4,642 research outputs found
Lesker PVD75 E-beam Evaporator (PVD-04) Standard Operating Procedure
Standard Operating Procedure for the Lesker PVD75 E-beam Evaporator (PVD-04) located at the Quattrone Nanofabrication Facility within the Singh Center for Nanotechnology at the University of Pennsylvaniahttps://repository.upenn.edu/scn_sop/1024/thumbnail.jp
Predicting the Effects of Cerulean Warbler, Dendroica cerulea Management on Eastern Ontario Bird Species
Single-species habitat management strategies are often undertaken without explicit consideration of their effects on the larger community. Here we explore the potential effects of managing eastern Ontario deciduous forests for the Cerulean Warbler (Dendroica cerulea) by examining its potential as a biodiversity indicator species and as an umbrella species. Our results indicate that the Cerulean Warbler would not be an effective biodiversity indicator, as its distribution across the studied landscape did not coincide with areas of high avian species richness. However, the Cerulean Warbler may be effective as an umbrella species for the maintenance of populations of other canopy-nesting species that require mature deciduous forest habitats. It is hoped that the conclusions reached in Ontario, while perhaps not directly transferable to all parts of the breeding range, encourage other Cerulean Warbler researchers to ask similar questions in their study areas
Characterization of microstructural effects on small fatigue crack growth mechanisms in Ti-6242S
Design and life management of fracture critical components are made difficult by small scale deformation responses to low applied stresses in the very high cycle fatigue (VHCF) regime, where the number of cycles exceeds 107 and fatigue life is dominated by crack initiation and the growth of microstructurally small cracks. Furthermore, fatigue crack formation is extremely sensitive to microstructural features. Existing models do not fully capture small scale microstructural influences on early fatigue deformation behavior. An understanding of the interactions between the local microstructure and the plastic zone present at the crack tip of a microstructurally small fatigue crack is critical to modeling fatigue crack growth mechanisms. Plastic zone sizes at this scale are highly influenced by local microstructural characteristics such as grain boundary misorientation, phase boundaries, and the presence of precipitates. The use of multiple experimental techniques that enable study of the interactions between the crack-tip plastic zone and local microstructural features in-situ will help develop a quantitative understanding of the underlying small crack growth mechanisms. The role of microstructure on small fatigue crack growth mechanics in the near a titanium alloy Ti6242S has been investigated in the VHCF regime. An experimental methodology for in-situ ultrasonic fatigue (20 kHz) in a scanning electron microscope (SEM) has been developed to investigate mechanisms of fatigue crack formation and the growth of microstructurally small cracks in vacuum and in varying partial pressures of water vapor. In-situ observations of small crack growth behavior from focused ion beam machined micronotches located at key microstructural sites indicated a significant microstructural dependence on crack growth rates. Fatigue crack propagation behavior is also correlated with crack opening displacement and cyclic strain accumulation as measured by advanced in-situ scanning electron microscopy digital image correlation techniques. The evolution of small-scale strain fields at crack tips and in the microstructural neighborhood of the advancing crack is also examined. The specifics of the ultrasonic fatigue SEM instrumentation and the influence of microstructure on small fatigue crack propagation, crack-tip plasticity, and strain localization in the VHCF regime will be described
Qualification of low drift single-use pH sensors for use in single-use bioreactor platforms
The biopharmaceutical industry is currently limited by access to low drift, gamma stable, easy-to-integrate single-use pH sensors for application in single-use bioreactors (S.U.B.). Hamilton Company has developed the OneFerm VP 70 sensor, a unique single-use glass electrode, which provides an additional option for customers wishing to implement reliable single-use pH sensing capabilities in the S.U.B. platform. In order to demonstrate the efficacy of these devices, a series of qualification experiments were carried out using a Thermo Fisher Scientific 50L bioprocess container (BPC) custom-fitted with Hamilton OneFerm sensors. BPCs were manufactured in a cGMP facility and allowed to age for a pre-established period (either 30 or 180 days). A 14 day fed-batch cell run was executed using an in-house CHO-S cell line (mAb producing clone) and standard operating conditions. Online pH was controlled with a Hamilton EasyFerm pH sensor; reactor pH was controlled using CO2 without acid or base. Each BPC was built with 6 OneFerm sensors (containing 2 each from 3 different production lots), which were monitored using stand-alone transmitters. Offline samples were evaluated every 24 hours using an Oakton pH sensor.
The results from the initial 30 day aged BPC evaluation demonstrate functional activity of the OneFerm sensors over a 14 day fed-batch cell run using a TruBio DeltaV S.U.B. controller. Functional stability of these sensors was demonstrated by maintaining the devices in sterile culture conditions for a period of 60 days; 5 out of 6 sensors met all manufacturersâ specifications during this hold period. To determine if BPC storage time contributes to loss in sensor functionality, a 14 day fed-batch cell run was repeated using a 180 day aged BPC. All 6 OneFerm sensors met manufacturerâs specifications after the cell run with no sensor exhibiting a gross pH drift greater than 0.11 during the entire 14 day period. Additionally, all 6 sensors also met manufacturerâs specifications during the 60 day hold period with no sensor exhibiting an average gross pH drift greater than 0.15 during this extended time. Furthermore, all sensors demonstrated an average response time of less than 10 seconds following the 60 day hold period.
The results of these experiments demonstrate the effectiveness of Hamilton OneFerm sensors in the Thermo Fisher Scientific HyPerforma S.U.B. platform. Thermo Fisher Scientific has since developed a custom polycarbonate probe port adapter to robustly integrate the OneFerm sensor in a S.U.B. BPC. Future work will continue to evaluate the performance of sensors aged in BPCs for 24 to 36 months. We are excited to share this growing body of data with the bioprocess industry as probe drift, ionic strength sensitivity, and shelf life have greatly limited implementation of SU pH over the past decade. These results appear to indicate a viable technology is now available and is suitable for cGMP bio manufacturing
Effects of contaminants of emerging concern on Megaselia scalaris (Lowe, Diptera: Phoridae) and its microbial community.
Drought, rising temperatures, and expanding human populations are increasing water demands. Many countries are extending potable water supplies by irrigating crops with wastewater. Unfortunately, wastewater contains biologically active, long-lived pharmaceuticals, even after treatment. Run-off from farms and wastewater treatment plant overflows contribute high concentrations of pharmaceuticals to the environment. This study assessed the effects of common pharmaceuticals on a cosmopolitan saprophagous insect, Megaselia scalaris (Diptera: Phoridae). Larvae were reared on artificial diets spiked with contaminants of emerging concern (CECs) at environmentally relevant concentrations. Female flies showed no oviposition preference for treated or untreated diets. Larvae exposed to caffeine in diets showed increased mortality, and larvae fed antibiotics and hormones showed signs of slowed development, especially in females. The normal sex ratio observed in M. scalaris from control diets was affected by exposure to caffeine and pharmaceutical mixture treatments. There was an overall effect of treatment on the flies' microbial communities; notably, caffeine fed insects displayed higher microbial variability. Eight bacterial families accounted for approximately 95% of the total microbes in diet and insects. Our results suggest that CECs at environmentally relevant concentrations can affect the biology and microbial communities of an insect of ecological and medical importance
Spatial Scaling of Avian Population Dynamics: Population Abundance, Growth Rate, and Variability
Synchrony in population fluctuations has been identified as an important component of population dynamics. In a previous study, we determined that localâscale (\u3c15âkm) spatial synchrony of bird populations in New England was correlated with synchronous fluctuations in lepidopteran larvae abundance and with the North Atlantic Oscillation. Here we address five questions that extend the scope of our earlier study using North American Breeding Bird Survey data. First, do bird populations in eastern North America exhibit spatial synchrony in abundances at scales beyond those we have documented previously? Second, does spatial synchrony depend on what population metric is analyzed (e.g., abundance, growth rate, or variability)? Third, is there geographic concordance in where species exhibit synchrony? Fourth, for those species that exhibit significant geographic concordance, are there landscape and habitat variables that contribute to the observed patterns? Fifth, is spatial synchrony affected by a species\u27 life history traits? Significant spatial synchrony was common and its magnitude was dependent on the population metric analyzed. Twentyâfour of 29 species examined exhibited significant synchrony in population abundance: mean local autocorrelation (Ï) = 0.15; mean spatial extent (mean distance where Ï = 0) = 420.7 km. Five of the 29 species exhibited significant synchrony in annual population growth rate (mean local autocorrelation = 0.06, mean distance = 457.8 km). Ten of the 29 species exhibited significant synchrony in population abundance variability (mean local autocorrelation = 0.49, mean distance = 413.8 km). Analyses of landscape structure indicated that habitat variables were infrequent contributors to spatial synchrony. Likewise, we detected no effects of life history traits on synchrony in population abundance or growth rate. However, shortâdistance migrants exhibited more spatially extensive synchrony in population variability than either yearâround residents or longâdistance migrants. The dissimilarity of the spatial extent of synchrony across species suggests that most populations are not regulated at similar spatial scales. The spatial scale of the population synchrony patterns we describe is likely larger than the actual scale of population regulation, and in turn, the scale of population regulation is undoubtedly larger than the scale of individual ecological requirements
Lack of Equivalence in the Elemental and Stable Isotope Chemistry Within the Sagittal Otolith Pair of the Summer Flounder, Paralichthys dentatus
In fish that are not bilaterally symmetrical, the left and right sagittae are often not symmetrical, exhibiting divergent growth patterns and mass, and may have differences in chemical composition. We investigated this in the asymmetrical summer flounder Paralichthys dentatus, collected from different nursery habitats along the US east coast. Significant differences were detected in otolith mass, ÎŽ13C, ÎŽ18O, Li:Ca, Mg:Ca, and Sr:Ca, and overall chemical signatures. These results refute the hypothesis of left-right equivalence that is prevalent for bilaterally symmetrical fishes. We tested whether a specific side was better suited for classification. The best models differed between sagittae and resulted in different classification accuracies. The left otolith produced better classification accuracies. Simulated samples of randomized sets of left or right otoliths produced mean accuracies intermediate to classification and were often highly variable. We recommend that future otolith chemistry studies involving bilaterally asymmetrical species test the hypothesis of equivalence within the sagittae before randomly choosing an otolith for chemical analyses
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