The bioaccumulation of persistent contaminants by zebra mussels and their effects on state-endangered common terns

Common terns currently are listed as endangered or threatened in many states, including Illinois, Vermont, Pennsylvania, Ohio, Wisconsin, Michigan, and New York, and a species of special concern by the U.S. Fish and Wildlife Service (USFWS, 2002). The sole remaining nesting colony in Illinois is located at the Naval Station Great Lakes (NSGL) in Lake County where intensive management by the Illinois Department of Natural Resources has reduced nest predation and increased the number of eggs that hatch. However, the overall reproductive success (the number of young successfully reaching independence) has not improved. Observations of gross deformities in hatchlings (i.e. compromised feather development and cross-bill), lethargic behavior of young birds, and lesions, suggested the influence of environmental contaminants (Jablonski et al., 2005). I investigated if there were significant levels of environmental contaminants in eggs and nestlings of common terns. While there were minimal concentration of selenium, mercury, lead, and cadmium, there were large concentration of polychlorinated biphenyls (PCBs) in both the eggs and nestlings. The greater amounts of PCBs in older chicks than younger chicks suggest local contamination. In order to potentially manage the factors responsible for exposing the terns to PCBs I investigated the pathway by which PCBs were exposed to terns. The two most likely biological pathways as determined by research on Great Lake fishes were investigated. The first pathway is through atmospheric deposition of PCBs and resuspension of PCB-ladel sediment which are subsequently acquired by filter-feeding fish (e.g. alewives, Alosa pseudoharengus) and then pelagic fish (e.g. lake trout, Salvelinus namaychus) or in this case terns. The second pathway explored was via the biodeposits of zebra mussels which are consumed by round gobies (Neogobius melanostromus) and ultimately littoral fish (e.g. small-mouthed bass, Micropterus dolomieui) or terns. Because common terns breed in near-shore sites where concentrations of zebra mussels are found, as well as forage in more pelagic environments it is possible that either or both pathways may be contributing to their PCB exposure. Field experiments and stable isotope analyses demonstrated that the most likely pathway by which terns are exposed to PCBs is via alewives, similar to how apex predators such as lake trout acquire PCBs. Biodeposits from zebra mussels do not appear to be a significant factor in PCB accumulation in terns. The impact of PCB exposure on birds can vary widely, however in this situation we choise to investigate one specific behavior often affected by PCB exposure, parental attentiveness. PCBs are known to cause endocrine disruption which ultimately results in reduced brooding of young and incubation of eggs. I used temperature sensors to quantify nest temperatures and parental attentiveness during incubation. High concentrations of PCBs in our study population appear to be leading to poor parental attentiveness, and extended periods of absence during incubation and brooding, ultimately leading to poor reproductive success. Common terns are perilously close to being extirpated in Illinois and management of PCB exposure will be difficult. I propose that additional testing should be conducted to locate a site with less PCB contamination and then to move the tern colony to this location, possibly using social cues as has been done with other tern species in Illinois. PCBs are having a profound impact on common tern populations in Illinois and without moving the colony it is likely that the population will continue to decline.

Transactions and schema evolution in a persistent object-oriented programming system

Applications are subject of a continuous evolution process with a profound impact on their underlining data model, hence requiring frequent updates in the applications' class structure and database structure as well. This twofold problem, schema evolution and instance adaptation, usually known as database evolution, is addressed in this thesis. Additionally, we address concurrency and error recovery problems with a novel meta-model and its aspect-oriented implementation. Modern object-oriented databases provide features that help programmers deal with object persistence, as well as all related problems such as database evolution, concurrency and error handling. In most systems there are transparent mechanisms to address these problems, nonetheless the database evolution problem still requires some human intervention, which consumes much of programmers' and database administrators' work effort. Earlier research works have demonstrated that aspect-oriented programming (AOP) techniques enable the development of flexible and pluggable systems. In these earlier works, the schema evolution and the instance adaptation problems were addressed as database management concerns. However, none of this research was focused on orthogonal persistent systems. We argue that AOP techniques are well suited to address these problems in orthogonal persistent systems. Regarding the concurrency and error recovery, earlier research showed that only syntactic obliviousness between the base program and aspects is possible. Our meta-model and framework follow an aspect-oriented approach focused on the object-oriented orthogonal persistent context. The proposed meta-model is characterized by its simplicity in order to achieve efficient and transparent database evolution mechanisms. Our meta-model supports multiple versions of a class structure by applying a class versioning strategy. Thus, enabling bidirectional application compatibility among versions of each class structure. That is to say, the database structure can be updated because earlier applications continue to work, as well as later applications that have only known the updated class structure. The specific characteristics of orthogonal persistent systems, as well as a metadata enrichment strategy within the application's source code, complete the inception of the meta-model and have motivated our research work. To test the feasibility of the approach, a prototype was developed. Our prototype is a framework that mediates the interaction between applications and the database, providing them with orthogonal persistence mechanisms. These mechanisms are introduced into applications as an {\it aspect} in the aspect-oriented sense. Objects do not require the extension of any super class, the implementation of an interface nor contain a particular annotation. Parametric type classes are also correctly handled by our framework. However, classes that belong to the programming environment must not be handled as versionable due to restrictions imposed by the Java Virtual Machine. Regarding concurrency support, the framework provides the applications with a multithreaded environment which supports database transactions and error recovery. The framework keeps applications oblivious to the database evolution problem, as well as persistence. Programmers can update the applications' class structure because the framework will produce a new version for it at the database metadata layer. Using our XML based pointcut/advice constructs, the framework's instance adaptation mechanism is extended, hence keeping the framework also oblivious to this problem. The potential developing gains provided by the prototype were benchmarked. In our case study, the results confirm that mechanisms' transparency has positive repercussions on the programmer's productivity, simplifying the entire evolution process at application and database levels. The meta-model itself also was benchmarked in terms of complexity and agility. Compared with other meta-models, it requires less meta-object modifications in each schema evolution step. Other types of tests were carried out in order to validate prototype and meta-model robustness. In order to perform these tests, we used an OO7 small size database due to its data model complexity. Since the developed prototype offers some features that were not observed in other known systems, performance benchmarks were not possible. However, the developed benchmark is now available to perform future performance comparisons with equivalent systems. In order to test our approach in a real world scenario, we developed a proof-of-concept application. This application was developed without any persistence mechanisms. Using our framework and minor changes applied to the application's source code, we added these mechanisms. Furthermore, we tested the application in a schema evolution scenario. This real world experience using our framework showed that applications remains oblivious to persistence and database evolution. In this case study, our framework proved to be a useful tool for programmers and database administrators. Performance issues and the single Java Virtual Machine concurrent model are the major limitations found in the framework.

2-categories and cyclic homology

The topic of this thesis is the application of distributive laws between comonads to the theory of cyclic homology. The work herein is based on the three papers 'Cyclic homology arising from adjunctions', 'Factorisations of distributive laws', and 'Hochschild homology, lax codescent,and duplicial structure', to which the current author has contributed. Explicitly, our main aims are: 1) To study how the cyclic homology of associative algebras and of Hopf algebras in the original sense of Connes and Moscovici arises from a distributive law, and to clarify the role of different notions of bimonad in this generalisation. 2) To extend the procedure of twisting the cyclic homology of a unital associative algebra to any duplicial object defined by a distributive law. 3) To study the universality of Bohm and Stefan’s approach to constructing duplicial objects, which we do in terms of a 2-categorical generalisation of Hochschild (co)homology. 4) To characterise those categories whose nerve admits a duplicial structure.

Persistent localized states for a chaotically mixed bistable reaction

We describe the evolution of a bistable chemical reaction in a closed two-dimensional chaotic laminar flow, from a localized initial disturbance. When the fluid mixing is sufficiently slow, the disturbance may spread and eventually occupy the entire fluid domain. By contrast, rapid mixing tends to dilute the initial state and so extinguish the disturbance. Such a dichotomy is well known. However, we report here a hitherto apparently unremarked intermediate case, a persistent highly localized disturbance. Such a localized state arises when the Damkoehler number is great enough to sustain a "hot spot," but not so great as to lead to global spread. We show that such a disturbance is located in the neighborhood of an unstable periodic orbit of the flow, and we describe some limited aspects of its behavior using a reduced, lamellar model. Copyright American Physical Society (APS) 2006.

Carbon-carbon bond formation methods for the preparation of shape-persistent architectures

Carbon-rich, conjugated organic scaffolding is a popular basis for functional materials, especially for electronic and photonic applications. However, synthetic methods for generating these types of materials lack diversity and, in many cases, efficiency; the insistence of investigators focusing on the properties of the end product, rather than the process in which it was created, has led to the current state of the relatively homogeneous synthetic chemistry of functional organic materials. Because of this, there is plenty of room for improvement at the most basic level. Problems endemic to the preparation of carbon-rich scaffolding can, in many cases, be solved with modern advances in synthetic methodology. We seek to apply this synthesis-focused paradigm to solve problems in the preparation of carbon-rich scaffolds. Herein, the development and utilization of three methodologies: iridium-catalyzed arene C-H borylation; zinc- mediated alkynylations; and Lewis acid promoted Mo nitride-alkyne metathesis, are presented as improvements for the preparation of carbon-rich architectures. In addition, X-ray crystallographic analysis of two classes of compounds are presented. First, an analysis of carbazole-containing arylene ethynylene macrocycles showcases the significance of alkyl chain identity on solid-state morphology. Second, a class of rigid zwitterionic metal-organic compounds display an unusual propensity to crystallize in the absence of inversion symmetry. Hirshfeld surface analysis of these crystalline materials demonstrates that subtle intermolecular interactions are responsible for the overall packing motifs in this class of compounds.

Isolated Aortitis Presenting with an Annoying Persistent Cough: A Case Report

Objectives: To report a case of idiopathic aortitis presenting with chronic cough. Materials and Methods: the Authors describe the case of a 72-year-old man with dry cough, worsening fatigue, weight loss and elevated systemic inflammatory markers. Results: A PET-CT scan showed diffuse thickening of the thoracic aorta and confirmed the diagnosis of aortitis. Systemic corticosteroid therapy was initiated and complete remission was achieved in six months. Conclusion: Persistent dry cough of unknown origin, especially when associated with systemic inflammation, demands a thorough differential diagnosis and should not be underrated.

Persistent infectious and tropical diseases in immigrant correctional populations

A number of infectious diseases amongst travelers and the immigrant populations are a major public health concern. Some have a long incubation period or remain asymptomatic or paucisymptomatic for many years before leading to significant clinical manifestations and/or complications. HIV, hepatitis B and C, tuberculosis or latent syphilis are among the most significant persistent diseases in migrants. Schistosomiasis and strongyloidiasis, for instance, are persistent helminthic infections that may cause significant morbidity, particularly in patients co-infected with HIV, hepatitis B and C. Chagas disease, which was initially confined to Latin America, must also now be considered in immigrants from endemic countries. Visceral leishmaniasis and malaria are other examples of parasitic diseases that must be taken into account by physicians treating incarcerated migrants. The focus of this review article is on the risk of neglected tropical diseases in particularly vulnerable correctional populations and on the risk of infectious diseases that commonly affect migrants but which are often underestimated.

Persistent Truncus Arteriosus With Intact Ventricular Septum: Clinical, Hemodynamic and Short-term Surgical Outcome

Introduction: Truncus arteriosus with intact ventricular septum is a rare and unique variant of persistent truncus arteriosus (PTA) which usually presents with central cyanosis and congestive heart failure in neonate and early infancy. Associated cardiac and non-cardiac anomalies may affect morbidity and mortality of these patients. Case Presentation: We describe clinical presentation, echocardiography and angiographic features of a 7-month old boy with PTA and intact ventricular septum who underwent surgical repair of the anomaly at our institution. Operative findings, surgical procedure and short-term outcome are reported. Conclusions: While our patient had systemic pulmonary arterial pressure at the time of complete surgical repair, it was improved after surgery.

Development of measurement and modeling techniques to quantify atmospheric deposition of persistent, bioaccumulative and toxic chemicals in the Great Lakes

Measurement and modeling techniques were developed to improve over-water gaseous air-water exchange measurements for persistent bioaccumulative and toxic chemicals (PBTs). Analytical methods were applied to atmospheric measurements of hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Additionally, the sampling and analytical methods are well suited to study semivolatile organic compounds (SOCs) in air with applications related to secondary organic aerosol formation, urban, and indoor air quality. A novel gas-phase cleanup method is described for use with thermal desorption methods for analysis of atmospheric SOCs using multicapillary denuders. The cleanup selectively removed hydrogen-bonding chemicals from samples, including much of the background matrix of oxidized organic compounds in ambient air, and thereby improved precision and method detection limits for nonpolar analytes. A model is presented that predicts gas collection efficiency and particle collection artifact for SOCs in multicapillary denuders using polydimethylsiloxane (PDMS) sorbent. An approach is presented to estimate the equilibrium PDMS-gas partition coefficient (Kpdms) from an Abraham solvation parameter model for any SOC. A high flow rate (300 L min-1) multicapillary denuder was designed for measurement of trace atmospheric SOCs. Overall method precision and detection limits were determined using field duplicates and compared to the conventional high-volume sampler method. The high-flow denuder is an alternative to high-volume or passive samplers when separation of gas and particle-associated SOCs upstream of a filter and short sample collection time are advantageous. A Lagrangian internal boundary layer transport exchange (IBLTE) Model is described. The model predicts the near-surface variation in several quantities with fetch in coastal, offshore flow: 1) modification in potential temperature and gas mixing ratio, 2) surface fluxes of sensible heat, water vapor, and trace gases using the NOAA COARE Bulk Algorithm and Gas Transfer Model, 3) vertical gradients in potential temperature and mixing ratio. The model was applied to interpret micrometeorological measurements of air-water exchange flux of HCB and several PCB congeners in Lake Superior. The IBLTE Model can be applied to any scalar, including water vapor, carbon dioxide, dimethyl sulfide, and other scalar quantities of interest with respect to hydrology, climate, and ecosystem science.

Versioning Concept Schemes for Persistent Retrieval

Things change. Words change, meaning changes and use changes both words and meaning. In information access systems this means concept schemes such as thesauri or clas- sification schemes change. They always have. Concept schemes that have survived have evolved over time, moving from one version, often called an edition, to the next. If we want to manage how words and meanings - and as a conse- quence use - change in an effective manner, and if we want to be able to search across versions of concept schemes, we have to track these changes. This paper explores how we might expand SKOS, a World Wide Web Consortium (W3C) draft recommendation in order to do that kind of tracking.The Simple Knowledge Organization System (SKOS) Core Guide is sponsored by the Semantic Web Best Practices and Deployment Working Group. The second draft, edited by Alistair Miles and Dan Brickley, was issued in November 2005. SKOS is a “model for expressing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, folksonomies, other types of controlled vocabulary and also concept schemes embedded in glossaries and terminologies” in RDF. How SKOS handles version in concept schemes is an open issue. The current draft guide suggests using OWL and DCTERMS as mechanisms for concept scheme revision.As it stands an editor of a concept scheme can make notes or declare in OWL that more than one version exists. This paper adds to the SKOS Core by introducing a tracking sys- tem for changes in concept schemes. We call this tracking system vocabulary ontogeny. Ontogeny is a biological term for the development of an organism during its lifetime. Here we use the ontogeny metaphor to describe how vocabularies change over their lifetime. Our purpose here is to create a conceptual mechanism that will track these changes and in so doing enhance information retrieval and prevent document loss through versioning, thereby enabling persistent retrieval.

Hepatic Involvement In Paediatric Patients With Paracoccidioidomycosis: A Histological Study.

Paracoccidioidomycosis is a systemic mycosis that is endemic to certain countries in Latin America. This study aimed to describe the histological features of liver involvement in patients with paracoccidioidomycosis aged <16 years of age who were treated between 1980 and 2010, with a diagnosis that was confirmed by detection of the fungus by pathological examination. Liver tissue was obtained from one necropsy and 12 biopsies. Throughout 2007, biopsies were taken from patients with persistent jaundice or portal hypertension, after which biopsies became indicated due to elevated aminotransferase and low albumin levels. Using haematoxylin and eosin (H&E), Masson's trichrome and immunohistochemical (CK7 and CK19) staining, we noted degenerative alterations in bile duct cells and inflammatory injury to the bile ducts in 10 biopsies. Using immunohistochemistry for CK7 and CK19, we observed ductal proliferation in all 12 samples. Bile duct injuries by inflammatory cells might explain the predominant increase in canalicular enzymes; immunohistochemistry is more sensitive in demonstrating ductular reactions and might show changes that are not apparent on H&E staining.

Long-term Postoperative Atrophy Of Contralateral Hippocampus And Cognitive Function In Unilateral Refractory Mtle With Unilateral Hippocampal Sclerosis.

This study aimed to evaluate long-term atrophy in contralateral hippocampal volume after surgery for unilateral MTLE, as well as the cognitive outcome for patients submitted to either selective transsylvian amygdalohippocampectomy (SelAH) or anterior temporal lobe resection (ATL). We performed a longitudinal study of 47 patients with MRI signs of unilateral hippocampal sclerosis (23 patients with right-sided hippocampal sclerosis) who underwent surgical treatment for MTLE. They underwent preoperative/postoperative high-resolution MRI as well as neuropsychological assessment for memory and estimated IQ. To investigate possible changes in the contralateral hippocampus of patients, we included 28 controls who underwent two MRIs at long-term intervals. The volumetry using preoperative MRI showed significant hippocampal atrophy ipsilateral to the side of surgery when compared with controls (p<0.0001) but no differences in contralateral hippocampal volumes. The mean postoperative follow-up was 8.7 years (± 2.5 SD; median=8.0). Our patients were classified as Engel I (80%), Engel II (18.2%), and Engel III (1.8%). We observed a small but significant reduction in the contralateral hippocampus of patients but no volume changes in controls. Most of the patients presented small declines in both estimated IQ and memory, which were more pronounced in patients with left TLE and in those with persistent seizures. Different surgical approaches did not impose differences in seizure control or in cognitive outcome. We observed small declines in cognitive scores with most of these patients, which were worse in patients with left-sided resection and in those who continued to suffer from postoperative seizures. We also demonstrated that manual volumetry can reveal a reduction in volume in the contralateral hippocampus, although this change was mild and could not be detected by visual analysis. These new findings suggest that dynamic processes continue to act after the removal of the hippocampus, and further studies with larger groups may help in understanding the underlying mechanisms.

The Consequences Of Refractory Epilepsy And Its Treatment.

Seizures in some 30% to 40% of patients with epilepsy fail to respond to antiepileptic drugs or other treatments. While much has been made of the risks of new drug therapies, not enough attention has been given to the risks of uncontrolled and progressive epilepsy. This critical review summarizes known risks associated with refractory epilepsy, provides practical clinical recommendations, and indicates areas for future research. Eight international epilepsy experts from Europe, the United States, and South America met on May 4, 2013, to present, review, and discuss relevant concepts, data, and literature on the consequences of refractory epilepsy. While patients with refractory epilepsy represent the minority of the population with epilepsy, they require the overwhelming majority of time, effort, and focus from treating physicians. They also represent the greatest economic and psychosocial burdens. Diagnostic procedures and medical/surgical treatments are not without risks. Overlooked, however, is that these risks are usually smaller than the risks of long-term, uncontrolled seizures. Refractory epilepsy may be progressive, carrying risks of structural damage to the brain and nervous system, comorbidities (osteoporosis, fractures), and increased mortality (from suicide, accidents, sudden unexpected death in epilepsy, pneumonia, vascular disease), as well as psychological (depression, anxiety), educational, social (stigma, driving), and vocational consequences. Adding to this burden is neuropsychiatric impairment caused by underlying epileptogenic processes (essential comorbidities), which appears to be independent of the effects of ongoing seizures themselves. Tolerating persistent seizures or chronic medicinal adverse effects has risks and consequences that often outweigh risks of seemingly more aggressive treatments. Future research should focus not only on controlling seizures but also on preventing these consequences.

Respiratory Viruses Are Continuously Detected In Children With Chronic Tonsillitis Throughout The Year.

To evaluate the oscillations on the viral detection in adenotonsillar tissues from patients with chronic adenotonsillar diseases as an indicia of the presence of persistent viral infections or acute subclinical infections. Cross-sectional prospective study. Tertiary hospital. The fluctuations of respiratory virus detection were compared to the major climatic variables during a two-year period using adenoids and palatine tonsils from 172 children with adenotonsillar hypertrophy and clinical evidence of obstructive sleep apnoea syndrome or recurrent adenotonsillitis, without symptoms of acute respiratory infection (ARI), by TaqMan real-time PCR. The rate of detection of at least one respiratory virus in adenotonsillar tissue was 87%. The most frequently detected viruses were human adenovirus in 52.8%, human enterovirus in 47.2%, human rhinovirus in 33.8%, human bocavirus in 31.1%, human metapneumovirus in 18.3% and human respiratory syncytial virus in 17.2%. Although increased detection of human enterovirus occurred in summer/autumn months, and there were summer nadirs of human respiratory syncytial virus in both years of the study, there was no obvious viral seasonality in contrast to reports with ARI patients in many regions of the world. Respiratory viruses are continuously highly detected during whole year, and without any clinical symptomatology, indicating that viral genome of some virus can persist in lymphoepithelial tissues of the upper respiratory tract.