify the best performing types of constructed wetlands and the treatment factors determining successful compliance with environmental standards. Data analysis compared effluent results from constructed wetlands with secondary free surface flow or tertiary horizontal subsurface flow, hybrid systems and integrated constructed wetlands with those from small-scale mechanical wastewater treatment plants of the same size class. Nutrient concentrations in effluents of constructed wetlands were negatively correlated (p < .01) with specific area, i.e. the ratio of surface area and population equivalents. The latest generation of integrated constructed wetlands, which had applied design guidelines issued by the Department of the Environment, performed best. Storm management design features improved treatment performance of constructed wetlands significantly (p < .05) for total suspended solids concentrations and exceedance frequency of limit values for total nitrogen. Mechanical wastewater treatment plants, secondary free surface water and tertiary horizontal subsurface flow wetlands showed a very large variance in effluent concentrations for organic and nutrient parameters. E. coli numbers in effluents were lowest for integrated constructed wetlands with an arithmetic mean of 89 MPN/100 ml. Despite Ireland's humid climate, some constructed wetland sites achieved long or frequent periods of zero effluent discharge and thus did not transfer any waterborne pollution to their receptors during these periods.

Path integral Monte Carlo on a lattice. II. Bound states.

The equilibrium properties of a single quantum particle (qp) interacting with a classical gas for a wide range of temperatures that explore the system's behavior in the classical as well as in the quantum regime is investigated. Both the qp and the atoms are restricted to sites on a one-dimensional lattice. A path integral formalism developed within the context of the canonical ensemble is utilized, where the qp is represented by a closed, variable-step random walk on the lattice. Monte Carlo methods are employed to determine the system's properties. To test the usefulness of the path integral formalism, the Metropolis algorithm is employed to determine the equilibrium properties of the qp in the context of a square well potential, forcing the qp to occupy bound states. We consider a one-dimensional square well potential where all atoms on the lattice are occupied with one atom with an on-site potential except for a contiguous set of sites of various lengths centered at the middle of the lattice. Comparison of the potential energy, the energy fluctuations, and the correlation function are made between the results of the Monte Carlo simulations and the numerical calculations.

The European Cancer Observatory: A new data resource.

Population-based cancer registries provide indispensable information on cancer incidence and survival, which cannot be obtained by any other means. It is clear that complete and effective use of these data is essential for cancer control, but sharing this information in a uniform, timely and user-friendly manner has been somewhat limited up to now. The European Cancer Observatory (ECO, http://eco.iarc.fr) has been developed in the framework of the EUROCOURSE project (EUROpe against Cancer: Optimisation of Use of Registries for Scientific Excellence in Research) as a comprehensive resource combining all the information currently available in Europe on cancer incidence, mortality, survival and prevalence. The website provides analytical and presentation tools to examine national estimates for 2012 in 40 European countries (EUCAN), data for 130 national or sub-national areas covered by cancer registries for up to 60 years, until 2011 (EUREG) and a planned mechanism for data download (European Cancer Incidence and Mortality (EUROCIM)). The generated statistics outline the considerable variability across Europe in the rates of all major cancer types and help identify key concerns that need to be addressed by public health policies e.g. the unprecedented rise of lung cancer incidence in women with its full impact expected within a decade or so. The support, maintenance and further development of the ECO website should be a high priority for European cancer policymakers, to continue providing this unique information to health professionals, researchers and the general public in Europe and beyond.

Path integral Monte Carlo on a lattice: extended states.

The equilibrium properties of a single quantum particle (qp) interacting with a classical gas for a wide range of temperatures that explore the system's behavior in the classical as well as in the quantum regime is investigated. Both the qp and atoms are restricted to the sites of a one-dimensional lattice. A path integral formalism is developed within the context of the canonical ensemble in which the qp is represented by a closed, variable-step random walk on the lattice. Monte Carlo methods are employed to determine the system's properties. For the case of a free particle, analytical expressions for the energy, its fluctuations, and the qp-qp correlation function are derived and compared with the Monte Carlo simulations. To test the usefulness of the path integral formalism, the Metropolis algorithm is employed to determine the equilibrium properties of the qp for a periodic interaction potential, forcing the qp to occupy extended states. We consider a striped potential in one dimension, where every other lattice site is occupied by an atom with potential ε, and every other lattice site is empty. This potential serves as a stress test for the path integral formalism because of its rapid site-to-site variation. An analytical solution was determined in this case by utilizing Bloch's theorem due to the periodicity of the potential. Comparisons of the potential energy, the total energy, the energy fluctuations, and the correlation function are made between the results of the Monte Carlo simulations and the analytical calculations.

Prospective evaluation of the role of atherosclerosis on cerebral atrophy: pilot study.

PURPOSE: Our purpose was to study the association between atherosclerosis measured by arterial calcium on computed tomography (CT) and cerebral atrophy demonstrated by brain magnetic resonance imaging (MRI). MATERIALS AND METHODS: IRB approved this prospective study. Twenty-one consecutive patients with acute stroke-like symptoms who are scheduled to have brain MRI were recruited on a voluntary basis. electrocardiogram (ECG)-gated helical CT scans were used to determine the arterial calcium as a reliable index of underlying atherosclerosis. Extracranial arterial calcium content was measured quantitatively by special software available in our CT scanner. Intracranial calcium was graded qualitatively. Brain MRI was independently evaluated to identify cortical, central atrophy, and ischemic changes. Relationship between CT demonstrated atherosclerosis and cerebral ischemic changes, brain atrophy patterns were evaluated both without and with adjustment for age and hypertension. RESULTS: Out of 21 patients 20 were included in final study group. There was no correlation between atherosclerotic calcium measures and cortical atrophy, ischemic findings. Both intracranial and extracranial atherosclerosis had partial correlation with central atrophy (R= 0.43 and 0.52, respectively). After adjustment for age, only intracranial atherosclerosis maintained a partial correlation with central atrophy (R= 0.41). However, this correlation did not reach a statistically significant level (P= .10). CONCLUSIONS: Intracranial atherosclerosis demonstrated a possible correlation with central atrophy.

Unusual case of 2 renal cell carcinoma metastases ipsilateral to an occluded internal carotid artery.

Hemodynamic factors may play a role in the seeding and subsequent growth of cerebral metastasis. The authors present a case with 2 foci of cerebral metastasis in the same vascular territory ipsilateral to an occluded internal carotid artery. A 65-year-old man with chronic left frontal lobe infarct and left internal carotid artery occlusion was diagnosed with 2 large hemorrhagic metastases in the left middle cerebral artery territory. Diminished flow signals were seen in the trunk and branches of the left middle cerebral artery on magnetic resonance angiography. This case illustrates preferential seeding and growth of cerebral metastases in a region of the brain with diminished blood flow.

Nerve atrophy in severe trigeminal neuralgia: noninvasive confirmation at MR imaging--initial experience.

PURPOSE: To retrospectively evaluate the size of the trigeminal nerve on magnetic resonance (MR) images of patients with unilateral trigeminal neuralgia. MATERIALS AND METHODS: Institutional review board approval was obtained and informed consent was waived for this HIPAA-compliant study. The sizes of the trigeminal nerves in 31 patients (18 men and 13 women; mean age, 68 years; age range, 44-84 years) with clinically confirmed intractable unilateral trigeminal neuralgia were measured before treatment with gamma knife radiosurgery. Images were analyzed separately by two neuroradiologists who were blinded to the side of the face with symptoms. Coronal projection images were used to determine the diameter and cross-sectional area of the trigeminal nerves at 5 mm from the entry point of the nerve into the pons. Comparisons were made by using a paired t test. Interobserver variability was assessed by using the Pearson correlation coefficient. RESULTS: The mean diameter of the trigeminal nerve on the symptomatic side was significantly smaller than the mean diameter on the asymptomatic side in 30 of 31 patients (2.11 mm +/- 0.40 [standard deviation] and 2.62 mm +/- 0.56, P < .001, 95% confidence interval: -0.35, -0.67 mm). The mean cross-sectional area on the symptomatic side was significantly smaller than the area on the asymptomatic side in 27 of 31 patients (4.50 mm(2) +/- 1.75 and 6.28 mm(2) +/- 2.19, P < .001, 95% confidence interval: -2.41, -1.16 mm(2)). CONCLUSION: The results indicate that trigeminal nerve atrophy can be depicted noninvasively in patients with trigeminal neuralgia.

Association between neurovascular contact on MRI and response to gamma knife radiosurgery in trigeminal neuralgia.

Treatment with gamma knife radiosurgery (GKRS) provides adequate short-term pain control in about 70% of the patients with intractable trigeminal neuralgia (TN). The purpose of our study was to evaluate whether the presence of neurovascular contact (NVC) at the root entry zone of the trigeminal nerve on pre-gamma knife MR imaging predicts an increased likelihood of an adequate response to GKRS. We studied 40 consecutive patients who underwent GKRS for treatment of intractable TN. Two neuroradiologists blinded to the side of symptoms analyzed pre-treatment constructive interference in steady state (CISS) images to determine the presence of NVC by consensus. An adequate response was defined as freedom from pain with or without reduced need for medical therapy. Adequate short-term response to GKRS was seen in 29 (72.5%) of 40 patients. NVC was seen in 30 of the 40 patients. Twenty-five (83.3%) of 30 patients with NVC had adequate short-term response to GKRS. Only four (40%) of the 10 patients without NVC had adequate response to GKRS (X2=7.06; P<0.01). Patients with NVC were seven times more likely to have an adequate response to GKRS than those without NVC (odds ratio =7.5).The presence of NVC on pre-treatment MR imaging predicts an increased likelihood of an adequate response to GKRS.

Magnetic resonance imaging of the cervix during pregnancy: effect of gestational age and prior vaginal birth.

OBJECTIVE: To investigate how gestational age and prior vaginal birth affect cervical anatomy on magnetic resonance imaging during pregnancy. STUDY DESIGN: Magnetic resonance images of the cervix were obtained in consecutive patients referred for a suspected fetal abnormality. We used an image processing protocol to measure cervical dimensions, orientation, and signal intensity. We determined how outcome variables were affected by gestational age and prior vaginal birth. RESULTS: Adequate images were obtained in 53 of 57 patients at 17 to 36 weeks. As gestational age increased by 12 weeks, the mean cross-sectional area of the cervical canal and cervical stroma increased 31% (95% confidence interval 0% to 73%) and 31% (95% confidence interval 11% to 55%), respectively. The normalized signal intensity of the stroma increased from 0.83 (95% confidence interval 0.81 to 0.85) at 20 weeks to 0.91 (95% confidence interval 0.88 to 0.94) at 32 weeks. None of the outcome variables were affected by prior vaginal birth. CONCLUSION: Magnetic resonance imaging revealed that cross-sectional area and signal intensity of the cervical stroma increase with increasing gestational age.

Rhabdomyoma of the head and neck demonstrated by prenatal magnetic resonance imaging.

A case of fetal rhabdomyoma (myxoid type) of the head and neck demonstrated on prenatal magnetic resonance imaging (MRI) is presented. This benign tumor of skeletal muscle is uncommon and should not be confused with its malignant counterpart-rhabdomyosarcoma. With the increasing use of ultrafast MRI, the radiologist is more likely to encounter head and neck masses in the fetus.