Enumeration, variability, and transport of Escherichia coli in the foreshore reservoir and surface water at freshwater beaches

Beaches are of immense recreational, societal and economic value. This value, however, is considerably diminished by poor water quality. Fecal indicator bacteria (FIB) are measured at recreational beaches worldwide to assess the water quality. A beach closure or advisory is issued if FIB concentrations in surface water exceed recreational water quality standards. Due to the lengthy time required to enumerate FIB (24 – 96 hours), statistical and mechanistic models have been developed to predict water quality exceedances a priori and to better understand why and under what conditions water quality exceedances occur. These models as well as beach water quality management strategies are often based on limited mechanistic understanding of the fate and transport of FIB in the beach environment. For instance, FIB are known to accumulate at very high concentrations in foreshore sand and porewater at beaches (herein referred to as the foreshore reservoir). The dynamics of FIB accumulation in the foreshore reservoir and its subsequent release, including the impact on surface water quality exceedances, is unknown. It is also unclear how to best quantify the abundance of FIB in the reservoir including its partitioning between the sand and pore water. An increased understanding of the behavior of FIB at beaches is needed to improve the accuracy of predictive water quality models, develop effective measures to reduce water quality exceedances, improve water quality monitoring strategies, and ultimately to better protect human health at recreational beaches. This thesis focuses on addressing key knowledge gaps regarding the behavior and quantification of FIB in the foreshore reservoir. In the first study, seasonal and daily variabilities in FIB concentrations in the foreshore reservoir and surface water are evaluated including determining the influence of environmental factors, such as temperature, waves, and rainfall. In this study, seasonal variability in FIB concentrations in the surface water and foreshore reservoir were found to depend on environmental factors, with some beaches showing a gradual increasing trend through the summer, then decreasing towards the beginning of fall. However, daily variation showed that FIB variability is much more complex and FIB may not simply accumulate over the summer months as previously thought. Further, this study showed for the first time that FIB may be able to replicate in unseeded natural foreshore beach sand not subjected to external stimuli. The second study uses experimental and field data to evaluate the behavior of FIB in the beach environment during intensified wave conditions including the transfer of FIB from the foreshore reservoir to the surface water. This study showed that as wave height increased foreshore sand erosion resulted in elevated E. coli concentrations in surface water, as well as depletion of E. coli from the foreshore sand and pore water. E. coli initially attached to foreshore sand rather than initially residing in the pore water was found to be the main contributor to elevated surface water concentrations. Surface water E. coli concentrations were a function of not only wave height (and associated sand erosion) but also the time elapsed since a preceding period of high wave intensity. This finding is important for statistical regression models used to predict beach advisories. While calculations suggested that foreshore sand erosion may be the dominant mechanism for releasing E. coli to surface water during intensified wave conditions at a fine sand beach, comparative characterization of the E. coli distribution at a coarse sand-cobble beach suggested that interstitial pore water flow and discharge may be more important for coarser sand beaches. The third study compared the partitioning of FIB in the foreshore reservoir between the sand and pore water and evaluated different sampling methods for quantifying FIB in the foreshore reservoir at beaches with varying grain sizes. This study showed that the collection of the top 1 cm of unsaturated sand resulted in higher and more variable concentrations than the top 5 cm of sand. There were no statistical differences in E. coli concentrations when using different methods to sample the saturated sand. Overall, the unsaturated sand had the highest amount of E. coli when compared to saturated sand and pore water (considered on a bulk volumetric basis). Pore water sampled with a shovel resulted in the highest observed E. coli concentrations (only statistically significant at fine sand beaches) and lowest variability compared to other sampling methods. These findings presented will help determine the appropriate sampling strategy for characterizing FIB abundance in the foreshore reservoir as a means of predicting its potential impact on nearshore surface water quality and public health risk. Overall, this thesis presents valuable information to health departments, beach managers, and scientists interested in improving water quality and water quality predictions at recreational beaches. Findings from this thesis increase understanding of FIB behavior, especially in the foreshore reservoir, and can be used to improve predictive water quality models, develop strategies to reduce FIB levels at beaches, and identify where and when a foreshore reservoir may be an important source of FIB to the surface water at a beach

The decline of Fowler\u27s Toad (Bufo fowleri) in southern Louisiana: molecular genetics, field experiments and landscape studies

Two of the most pervasive threats to species biodiversity are invasive species and habitat loss and degradation. Invasive species are often relatively insensitive to disturbance and many expand their range into disturbed and fragmented habitats. This dissertation uses an interdisciplinary approach to investigate how anthropogenic habitat disturbance is precipitating a range expansion in an invasive toad species, Bufo nebulifer, which is driving a decline in its native congener, B. fowleri. I employed a remote sensing and GIS study using historical data to compare changes in the two species distributions and habitat changes, a molecular genetic study to identify interspecific hybrids and their potential effects on the parental species, and an experimental ecology study to look at the effects of competition and predation on the two species. The results of the landscape level analyses of species\u27 distributional changes in different disturbance levels showed that both species\u27 distributions have changed significantly. The distributions of the two species are inversely affected by habitat disturbance; the distribution of B. fowleri in highly degraded habitat has contracted while the expansion of B. nebulifer increased substantially. The molecular genetic study successfully demonstrated the use of nuclear and mitochondrial markers to identify cryptic hybrids and their maternal lineage. Three hybrids were detected using nuclear introns and a morphologically cryptic hybrid was identified using mitochondrial DNA as the progeny of a cross that was previously thought to be inviable. Although relatively few hybrids were currently found, the identification of a cryptic hybrid implies that the rate of historical hybridization may have been drastically underestimated. Ecological studies showed that competition with B. nebulifer tadpoles had a negative effect on both body size measures and survival to metamorphosis for B. fowleri tadpoles. The addition of predators to experiment did not favor the survival of B. fowleri over B. nebulifer. Bufo fowleri\u27s inability to compete with its invasive congener could be a driving mechanism for the decline of B. fowleri and the expansion of B. nebulifer. The methods discussed in this dissertation offer promising and practical new approaches for evaluating and managing changes in the distribution of species of conservation concern

Obama nach seinem einjährigen Amtsjubiläum : Der Hoffnungsträger im Realitäts-Check

Der frische Wind, den US-Präsident Barack Obama in der amerikanischen Politik versprach, scheint sich gut ein Jahr nach seinem Amtsantritt in der verstaubten Routine des Washingtoner Politzirkus verloren zu haben. Die Euphoriewelle, auf der Obama zu seinem Amtsantritt schwamm, ist langsam verebbt und die amerikanische Politik dümpelt in altbekanntem Prozedere zwischen der Exekutive im Weißen Haus und den zwei Kammern des Kapitols vor sich hin. Die Desillusionierung der amerikanischen Bevölkerung zeigt sich in den fallenden Umfragewerten der Regierung Obama, die inzwischen unter das Niveau des Wahltages 2008 gesunken sind. Und auch in Europa, wo man sich einen Politikwandel vom neuen amerikanischen Präsidenten versprach, tritt langsam Ernüchterung ein

Palatalization in Romanian — Acoustic properties and perception

This paper presents the results of an acoustic study of fricatives from four places of articulation produced by 31 native speakers of Romanian, as well as those of a perceptual study using the stimuli from the acoustic experiment, allowing for a direct comparison between acoustic properties and perception. It was found that there are greater acoustic differences between plain and palatalized labials and dorsals as compared to coronals. The acoustic results were paralleled by the perceptual findings. This pattern departs from cross-linguistic generalizations made with respect to the properties of secondary palatalization. A likely source of the differences is the fact that previous studies of secondary palatalization typically involved stops which tend to exhibit various enhancement phenomena at the coronal place of articulation. Since the enhancement generally involves additional frication, this is not a useful strategy for fricatives at the coronal, or any other place of articulation. These findings form the basis of a discussion highlighting the differences between enhanced and non-enhanced secondary palatalization

Aged B lymphocytes retain their ability to express surface markers but are dysfunctional in their proliferative capability during early activation events

Abstract Background Ageing is associated with dysfunction in the humoral response leading to decreased protection against infectious diseases. Defects in T cell function due to age have been well characterized but it is unclear if dysfunctions in antibody responses are due to deficiencies in a helper environment or intrinsic B cell defects. Previous studies from our laboratory have shown that aged B lymphocytes are able to differentiate into high affinity antibody-secreting cells at a frequency similar to their young counterparts. However, expansion of B cells in vivo was reduced in aged animals when compared to young. Methods To further investigate the cause of this reduced expansion, we have now examined early activation events of aged B cells in response to anti-CD40 monoclonal antibody (mAb) and lipopolysaccharide (LPS) stimulation in vitro. To do this spleen cells were harvested from young, middle-aged and aged quasi-monoclonal (QM) mice and cultured in complete RPMI for 24 and 48 hours. Cultures contained either LPS or anti-CD40 mAb and murine IL-4. Cells were collected and analyzed using flow cytometry. To examine the proliferative capacity of aged B cells spleen cells were collected as before and cultured in 96 well microtiter plates with either LPS or anti-CD40 mAb and murine IL-4 for 24 hours. Tritiated thymidine ([3H]-Tdr) was added to each well and incubated for another 24 hours after which cells were collected and analyzed using a scintillation counter. Results Resting aged B cells exhibited similar levels of CD40 expression when compared to young cells and efficiently up-regulated CD86 and CD69 and also down-regulated CD38 upon stimulation. However, aged B cells proliferated less than young B cells and showed a consistent, but not statistically significant, reduction in their ability to form blast cells. Conclusion Aged B cells exhibited a reduced response in some early activation events but produced at least a partial response in all cases. Thus, therapeutic intervention may be possible, despite intrinsically different responses in aged B cells.</p

William Ritter et le wagnérisme : "Ægyptiacque", une « paraphrase wagnérienne » ?

Cet article se propose d’étudier les formes et les limites du wagnérisme dans Ægyptiacque, le premier roman publié par William Ritter, en se concentrant sur les deux personnages principaux. Si les références aux drames wagnériens sont essentielles, elles se doublent de renvois à des figures mythologiques diverses. Ritter reformule aussi la conception wagnérienne de l’amour pour qu’elle corresponde à ses convictions personnelles. Nous commencerons par définir brièvement l’esthétique wagnérienne, avant de présenter le wagnérisme littéraire en France, et de préciser la posture de Ritter dans ce contexte. Enfin, nous examinerons les personnages du roman et terminerons en analysant la manière dont Ritter condamne la vision wagnérienne de l’amour pour proposer, à sa place, un autre idéal amoureux. Keywords: Ritter, Wagner, wagnérisme, figures mythologiques, reconfiguratio

A Place for the Church within Professional Psychology

There are various reasons why Christian psychologists may resist fully participating in a church community. Among these are historic tensions between science and religion, the complexity of multiple role relationships, cynicism related to clients\u27 negative experiences in religious communities, and differing perspectives on attributions and human nature. Despite these obstacles, there are compelling reasons for psychologists to remain involved in church. Eight of these reasons are described--clustered into professional, relational, and transformational domains--and implications discussed

Microtubular Gas Diffusion Electrode Based on Ruthenium-Carbon Nanotubes for Ambient Electrochemical Nitrogen Reduction to Ammonia

The drawback of the energy-intensive Haber-Bosch process promotes the research and development of alternative ammonia (NH3) synthesis approaches. The electrochemical nitrogen (N2) reduction reaction (eNRR) may offer a promising method to produce NH3 independent of fossil-fuel-based hydrogen production. However, the low solubility and the low-efficiency mass transport of N2 in aqueous electrolytes are still among the challenges facing the feasibility of eNRR. Herein, we demonstrate a microtubular ruthenium-carbon nanotube gas diffusion electrode (Ru−CNT GDE), for the first time, applying it to electrochemical NH3 synthesis in an H-type cell under ambient conditions. The highest reported Ru-catalyzed NH3 yield rate of 2.1×10−9 mol/cm2 s and high faradaic efficiency of 13.5 % were achieved, showing the superior effect of Ru−CNT GDEs on the eNRR performance. This work provides a new approach for the design and fabrication of self-standing catalyst-loaded GDEs for eNRR. © 2020 The Authors. ChemElectroChem published by Wiley-VCH Gmb

A non-pharmacologic approach to address challenging behaviors of Veterans with dementia: description of the tailored activity program-VA randomized trial

BACKGROUND: Behavioral symptoms accompanying dementia are associated with increased health care costs, reduced quality of life and daily functioning, heightened family caregiver burden, and nursing home placement. Standard care typically involves pharmacologic agents, but these are, at best, modestly effective, carry serious risks, including mortality, and do not address behavioral symptoms families consider most distressful and which may prompt nursing home placement. Given dementia’s devastating effects and the absence of an imminent cure, the Veterans Administration has supported the development and testing of new approaches to manage challenging behaviors at home. METHODS/DESIGN: The Tailored Activity Program – Veterans Administration is a Phase III efficacy trial designed to reduce behavioral symptoms in Veterans with dementia living with their caregivers in the community. The study uses a randomized two-group parallel design with 160 diverse Veterans and caregivers. The experimental group receives a transformative patient-centric intervention designed to reduce the burden of behavioral symptoms in Veterans with dementia. An occupational therapist conducts an assessment to identify a Veteran’s preserved capabilities, deficit areas, previous roles, habits, and interests to develop activities tailored to the Veteran. Family caregivers are then trained to incorporate activities into daily care. The attention-control group receives bi-monthly telephone contact where education on topics relevant to dementia is provided to caregivers. Key outcomes include reduced frequency and severity of behavioral symptoms using the 12-item Neuropsychiatric Inventory (primary endpoint), reduced caregiver burden, enhanced skill acquisition, efficacy using activities, and time spent providing care at 4 months; and long-term effects (8 months) on the Veteran’s quality of life and frequency and severity of behavioral symptoms, and caregiver use of activities. The programs’ impact of Veterans Administration cost is also examined. Study precision will be increased through face-to-face research team trainings with procedural manuals and review of audio-taped interviews and intervention sessions. DISCUSSION: The Tailored Activity Program – Veterans Administration is designed to improve the quality of life of Veterans with dementia and lessen the burden of care on caregivers. Activities are tailored to reflect the Veteran’s preserved capabilities and interests to enhance active engagement, while not taxing areas of cognition that are most impaired. TRIAL REGISTRATION: ClinicalTrials.gov, NCT0135756