Timing of mid-crustal ductile extension in the northern Snake Range metamorphic core complex, Nevada: Evidence from U/Pb zircon ages

Metamorphic core complexes within the western U.S. record a history of Cenozoic ductile and brittle extensional deformation, metamorphism, magmatism, and exhumation within the footwalls of high-angle Basin and Range normal faults. In models proposed for the formation of metamorphic core complexes there is a close temporal and spatial link between upper crustal normal faulting, lower crustal ductile extension and flow, and detachment faulting. To provide constraints on the timing of ductile extension in the northern Snake Range metamorphic core complex (Nevada) and thereby test these models, we present new 238U-206Pb dates on zircons from both deformed and undeformed rhyolite dikes intruded into this core complex. The older age bracket is from the northern dike swarm, which was emplaced in the northwestern part of the range pretectonic to syntectonic with ductile extension. The younger age bracket is from the Silver Creek dike swarm, which was emplaced in the southern part of the range after ductile extensional deformation. The 238U-206Pb zircon ages from these dikes provide tight bounds on the timing of ductile extension, between 37.806 ± 0.051 Ma and 22.49 ± 0.36 Ma. Our field observations, petrography, and 238U-206Pb zircon ages on these dikes combined with published data on the geology and kinematics of extension, moderate- and low-temperature thermochronology on lower plate rocks, and age and faulting histories of Cenozoic sedimentary basins, are interpreted as recording an episode of localized upper crustal brittle extension during the late Eocene that drove upward ductile extensional flow of hot middle crustal rocks from beneath the northern Snake Range detachment soon after, or simultaneously with, emplacement of the older dike swarm. Exhumation of the lower plate continued in a rolling hinge–isostatic rebound style; the western part of the lower plate was exhumed first and the eastern part extended ductilely either episodically or continuously until the latest Oligocene–earliest Miocene, when the post-tectonic younger dike swarm was emplaced. Major brittle slip along the eastern part of the northern Snake Range detachment and along high-angle normal faults exhumed the lower plate during middle Miocene

The recombinant expression and potential applications of bacterial organophosphate hydrolase in Zea mays L.

Organophosphate hydrolase (OPH, EC 3.1.8.1) is a bacterial enzyme with a broad spectrum of potential substrates that include organophosphorus pesticides, herbicides, and chemical warfare agents. OPH has been expressed successfully in bacterial, fungal, and insect cell culture systems; however, none of these systems produces amounts of enzyme suitable for applications outside of the research laboratory. Therefore, a transgenic Zea mays L. (maize) system was developed to express OPH as an alternate to the current OPH expression systems. The bacterial gene encoding the OPH protein was optimized for transcriptional and translational expression in maize. The optimized gene was inserted into the maize genome under the control of embryo specific, endosperm specific, and constitutive plant promoters. Select transformants were analyzed for the expression of OPH. Expression was observed in the seeds of plants transformed with each of the three constructs with the highest expression observed with the embryo specific and constitutive promoter constructs. The highest OPH expressing lines of transgenic maize had expression levels higher than those reported for the E. coli expression system. OPH was purified from transgenic maize seed and analyzed for posttranslational modification and kinetic properties. OPH was observed to undergo a glycosylation event when expressed in maize that yielded at least two forms of OPH homogolous dimer. The glycosylated form of OPH bound tightly to the Concanavalin A sepharose and remained active after months of storage at room temperature. OPH activity was checked against a number of organophosphate herbicides. Enzymatic activity was observed against the herbicide Amiprophos-methyl and kinetic properties were measured. Enzymatic activity was also tested against the organophosphate Haloxon. Transgenic maize callus, leaf, and seed tissue could be screened for the presence of the optimized opd gene by enzymatic activity. Comparison of the growth of transgenic and control callus on media containing organophosphates showed that the transgenic callus was resistant to the herbicidal effects of haloxon. Transgenic plants expressing OPH were also resistant to the herbicide bensulide when compared to control plants. This indicates that OPH can be used as a screenable marker in plant systems and may be a potential scorable marker system as well

Involvement, social class and attrition in higher education : the case of the stop out

This thesis tests the validity of three theories purporting to explain the attrition of stop outs -- why students interrupt their studies with the intent to return to school. Data were gathered at two schools, Portland State University and Reed College. Two theories, those of social class and involvement, were tested at each school as contending explanations of attrition by path analysis of parsimonious models derived by factor analysis. These theories were found to explain little of the variance of attendance pattern (less than 4.3 percent) at either school. No particular lines of causation could be demonstrated at either school. The third theory, that of career planning, asserts that students interrupt their studies to re-evaluate their course of action upon recognizing that chances of employment in their field are not good. This proposition was supported by the data at Portland State University

Automatic Boosted Flood Mapping from Satellite Data

Numerous algorithms have been proposed to map floods from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. However, most require human input to succeed, either to specify a threshold value or to manually annotate training data. We introduce a new algorithm based on Adaboost which effectively maps floods without any human input, allowing for a truly rapid and automatic response. The Adaboost algorithm combines multiple thresholds to achieve results comparable to state-of-the-art algorithms which do require human input. We evaluate Adaboost, as well as numerous previously proposed flood mapping algorithms, on multiple MODIS flood images, as well as on hundreds of non-flood MODIS lake images, demonstrating its effectiveness across a wide variety of conditions

Validation of the Lockheed Martin Morphing Concept with Wind Tunnel Testing

The Morphing Aircraft Structures (MAS) program is a Defense Advanced Research Projects Agency (DARPA) led effort to develop morphing flight vehicles capable of radical shape change in flight. Two performance parameters of interest are loiter time and dash speed as these define the persistence and responsiveness of an aircraft. The geometrical characteristics that optimize loiter time and dash speed require different geometrical planforms. Therefore, radical shape change, usually involving wing area and sweep, allows vehicle optimization across many flight regimes. The second phase of the MAS program consisted of wind tunnel tests conducted at the NASA Langley Transonic Dynamics Tunnel to demonstrate two morphing concepts and their enabling technologies with large-scale semi-span models. This paper will focus upon one of those wind tunnel tests that utilized a model developed by Lockheed Martin Aeronautics Company (LM). Wind tunnel success criteria were developed by NASA to support the DARPA program objectives. The primary focus of this paper will be the demonstration of the DARPA objectives by systematic evaluation of the wind tunnel model performance relative to the defined success criteria. This paper will also provide a description of the LM model and instrumentation, and document pertinent lessons learned. Finally, as part of the success criteria, aeroelastic characteristics of the LM derived MAS vehicle are also addressed. Evaluation of aeroelastic characteristics is the most detailed criterion investigated in this paper. While no aeroelastic instabilities were encountered as a direct result of the morphing design or components, several interesting and unexpected aeroelastic phenomenon arose during testing

High-intensity cardiac infections of Phthinomita heinigerae n. sp. (Digenea: Aporocotylidae) in the orangelined cardinalfish, Taeniamia fucata (Cantor), off Heron Island on the Great Barrier Reef.

We report a new species of aporocotylid trematode (Platyhelminthes: Digenea) from the heart of the orangelined cardinalfish, Taeniamia fucata (Cantor), from off Heron Island on the southern Great Barrier Reef. We used an integrated approach, analysing host distribution, morphology, and genetic data from the internal transcribed spacer 2 of the ribosomal DNA, to circumscribe Phthinomita heinigerae n. sp. This is the first species of Phthinomita Nolan & Cribb, 2006 reported from the Apogonidae; existing species and known 'types' are recorded from species of the Labridae, Mullidae, and Siganidae. The new species is distinguished from its 11 congeners in having a body 2977-3539 long and 16.5-22.4 times longer than wide, an anterior testis 6.2-8.2 times longer than wide and 8.3-13.0 times longer than the posterior testis, a posterior testis whose width is 35-56% of the body width, and an ovary positioned 11-13% of the body length from the posterior end, and is entirely anterior to the posterior margin of the anterior testis. In addition, 2-34 base differences (0.4-7.0% sequence divergence over 485 base positions) were detected among the ITS2 sequence representing P. heinigerae n. sp. and the 14 representing other Phthinomita species/molecular types. Prevalence and intensity of infection with P. heinigerae n. sp. was relatively high within the heart tissue of T. fucata, with 19 of 20 fish examined from off Heron Island infected (95%) with 7-25 adult worms (arithmetic mean 16.6). Infections by these parasites accounted for an occupation of 7-30% of the total estimated heart volume.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.parint.2016.05.00

Incorporating animal movement into distance sampling

R. Glennie gratefully acknowledges the Carnegie Trust for funding his work on this research project.Distance sampling is a popular statistical method to estimate the density of wild animal populations. Conventional distance sampling represents animals as fixed points in space that are detected with an unknown probability that depends on the distance between the observer and the animal. Animal movement can cause substantial bias in density estimation. Methods to correct for responsive animal movement exist, but none account for nonresponsive movement independent of the observer. Here, an explicit animal movement model is incorporated into distance sampling, combining distance sampling survey data with animal telemetry data. Detection probability depends on the entire unobserved path the animal travels. The intractable integration over all possible animal paths is approximated by a hidden Markov model. A simulation study shows the method to be negligibly biased (<5%) in scenarios where conventional distance sampling overestimates abundance by up to 100%. The method is applied to line transect surveys (1999–2006) of spotted dolphins (Stenella attenuata) in the eastern tropical Pacific where abundance is shown to be positively biased by 21% on average, which can have substantial impact on the population dynamics estimated from these abundance estimates and on the choice of statistical methodology applied to future surveysPreprintPostprintPeer reviewe

Immunohistochemical localization patterns for vimentin and other intermediate filaments in calcified ovarian fibrothecoma

PROBLEM: To describe immunohistochemical features encountered in ovarian fibrothecoma with correlation to clinical presentation and surgical management. METHOD OF STUDY: A female age 75 presented for evaluation of melena. The patient reported total abdominal hysterectomy and removal of both ovaries 40 years earlier. RESULTS: CA-125 was normal and there was no evidence of hyperestrogen effect. Pelvic CT revealed a partially calcified 7 cm pelvic mass without adenopathy or ascites; ultrasound was confirmatory. Endoscopy identified three benign intestinal tubular adenomas. Following laparoscopic excision of the pelvic tumor immunohistochemichal analysis of the mass showed negative staining for keratin, S100 protein, inhibin, calretinin, melan A, smooth muscle actin, CD34, CD117, and desmin. The tissue was positive for vimentin, however. CONCLUSION: Ovarian fibrothecomas represent an ovarian stromal neoplasm developing in a wide spectrum of clinical settings. Particularly if oophorectomy is stated to have been performed remote from the time of index presentation, the status of the ovaries must be considered whenever pelvic pathology is encountered. We describe a calcified ovarian fibrothecoma identified during gastroenterology investigation and confirmed immunohistochemically via high amplitude vimentin signal

Complex Independent Component Analysis of Frequency-Domain Electroencephalographic Data

Independent component analysis (ICA) has proven useful for modeling brain and electroencephalographic (EEG) data. Here, we present a new, generalized method to better capture the dynamics of brain signals than previous ICA algorithms. We regard EEG sources as eliciting spatio-temporal activity patterns, corresponding to, e.g., trajectories of activation propagating across cortex. This leads to a model of convolutive signal superposition, in contrast with the commonly used instantaneous mixing model. In the frequency-domain, convolutive mixing is equivalent to multiplicative mixing of complex signal sources within distinct spectral bands. We decompose the recorded spectral-domain signals into independent components by a complex infomax ICA algorithm. First results from a visual attention EEG experiment exhibit (1) sources of spatio-temporal dynamics in the data, (2) links to subject behavior, (3) sources with a limited spectral extent, and (4) a higher degree of independence compared to sources derived by standard ICA.Comment: 21 pages, 11 figures. Added final journal reference, fixed minor typo