Sound transmission testing of polymer compounds

This is the post-print version of the final paper published in Polymer Testing. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier Ltd.Acoustic properties of polymer compounds are an important consideration for many applications. Currently, there are standard test methods for the determination of these properties. There is, however, no standard for the equipment used in these tests, only a specification for the test conditions. The objective of this work was to evaluate the operation and performance of a bench top laboratory sound testing system for its potential as a simple cost effective method for the initial evaluation of materials that require specific acoustic properties. The work was limited to an investigation of the property of sound transmission loss (STL). A study of the effect of the mounting conditions for the samples on the STL was carried out. Following this, a series of polymer and polymer composite samples was tested. The results presented demonstrate the potential for the testing system as an effective standard test method for the acoustic properties of polymer composites and other materials.Technology Strategy Board, U

Bloqueio Atrioventricular Paroxístico como Causa de Síncope em Crianças sem Cardiopatia Congênita

Histórico: A síncope causada por bloqueio atrioventricular (AV) paroxístico, definido como bloqueio de segundo ou terceiro grau transitório, raramente é relatada em pacientes pediátricos sem cardiopatias congênitas. Métodos: Realizou-se uma revisao do banco de dados de arritmias da nossa instituiçao, de janeiro de 1988 a janeiro de 2007, para identificar todos os pacientes com menos de 18 anos de idade com anatomia cardíaca normal e episódios de síncope associados a bloqueio AV paroxístico. Informaçoes demográficas e clínicas foram coletadas. Resultados: Foram identificados seis pacientes, cinco do sexo feminino, com idade média de 9,3 ± 4,4 anos, que haviam sofrido episódios de síncope durante 5,6 ± 3,3 anos, em média, antes do diagnóstico (Tabela 1). Todos foram submetidos a exame físico, eletrocardiograma e ecocardiograma. Os resultados dos exames laboratoriais, inclusive para doença de Lyme, foram negativos. Nenhum deles recebia medicaçao capaz de interferir na conduçao AV nodal. Cinco dos seis episódios relatados foram atípicos para síncope vasovagal (com exceçao do paciente 6). Todos os pacientes tiveram bloqueio AV paroxístico documentado em monitor cardíaco ou gravador de Holter de 24 horas, registrado durante a síncope em pacientes internados. Houve manutençao ou aceleraçao do ritmo sinusal durante os episódios de síncope em todos os pacientes (ritmo atrial médio de 107 ± 37 bpm). Os seis pacientes receberam o implante de marcapasso transvenoso permanente, com a resoluçao dos sintomas durante um acompanhamento médio de 5,2 ± 6,3 anos. Conclusao: O bloqueio AV paroxístico é um achado raro em pacientes pediátricos, mas deve ser considerado uma etiologia possível naqueles que apresentam episódios atípicos de síncope vasovagal. A terapia utilizando marcapassos preveniu novas ocorrências em todos os seis pacientes

Bloqueio Atrioventricular Paroxístico como Causa de Síncope em Crianças sem Cardiopatia Congênita

Histórico: A síncope causada por bloqueio atrioventricular (AV) paroxístico, definido como bloqueio de segundo ou terceiro grau transitório, raramente é relatada em pacientes pediátricos sem cardiopatias congênitas. Métodos: Realizou-se uma revisao do banco de dados de arritmias da nossa instituiçao, de janeiro de 1988 a janeiro de 2007, para identificar todos os pacientes com menos de 18 anos de idade com anatomia cardíaca normal e episódios de síncope associados a bloqueio AV paroxístico. Informaçoes demográficas e clínicas foram coletadas. Resultados: Foram identificados seis pacientes, cinco do sexo feminino, com idade média de 9,3 ± 4,4 anos, que haviam sofrido episódios de síncope durante 5,6 ± 3,3 anos, em média, antes do diagnóstico (Tabela 1). Todos foram submetidos a exame físico, eletrocardiograma e ecocardiograma. Os resultados dos exames laboratoriais, inclusive para doença de Lyme, foram negativos. Nenhum deles recebia medicaçao capaz de interferir na conduçao AV nodal. Cinco dos seis episódios relatados foram atípicos para síncope vasovagal (com exceçao do paciente 6). Todos os pacientes tiveram bloqueio AV paroxístico documentado em monitor cardíaco ou gravador de Holter de 24 horas, registrado durante a síncope em pacientes internados. Houve manutençao ou aceleraçao do ritmo sinusal durante os episódios de síncope em todos os pacientes (ritmo atrial médio de 107 ± 37 bpm). Os seis pacientes receberam o implante de marcapasso transvenoso permanente, com a resoluçao dos sintomas durante um acompanhamento médio de 5,2 ± 6,3 anos. Conclusao: O bloqueio AV paroxístico é um achado raro em pacientes pediátricos, mas deve ser considerado uma etiologia possível naqueles que apresentam episódios atípicos de síncope vasovagal. A terapia utilizando marcapassos preveniu novas ocorrências em todos os seis pacientes

The Ursinus Weekly, April 27, 1972

Ursinus suffers blackout; Transformer explodes • Dr. Helen T. Garrett dies • UC students experience teaching • Dr. Robert M. Veatch to speak at Ursinus College forum • Dr. Allan Lake Rice speaks at conference • Students inducted into Omicron Delta Epsilon • Ursinus seeks $200,000 gift • Lantern elects officers for \u2772-\u2773; Spring issue expected in late May • Editorial: Stop the war • Focus: Jane Siegel • Strike • Faculty portrait: Dr. Gayle Byerly • Guest column: Dr. Allan Rice on war and peace • Letters to the editor: The need of a psychologist; Open letter to security • W.C. rains on our parade • Sing sets record • Bartholomew wins two • Ursinus starts baseball season • Travelin\u27 5\u27s history told • Modern Dance Club: fun for allhttps://digitalcommons.ursinus.edu/weekly/1123/thumbnail.jp

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

BACKGROUND: Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. METHODS: Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. RESULTS: Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. CONCLUSIONS: The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts

Clinical Remission of Sight-Threatening Non-Infectious Uveitis Is Characterized by an Upregulation of Peripheral T-Regulatory Cell Polarized Towards T-bet and TIGIT.

Background: Non-infectious uveitis can cause chronic relapsing and remitting ocular inflammation, which may require high dose systemic immunosuppression to prevent severe sight loss. It has been classically described as an autoimmune disease, mediated by pro-inflammatory Th1 and Th17 T-cell subsets. Studies suggest that natural immunosuppressive CD4+CD25+FoxP3+ T-regulatory cells (Tregs) are involved in resolution of inflammation and may be involved in the maintenance of clinical remission. Objective: To investigate whether there is a peripheral blood immunoregulatory phenotype associated with clinical remission of sight-threatening non-infectious uveitis by comparing peripheral blood levels of Treg, Th1, and Th17, and associated DNA methylation and cytokine levels in patients with active uveitic disease, control subjects and patients (with previously active disease) in clinical remission induced by immunosuppressive drugs. Methods: Isolated peripheral blood mononuclear cells (PBMC) from peripheral blood samples from prospectively recruited subjects were analyzed by flow cytometry for CD3, CD4, FoxP3, TIGIT, T-bet, and related orphan receptor γt. Epigenetic DNA methylation levels of FOXP3 Treg-specific demethylated region (TSDR), FOXP3 promoter, TBX21, RORC2, and TIGIT loci were determined in cryopreserved PBMC using a next-generation sequencing approach. Related cytokines were measured in blood sera. Functional suppressive capacity of Treg was assessed using T-cell proliferation assays. Results: Fifty patients with uveitis (intermediate, posterior, and panuveitis) and 10 control subjects were recruited. The frequency of CD4+CD25+FoxP3+ Treg, TIGIT+ Treg, and T-bet+ Treg and the ratio of Treg to Th1 were significantly higher in remission patients compared with patients with active uveitic disease; and TIGIT+ Tregs were a significant predictor of clinical remission. Treg from patients in clinical remission demonstrated a high level of in vitro suppressive function compared with Treg from control subjects and from patients with untreated active disease. PBMC from patients in clinical remission had significantly lower methylation levels at the FOXP3 TSDR, FOXP3 promoter, and TIGIT loci and higher levels at RORC loci than those with active disease. Clinical remission was also associated with significantly higher serum levels of transforming growth factor β and IL-10, which positively correlated with Treg levels, and lower serum levels of IFNγ, IL-17A, and IL-22 compared with patients with active disease. Conclusion: Clinical remission of sight-threatening non-infectious uveitis has an immunoregulatory phenotype characterized by upregulation of peripheral Treg, polarized toward T-bet and TIGIT. These findings may assist with individualized therapy of uveitis, by informing whether drug therapy has induced phenotypically stable Treg associated with long-term clinical remission

Do microplates in subduction zones leave a geological record?

Active microplate boundaries in ocean-continent subduction zones may induce deformation of the overlying plate and spatial or geochemical variations in the volcanic arc. We discuss two modern cases. The first is the South Gorda-Juan de Fuca plate boundary in the Cascadia subduction zone, where there is little or no effect on the overriding plate and the oceanic plate takes up much of the deformation. The second case is the Cocos-Rivera plate boundary in the Middle America trench, where the overlying Colima graben contains substantial deformation in a zone extending from the trench to the volcanic arc and the sub-duction-related volcanism is spatially and geochemically complex. We apply these observations to boundaries of the Arguello, Monterey, Guadalupe, and Magdalena microplates, which existed in the subduction zone west of Baja California at various times from 20 to 12.5 Ma. The past positions of these boundaries relative to Baja California are constrained by global plate reconstructions, closure of the Gulf of California, and an estimate of extension in the Mexican Basin and Range province. Existing regional mapping and our additional reconnaissance mapping show that Paleocene to Eocene fluvial and marine sedimentary rocks south of Ensenada along the western Baja California peninsula and eastward to the mid-Miocene volcanic arc are undeformed. Limited available data reveal no major spatial or geochemical variations in the mid-Miocene volcanic arc that might correlate with the past positions of the microplate boundaries. Thus these microplate boundaries had little to no effect on the overriding continental plate. The nature of Guadalupe and Magdalena interactions with North America may have been closer to the South Gorda-Juan de Fuca example, with possible internal deformation of the microplates. The Monterey and Arguello microplates may have behaved like the modern Explorer plate, with largely strike-slip motion relative to North America during their last stages of existence. Tectonic patterns similar to these examples may be expected from other plate boundaries where a plate is fragmenting as it enters a subduction zone (e.g., the Aluk plate in the trench beneath West Antarctica in early Tertiary time). Whether these microplates subsequently become attached to the overriding continental plate or to a larger oceanic plate and whether this causes deformation in the region of the former subduction zone may depend on the velocities of the nearby major plates and the relative orientations of the microplate boundaries

Lithological influences on contemporary and long-term regolith weathering at the Luquillo Critical Zone Observatory

Lithologic differences give rise to the differential weatherability of the Earth’s surface and globally variable silicate weathering fluxes, which provide an important negative feedback on climate over geologic timescales. To isolate the influence of lithology on weathering rates and mechanisms, we compare two nearby catchments in the Luquillo Critical Zone Observatory in Puerto Rico, which have similar climate history, relief and vegetation, but differ in bedrock lithology. Regolith and pore water samples with depth were collected from two ridgetops and at three sites along a slope transect in the volcaniclastic Bisley catchment and compared to existing data from the granitic Río Icacos catchment. The depth variations of solid-state and pore water chemistry and quantitative mineralogy were used to calculate mass transfer (tau) and weathering solute profiles, which in turn were used to determine weathering mechanisms and to estimate weathering rates. Regolith formed on both lithologies is highly leached of most labile elements, although Mg and K are less depleted in the granitic than in the volcaniclastic profiles, reflecting residual biotite in the granitic regolith not present in the volcaniclastics. Profiles of both lithologies that terminate at bedrock corestones are less weathered at depth, near the rock-regolith interfaces. Mg fluxes in the volcaniclastics derive primarily from dissolution of chlorite near the rock-regolith interface and from dissolution of illite and secondary phases in the upper regolith, whereas in the granitic profile, Mg and K fluxes derive from biotite dissolution. Long-term mineral dissolution rates and weathering fluxes were determined by integrating mass losses over the thickness of solid-state weathering fronts, and are therefore averages over the timescale of regolith development. Resulting long-term dissolution rates for minerals in the volcaniclastic regolith include chlorite: 8.9 × 10‾¹⁴ mol m‾² s‾¹, illite: 2.1 × 10‾¹⁴ mol m‾² s‾¹ and kaolinite: 4.0 × 10‾¹⁴ mol m‾² s‾¹. Long-term weathering fluxes are several orders of magnitude lower in the granitic regolith than in the volcaniclastic, despite higher abundances of several elements in the granitic regolith. Contemporary weathering fluxes were determined from net (rain-corrected) solute profiles and thus represent rates over the residence time of water in the regolith. Contemporary weathering fluxes within the granitic regolith are similar to the long-term fluxes. In contrast, the long-term fluxes are faster than the contemporary fluxes in the volcaniclastic regolith. Contemporary fluxes in the granitic regolith are generally also slightly faster than in the volcaniclastic. The differences in weathering fluxes over space and time between these two watersheds indicate significant lithologic control of chemical weathering mechanisms and rates