cssi/SciSciGPT-SciSciNet huggingface dataset:
Direct observation of intermediates in the SufS cysteine desulfurase reaction reveals functional roles of conserved active-site residues.

Iron-sulfur (Fe-S) clusters are necessary for the proper functioning of numerous metalloproteins. Fe-S cluster (Isc) and sulfur utilization factor (Suf) pathways are the key biosynthetic routes responsible for generating these Fe-S cluster prosthetic groups in Escherichia coli. Although Isc dominates under normal conditions, Suf takes over during periods of iron depletion and oxidative stress. Sulfur acquisition via these systems relies on the ability to remove sulfur from free cysteine using a cysteine desulfurase mechanism. In the Suf pathway, the dimeric SufS protein uses the cofactor pyridoxal 5′-phosphate (PLP) to abstract sulfur from free cysteine, resulting in the production of alanine and persulfide. Despite much progress, the stepwise mechanism by which this PLP-dependent enzyme operates remains unclear. Here, using rapid-mixing kinetics in conjunction with X-ray crystallography, we analyzed the pre-steady-state kinetics of this process while assigning early intermediates of the mechanism. We employed H123A and C364A SufS variants to trap Cys-aldimine and Cys-ketimine intermediates of the cysteine desulfurase reaction, enabling direct observations of these intermediates and associated conformational changes of the SufS active site. Of note, we propose that Cys-364 is essential for positioning the Cys-aldimine for Cα deprotonation, His-123 acts to protonate the Ala-enamine intermediate, and Arg-56 facilitates catalysis by hydrogen bonding with the sulfhydryl of Cys-aldimine. Our results, along with previous SufS structural findings, suggest a detailed model of the SufS-catalyzed reaction from Cys binding to C–S bond cleavage and indicate that Arg-56, His-123, and Cys-364 are critical SufS residues in this C–S bond cleavage pathway.
Recursive Markov Systems with Small Noise

In Chap. 3 we presented several examples of representations and how they could be used for large deviation analysis.
A Seismic Damage Model for Masonry Structures

Masonry structures are common in seismic areas despite their generally poor performance in past earthquakes. Loss of lives and severe damage to masonry structures during earthquakes, such as the 1976 Tangshan earthquake, underscores the need for a method to assess the potential damage to masonry structures subjected to seismic ground motions. Even though limiting the damage and preventing collapse are implicit in many building codes, the lack of a quantitative measure of damage has prevented the explicit consideration of damage during design. A damage model is developed, expressed in terms of a damage index that is a function of the maximum deformation and hysteretic energy.
Participatory asymmetry: Theorizing media objects and media flows in a framework of participatory production

Social media develops a common asymmetry: few contribute much, the majority little. By “participatory asymmetry” we understand this long tail of participatory production as an interactive dynamic among two types of social media users, regular and sporadic, that shapes the curation of social media spaces. Examining online discussions surrounding massive, open, online courses (MOOCs), we observe interactive differences between regular and sporadic users that shape patterns of social media curation across the networked discussion forums of a major, online newspaper. Whereas regular users reply directly to other users to durably articulate discussions as “media objects;” sporadic users post one-to-many messages which aggregate in platform-reconfigurable cascades of social media or “media flows.” By mapping the relationship between regular and sporadic participation, one-to-one and one-to-many interaction, and the curation of social media spaces in patterns of media objects and flows, we propose a four-part typology of participatory asymmetry: broadcast, feedback, moderated, and dialogic.
Safe and Sound: Artificial Intelligence in Hazardous Applications. John Fox and Subrata Das. Menlo Park, CA: AAAI Press/MIT Press, 2000, 325 pp., $40.00. ISBN 0-262-06211-9.

This curiously titled book tries to address several important topics in the application of artificial intelligence methods to medical decision making. It succeeds only where it presents a knowledge representation model and derived system that are highly technical, clearly the area of expertise of the authors. The volume contains three sections. The first, “Cognitive Science to Cognitive Engineering”, begins with a general review of computer applications in medicine, mentions classic work in passing, and illustrates the role of uncertainty in medical decision making. This section ends with …
Genetic characterization and long-term management of severely affected siblings with intellectual developmental disorder with cardiac arrhythmia syndrome.

Abstract We report two brothers with severe global cognitive and motor delay, cortical visual impairment and sick sinus syndrome who were born to consanguineous parents. Standard genetic evaluations did not reveal the cause of their mental retardation. As expected, chromosomal microarray (CMA) revealed extensive regions of homozygosity. Exome sequencing revealed that both affected boys were homozygous for a nonsense mutation in the G-protein β5 (GNB5) gene (NM_016194.3:c.1032C > G; Tyr344Ter), and that the parents were carriers of this mutation. No other DNA variants that were explanatory for the sick sinus or the developmental delay/intellectual disability were identified, and no other clinical parameters are likely to have contributed to this unusual combination of phenotypes. The neurologic features of our patients are more severe than those of most of the other patients previously reported with GNB5 variants, probably because of the homozygous, complete loss-of-function (nonsense/stop-gain) nature of their variant, and their clinical course has been monitored for longer duration.
Extrinsic size dependent plastic deformability of ZnS micropillars

Abstract ZnS has been widely used as an infrared optical material due to its superb optical properties, but its mechanical properties are less well understood. In this study, we investigated the size-dependent mechanical behavior of vacuum hot-pressed ZnS micropillars with a diameter of 3, 1.5, and 0.5 μ m by in-situ microcompression tests in a scanning electron microscope. A clear size effect was observed. The 3 μ m micropillars showed the highest variability of stress-strain behavior. Whereas the 0.5 μ m pillars exhibited higher flow stress and improved strain-hardening capability to a compressive strain of ~10%. Post-mortem microscopy analyses coupled with ASTAR crystal orientation mapping suggest that plastic deformation is accommodated by stress-induced wurtzite-to-sphalerite phase transformation and the formation of abundant stacking faults and deformation twins. Meanwhile, the substantial strain hardening derives from preexisting stacking faults, twin boundaries, and grain boundaries that hinder the propagation of partial dislocations. This study provides a fresh perspective on the design of ceramic materials with high strength and plastic flow ability.
Method for measurement of TRISO kernel and layer volumes by X-ray computed tomography

Abstract Layer dimensions are key parameters for as-fabricated tristructural-isotropic (TRISO) particle fuel as well as for post-irradiation examination of particle performance. Layer thicknesses are typically measured by optical microscopy of the particle cross section near mid-plane, while layer volumes are estimated with serial sectioning and microscopy. This method for measuring layer volumes is limited due to the resolution limit imposed by slice thickness and the effect of the polishing process on delicate irradiated particle microstructures. Image processing software has been developed to segregate the three-dimensional (3D) TRISO particle images provided by x-ray computed tomography (XCT) into high-resolution volumetric data for the kernel, all particle layers, and any internal voids introduced during irradiation. These data can be used to analyze key in-reactor behaviors of TRISO particles such as kernel swelling or buffer shrinkage, which are important inputs for fuel performance modeling.
Neoseiulus californicus (McGregor) and Neoseiulus fallacis (Garman): larval responsesto prey and humidity, nymphal feeding drive and nymphal predation on phytoseiid eggs

Are Neoseiulus californicus (McGregor) and Neoseiulus fallacis (Garman) both specialized predators of spider mites? As part of a series of studies made to answer this question, responses by larvae were assessed in treatments either with or without prey (Tetranychus urticae Koch) and with either moderate or high relative humidities (a factor that may distinguish between these two morphologically similar species). Neoseiulus fallacis larvae had more feeding, ambulatory activity and jerking (intra– or interspecific communication) in all treatments than N. californicus. The percent egg hatch was less and development took longer for N. fallacis larvae than for N. californicus larvae without prey at moderate humidity levels. The nymphs of both mites showed similar drives to feed 1–2>h after being held 12–48 h without food and then given eggs of T. urticae. Neoseiulus californicus nymphs fed more on the eggs of either phytoseiid and thereafter became adults than did N. fallacis nymphs. These data indicate that N. californicus may be a less specialized predator of spider mites than is N. fallacis.
360 virtual reality pediatric mass casualty incident: A cross sectional observational study of triage and out-of-hospital intervention accuracy at a national conference.

Objective With adolescent mass casualty incidents (MCI) on the rise, out-of-hospital readiness is critical to optimize disaster response. We sought to test the feasibility and acceptability of a 360 Virtual Reality (360 VR) platform for disaster event decisionmaking. Methods This was a cross-sectional observational assessment of a subject's ability to triage and perform out-of-hospital interventions using a 360 VR MCI module. A convenience sample of attendees was recruited over 1.5 days from the American College of Emergency Physicians (ACEP) national conference in San Diego, CA. Results Two hundred and seven (207) subjects were enrolled. Ninety-six (46%) subjects identified as attendings, 66 (32%) as residents, 13 (6%) as medical students, 4 (2%) as emergency medical technicians and 28 (14%) as other. When comparing mean scores between groups, physicians who were 40 years old (8.7 vs 6.5, P < 0.001). Residents achieved higher scores than attendings (8.6 vs 7.5, P = 0.005). Based on a 5-point Likert scale, participants felt the 360 VR experience was engaging (median = 5) and enjoyable (median = 5). Most felt that 360 VR was more immersive than mannequin-based simulation training (median = 5). Conclusion We conclude that 360 VR is a feasible platform for assessing triage and intervention decisionmaking for adolescent MCIs. It is well received by subjects and may have a role as a training and education tool for disaster readiness. In this era of distanced learning, 360 VR is an attractive option for future immersive educational experiences.
Increasing Social Interactions of Preschool Children With Autism Through Cooperative Outdoor Play

Unstructured activity periods are central components of early childhood education programs. Deficits in social communication and social interaction presented by children with autism spectrum disord...
Ferroakustische Resonanz

Es wird eine quantenmechanische Theorie der ferroakustischen Resonanz gegeben. Die Wechselwirkung zwischen Spinwellen und Phononen wird formuliert und die neuen Eigenzustande, die magnetoelastischen Wellen, diskutiert. Die Phanomene der anomalen Dispersion, wie Dampfung und Rotation des Schallwellenpolarisationsvektors, werden berechnet. Die Beziehung zur klassischen Beschreibung wird dargelegt.
Virtual Encounters with Cultural Difference: Ethically Representing the Cultural “Other” in VR Journalism

This chapter addresses the journalists who use virtual reality (VR) to cover international events, making observations on the best practices for doing this type of digital news reporting. The chapter specifically focuses on two properties of VR journalism: (1) the medium’s simulation of presence at the scene and (2) the medium’s simulation of the audience’s cross-cultural encounters with “other” people. Drawing upon the critical frameworks found in postcolonial studies, this chapter will argue that there is a need for digital journalists to cultivate more critical self-reflexivity, if they hope to use VR in a way that does not flatten or sensationalize cultural difference.
The Zienkiewicz/Zhu Error Estimation Procedure

Purpose of Lesson To introduce smoothing approaches for estimating errors in individual finite elements and to demonstrate the use of error estimators to improve finite element models.
An Introduction to Orbital-Free Density Functional Theory

Given a quantum mechanical system of N electrons and an external potential (which typically consists of the potential due to a collection of nuclei), the traditional approach to determining its ground-state energy involves the optimization of the corresponding wavefunction, a function of 3N dimensions, without considering spin variables. As the number of particles increases, the computation quickly becomes prohibitively expensive. Nevertheless, electrons are indistinguishable so one could intuitively expect that the electron density — N times the probability of finding any electron in a given region of space — might be enough to obtain all properties of interest about the system. Using the electron density as the sole variable would reduce the dimensionality of the problem from 3N to 3, thus drastically simplifying quantum mechanical calculations. This is in fact possible, and it is the goal of orbital-free density functional theory (OF-DFT). For a system of N electrons in an external potential Vext, the total energy E can be expressed as a functional of the density ρ [1], taking on the following form: $$ E\left[ \rho \right] = F\left[ \rho \right] + \mathop \smallint \limits_\Omega V_{ext} \left( {\overrightarrow r } \right)\rho \left( {\overrightarrow r } \right)d\overrightarrow r $$ (1) Here, Ω denotes the system volume considered, while F is the universal functional that contains all the information about how the electrons behave and interact with one another. The actual form of F is currently unknown and one has to resort to approximations in order to evaluate it. Traditionally, it is split into kinetic and potential energy contributions, the exact forms of which are also unknown.
Model-Integrated Development of Cyber-Physical Systems

Cyber-physical systems represent a new class of systems that integrate physics with computation. Their correct design is frequently of great importance as they are applied in safety- or business-critical contexts. This paper introduces a model-integrated development approach that addresses the development needs of such systems through the pervasive use of models. A complete model-based view is proposed that covers all aspects of the hardware and software components, as well as their interactions. Early experiments and work in progress are also reported.
The Role of a Natural Language Conversational Interface in Online Sales: A Case Study

This paper describes the evaluation of a natural language dialog-based navigation system (HappyAssistant) that helps users access e-commerce sites to find relevant information about products and services. The prototype system leverages technologies in natural language processing and human-computer interaction to create a faster and more intuitive way of interacting with websites, especially for less experienced users. The result of a comparative study shows that users prefer the natural language-enabled navigation two to one over the menu driven navigation. In addition, the study confirmed the efficiency of using natural language dialog in terms of the number of clicks and the amount of time required to obtain the relevant information. In the case study, as compared to the menu driven system, the average number of clicks used in the natural language system was reduced by 63.2% and the average time was reduced by 33.3%.
Objects at their best: introductory applet programming and the Java AWT

This workshop will introduce the Java Abstract Window Toolkit. We will provide a simple framework for applet development that encompasses placement of components, display of graphical elements, and event handling. We will also introduce the Model-View-Control paradigm and apply it to the applet context, thereby bringing an important tool from object-oriented methodology to this area and laying the foundation for a study of the newer Java Swing package. Participants should be familiar with the Java programming language, though presumaly not the AWT. In addition, some familiarity with object-oriented language concepts including classes, methods, messages, inheritance, interfaces, and polymorphism (method overriding) is required.
Market Imperfections, Macroeconomic Conditions, and Capital Structure Adjustments

This paper investigates how capital structure dynamics depend on “systematic” adjustment costs proxied by market imperfections and macroeconomic conditions in a cross-country setting. We document substantial variations in firms’ capital structure adjustments across countries as well as over time. Consistent with adjustment costs impeding firms from rebalancing their capital structures, worse market imperfections are associated with slower speeds of adjustment (SOA) and larger leverage deviations. Intertemporally, capital structure adjustment is procyclical, with SOA increasing by 0.9 percentage point for every one-percentage-point increase in GDP growth. The procyclicality is attributable to good macroeconomic conditions mitigating market imperfections through channels of 1) facilitating free-ride restructuring, and 2) uncertainty alleviation. Our investigation features a bootstrapping-based estimation method that addresses the mechanical mean reversion of leverage ratio.
Precision studies of the 3,4He(e,e′p) reactions at MAMI

Precision studies of the reactions 3,4 He(e,e′p) in quasi-elastic kinematics are presented. Absolute cross-sections were measured at three virtual photon polarizations for the two-body-breakup channels as well as for the missing energy continuum. For the measured missing momentum range up to 100–150 MeV/c, no strength is observed for missing energies higher than 20 MeV and 45 MeV for 3 He and 4 He , respectively. Momentum distributions were extracted for all excitation energy regions. The longitudinal and transverse response functions were extracted using the Rosenbluth separation technique. The longitudinal and transverse nature of the cross-sections is described well by the cel prescription of the off-shell electron-nucleon cross-section. The results are compared to modern calculations for few-body nuclear systems. These measurements constitute part of an extensive program at MAMI to study the 3,4 He(e,e′p) reaction systematically over a wide range of kinematics.
Endoscopic approach to the orbital apex and periorbital skull base.

Objectives/Hypothesis: To review cases of endoscopic orbital apex and periorbital skull base surgery and stratify the pathology and lesion location. Variations in surgical technique and the outcomes are reviewed. We report the results of all cases of endoscopic orbital apex surgery over a 40-month period. Eighteen cases with a variety of pathology, location in the orbital apex, and surgical technique are reviewed. Study Design: Retrospective chart review. Methods: All cases of endoscopic orbital apex and periorbital skull base surgery over a 40-month period were reviewed. Lesion location, surgical approach, pathology, and postoperative complications are summarized. The details of the technique as well as limitations and advantages of this approach are summarized. Results: Eighteen patients who underwent endoscopic orbital apex surgery were identified. Eleven (61%) of the patients were men, and the average age was 51 years. The majority of lesions, 12 (67%), were located in the medial orbit and/or optic canal, two (11%) in the cavernous sinus and/or superior orbital fissure, and four (22%) in the inferior orbit and/or pterygopalatine fossa. The etiologies were diverse, including benign (44%), malignant (28%), infectious (11%), and inflammatory (17%). The majority of cases, 67%, were approached by the transnasal endoscopic technique followed by 28% with a combined transnasal and transcaruncular approach, and 6% by the sublabial approach. Complications occurred in 22% of cases. Conclusions: Conventional orbitotomy techniques and craniotomy are frequently used to access lesions in the orbital apex. The more recently described endoscopic technique with intraoperative image guidance can provide access to a subset orbital apical and periorbital skull base lesions. In carefully selected cases, this technique provides excellent visualization and access to the orbital apex and avoids larger craniofacial surgeries. Laryngoscope, 2011
Global hormone profiling of murine placenta reveals Secretin expression

Objective To elucidate and categorize the murine placental hormones expressed across gestation, including the expression of hormones with previously undescribed roles.
Treatment of adults with progressive oligodendroglioma with carboplatin (CBDCA): Preliminary results

Background. Exploration of the role of chemotherapy in the treatment of low grade glioma, including oligodendroglioma, has been limited to the pediatric population, reflecting the sensitivity of young patients to radiation-induced toxicity and a desire to avoid this intervention (7-12). Procedure. Nine adults with progressive oligodendroglioma were treated with carboplatin at a dose of 560 mg/m 2 administered at 4 week intervals. Results. Eight patients have demonstrated stable disease as determined by serial MRI imaging at 2-3 month intervals with neither tumor regression nor growth noted. The ongoing duration of tumor control ranges between 6-22 months. Three patients have completed therapy with carboplatin and continue with stable dis-ease off chemotherapy. One patient progressed after 1 year of therapy with histologic confirmation of growth of well differentiated oligodendroglioma. Toxicity was limited to grade 3 thrombocytopenia in 3 patients and grade 3 neutropenia in 2 patients. Conclusions. Carboplatin appears to be active in the treatment of adults with progressive oligodendroglioma. Further trials are warranted to more precisely define the role of carboplatin in the treatment of these tumors.
Purification of isoleucyl transfer ribonucleic acid synthetase by affinity chromatography on blue dextran—Sepharose

The aminoacyl-tRNA synthetases are a family of twenty enzymes that function in the first step of protein biosynthesis by esterifying the twenty amino acids to their cognate tRNAs [l] , Purification procedures for these enzymes are generally long and laborious. Recently several affinity chromatographic methods have been reported. Several of the aminoacyltRNA synthetases have been purified utilizing columns of purified, immobilized tRNA [2-5 ] . A method for purification of isoleucyl-tRNA synthetase (IRS) involves the use of Lisoleucinyl 5’-adenylate, an aminoacyl-AMP analog, as the insoluble ligand [6]. Unfortunately, the preparation of these column materials is generally laborious, often expensive, and may yield chromatographic media of limited stability suitable only for small scale preparations. Stellwagen [7] has reported that blue dextran linked to Sepharose may be used as an affinity chromatographic medium for many proteins which bind dinucleotides and ATP. Because the material is easily synthesized and stable, we have studied its potential as an affinity chromatographic medium for the purification of aminoacyl-tRNA synthetases. We now report the purification of IRS of Escherichia coli (EC 6.1.1.5) to near-homogeneity from crude cellular extracts by chromatography on two sequential blue dextranSepharose columns.
Optimizing the number of tests for carpal tunnel syndrome.

The combined sensory index (CSI), the sum of three latency differences, median-ulnar across the palm (palmdiff), median-ulnar to the ring finger (ringdiff), and median-radial to the thumb (thumbdiff), has higher sensitivity and reliability for carpal tunnel syndrome than individual tests. The objective in this study was to develop an approach that minimizes testing but maximizes accuracy. We retrospectively studied 300 hands. There were endpoints for individual tests that confidently predicted the CSI; for ranges between these endpoints, further testing was required. These ranges were: palmdiff 0–0.3 ms; ringdiff 0.1–0.4 ms; and thumbdiff 0.2–0.7 ms. One may use a strategy in which more tests are performed when results are in these ranges. This approach can allow accurate diagnosis with fewer tests when values are extreme, yet uses the greater diagnostic power of more tests when values are midrange. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 1880–1882, 2000
All-pairs shortest-paths for large graphs on the GPU

The all-pairs shortest-path problem is an intricate part in numerous practical applications. We describe a shared memory cache efficient GPU implementation to solve transitive closure and the all-pairs shortest-path problem on directed graphs for large datasets. The proposed algorithmic design utilizes the resources available on the NVIDIA G80 GPU architecture using the CUDA API. Our solution generalizes to handle graph sizes that are inherently larger then the DRAM memory available on the GPU. Experiments demonstrate that our method is able to significantly increase processing large graphs making our method applicable for bioinformatics, internet node traffic, social networking, and routing problems.
Surgical drains can be safely avoided in lateral neck dissections for papillary thyroid cancer.

Abstract Background Drains are widely used in lateral neck dissections (LNDs). Our objective was to compare outcomes of LNDs for papillary thyroid cancer (PTC) with and without drains. Methods One hundred sixty-five LNDs in 129 patients operated on from July 2001 to October 2008 were analyzed retrospectively. LNDs were divided according to the number of excised lymph nodes as follows: group A median. Further categorization was based on the use of a drain. Main outcome measures were wound complications requiring intervention. Results One hundred two LNDs were performed with a drain and 63 without. The overall rate of wound complications was 3%. There was no significant difference in complication rate between the drain and the non-drain group (group A: 1.8% vs 0; group B: 2.2% vs 7.9%, respectively). Conclusions Significant seromas/hematomas are rare complications of LNDs. Patients who undergo LND for PTC without a drain show no significantly increased rate of these complications.
Sedimentary record of the Late Cretaceous thrusting and collapse of the Salinia-Mojave magmatic arc

Upper Cretaceous conglomerates in the Gualala basin, California, contain rhyolite and granite clasts that have been previously hypothesized to have disparate terranes of origin. New geochemical, age, and isotopic analyses of these conglomerate clasts suggest an igneous origin in the upper levels of the continental side of the Cretaceous Cordilleran magmatic arc. Sr-Nd isotope relations constrain a provenance in the pre-Neogene Salinia-Mojave arc segment. Given the tectonically reconstructed outboard depositional location for the Gualala basin, we interpret the initiation of rhyolite-granite conglomerate deposition in the Gualala basin to reflect the arrival of the westward-thrusted Salinian allochthon at the forearc, coincident with the collapse of the Salinia-Mojave segment of the magmatic arc. This interpretation constrains the age of batholithic collapse to be ca. 80 Ma and suggests that thrusting immediately followed or may have been contemporaneous with the youngest magmatic events in this part of the arc. The data do not support contributions from a northward-moving Baja British Columbia (Baja BC) terrane, or large-scale translation (∼2000 km) of the basin.
Distinguishing fault reactivation from flexural deformation in the distal stratigraphy of the Peripheral Blountian Foreland Basin, southern Appalachians, USA

Reactivation of intraplate structures and weak zones within the foreland lithosphere disrupt the modelled geometry and pattern of migration of the flexural wave in foreland basins. In the southern Appalachians (USA), the Middle Ordovician unconformity, irregular Middle Ordovician distal foreland deposition and backstepping of Middle–lower Upper Ordovician carbonate strata have been related to migration of the flexural wave. However, integration of stratigraphy, tectonic subsidence history and composition of palinspastically restored distal foreland strata, using a map of subsurface basement structures as reference, allows us to distinguish an early event of inversion from two events of flexural migration. Sections restoring at very short distances outside the boundaries of a former basement graben have the youngest passive-margin strata preserved beneath Middle Ordovician (∼466 Ma) peritidal to deep lagoonal carbonates with gravel-size chert clasts. In contrast, sections restoring inside the graben record >470 m of truncation of pre-Middle Ordovician passive-margin strata, late onset of deposition (∼456 Ma), and subaerial features in carbonate and siliciclastic strata. The lacuna geometry and early patterns of distal foreland uplift and carbonate deposition indicate that inversion of a basement graben in response to Middle Ordovician convergence, rather than a migrating or semi-fixed forebulge, was the primary control on the early evolution of the distal foreland. Drowning of the carbonate platform in more proximal settings, northeastward onset of deposition on upthrown blocks, and thick accumulation of carbonates in downthrown blocks record northwestward and northeastward flexural wave migration at the Middle–Late Ordovician boundary. In early Late Ordovician, the overall shoaling of carbonate and siliciclastic depocentres and the rise of tectonic subsidence curves indicate hinterlandward migration of flexural uplift. Both events of flexural migration were accompanied by influx of volcanic ash and synorogenic sediments.
POSTMATING-PREZYGOTIC ISOLATION IS NOT AN IMPORTANT SOURCE OF SELECTION FOR REINFORCEMENT WITHIN AND BETWEEN SPECIES IN DROSOPHILA PSEUDOOBSCURA AND D. PERSIMILIS

Most work on adaptive speciation to date has focused on the role of low hybrid fitness as the force driving reinforcement (the evolution of premating isolation after secondary contact that reduces the likelihood of matings between populations). However, recent theoretical work has shown that postmating, prezygotic incompatibilities may also be important in driving premating isolation. We quantified premating, postmating-prezygotic, and early postzygotic fitness effects in crosses among three populations: Drosophila persimilis, D. pseudoobscura USA (sympatric to D. persimilis), and D. pseudoobscura Bogota (allopatric to D. persimilis). Interspecific matings were more likely to fail when they involved the sympatric populations than when they involved the allopatric populations, consistent with reinforcement. We also found that failure rate in sympatric mating trials depended on whether D. persimilis females were paired with D. pseudoobscura males or the reverse. This asymmetry most likely indicates differences in discrimination against heterospecific males by females. By measuring egg laying rate, fertilization success and hatching success, we also compared components of postmating-prezygotic and early postzygotic isolation. Postmating-prezygotic fitness costs were small and not distinguishable between hetero- and conspecific crosses. Early postzygotic fitness effects due to hatching success differences were also small in between-population crosses. There was, however, a postzygotic fitness effect that may have resulted from an X-linked allele found in one of the two strains of D. pseudoobscura USA. We conclude that the postmating-prezygotic fitness costs we measured probably did not drive premating isolation in these species. Premating isolation is most likely driven in sympatric populations by previously known hybrid male sterility.
Pyrethroids of the most potent class antagonize GABA action at the crayfish neuromuscular junction.

Abstract Deltamethrin and three insecticidal cyano analogs causing the Type II pyrethroid syndrome increased the input resistance of crayfish claw opener muscle fibers bathed in γ-aminobutyric acid (GABA). In contrast, two non-toxic stereoisomers and three insecticidal pyrethroids causing the Type I syndrome were inactive. Known GABA antagonists including picrotoxinin (PTX) induced an effect similar to, although quicker than, that caused by the active pyrethroids. Two benzodiazepines reduced the potency of PTX and deltamethrin. Cyanophenoxybenzyl pyrethroids therefore appear to act on the GABA receptor-ionophore complex.
Nonlinear and three-wave resonant interactions in magnetohydrodynamics

Hamiltonian and variational formulations of equations describing weakly nonlinear magnetohydrodynamic (MHD) wave interactions in one Cartesian space dimension are discussed. For wave propagation in uniform media, the wave interactions of interest consist of (a) three-wave resonant interactions in which high-frequency waves may evolve on long space and time scales if the wave phases satisfy the resonance conditions; (b) Burgers self-wave steepening for the magnetoacoustic waves, and (c) mean wave field effects, in which a particular wave interacts with the mean wave field of the other waves. The equations describe four types of resonant triads: slow–fast magnetoacoustic wave interaction, Alfven–entropy wave interaction, Alfven–magnetoacoustic wave interaction, and magnetoacoustic–entropy wave interaction. The formalism is restricted to coherent wave interactions. The equations are used to investigate the Alfven-wave decay instability in which a large-amplitude forward propagating Alfven wave decays owing to three-wave resonant interaction with a backward-propagating Alfven wave and a forward-propagating slow magnetoacoustic wave. Exact solutions of the equations for Alfven–entropy wave interactions are also discussed.
A review of ground-based heavy-ion radiobiology relevant to space radiation risk assessment. Part II: Cardiovascular and immunological effects

The future of manned space flight depends on an analysis of the numerous potential risks of travel into deep space. Currently no radiation dose limits have been established for these exploratory missions. To set these standards more information is needed about potential acute and late effects on human physiology from appropriate radiation exposure scenarios, including pertinent radiation types and dose rates. Cancer risks have long been considered the most serious late effect from chronic daily relatively low-dose exposures to the complex space radiation environment. However, other late effects from space radiation exposure scenarios are under study in ground-based accelerator facilities and have revealed some unique particle radiation effects not observed with conventional radiations. A comprehensive review of pertinent literature that considers tissue effects of radiation leading to functional detriments in specific organ systems has recently been published (NCRP National Council on Radiation Protection and Measurements, Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, Report 153, Bethesda, MD, 2006). This paper highlights the review of two non-cancer concerns from this report: cardiovascular and immunological effects.
Marketing and Recruiting in Urban Magnet Schools Implications for Change in School-Community Relations

Magnet schools' "marketing" and recruitment takes several forms and has important side effects.
Time of Emergence of Turkey Embryos

Abstract Abbott and Craig (1960) reported that turkey embryos exhibit greater variation in the amount of time from pipping to emergence than either pheasants or quail. Those who are concerned with the hatching of turkey eggs are quite aware of the wide differences in hatch time of this species. This is a report of a study designed to examine more closely emergence time in turkey embryos and its relation to subsequent poult performance. Eggs from a trapnested Broad Breasted Bronze flock were held for 15 days at 12.5°C. (55°F.) prior to setting. They were placed in the incubator so that the proper incubator temperature was reached at 4 p.m. on the day set. Beginning at 624 hours from this point, and at 8-hour intervals thereafter up to 680 hours, the incubator was opened for appropriate observations on emergence from the egg. A total of 4 hatches were examined from January to…
Gating Union: The Politics of Making a Historically Black Community

ABSTRACTIn 1999, Union was officially recognized as a Historic District by the National Register of Historic Places. Although approximately 80 percent of the residents are raced white, Union was identified as a historically black space. The recognition, premised on Union's origins as a town founded by freed slaves in the late nineteenth century, was the culmination of efforts by the Union Community Association. Its members, who are predominantly white, middle class, and newcomers to the area, took on the role of “protecting” their community by gaining official historic recognition, a task that established them as the gatekeepers of history, and black residents as historical artifacts. As Union became established as a historically black community, its social and legal boundaries could act to protect the place against unwanted land developers. While (white) residents took on the role as history's gatekeepers, (black) descendent residents were turned into tangible metonyms for history, authenticating by thei...
Is there a Unique Conformation of Cholinergic Ligands responsible for Muscarinic Activity

CHOTHIA1 has proposed a structure activity relationship for the muscarinic response of acetylcholine. In deriving the model responsible for optimum activity, reports on the pharmacological testing of a number of conformationally constrained acetylcholine analogues were neglected.
Estimating Monotonic Functions and Their Bounds

A function estimator MSQUID is presented for fitting and bounding noisy data that are known to be monotonic. MSQUID augments a “backpropagation” neural network model with a set of constraints which restricts the model to monotonic functions. Model parameters are estimated using nonlinear, constrained optimization at little increase in computation over standard neural networks. It is proven that MSQUID can estimate any monotonic function and produces more accurate estimates than unconstrained optimization. These monotonic functions and their confidence bounds can be used in many fault detection and diagnosis systems.
Self-organizing distributed sensor networks

Advances in CMOS IC and micro electrical-mechanical systems (MEMS) technologies are enabling construction of low-cost building blocks each of which incorporates sensing, signal processing, and wireless communications. Collections of these integrated microsensor nodes may be formed into sensor networks in a wide variety of ways, with characteristics that depend on the specific application--the total number of nodes, the spatial density, the geometric configuration (e.g., linear vs. areal), topographic aspects (e.g., smooth vs. rough terrain), and proximity and proportion of user/sink points. The power of these distributed sensor networks will be unleashed by means of their ability to self-organize, i.e., to bootstrap and dynamically maintain organizational structure befitting the purpose and situation that is presented, without the need for human assistance. A prototype sensor system and networking protocols are being developed under the DARPA/TTO AWAIRS Program and are described.
Coal sample preservation in foil multilaminate bags

Abstract An initial 1-year study on a bituminous coal sample indicated that storage under argon in heat-sealed 0.20-mm thick bags of laminated polyethylene, aluminum foil, and fibrous polyethylene preserved initial sample properties better than conventional containers already in use. Continuation of the study over 14 years showed that this storage protocol preserves that sample's initial properties very well. A 2-year comparison to samples in flame-sealed glass ampoules showed comparable ability to preserve thermoplastic behavior. Thirty-three samples in the Penn State Coal Sample Bank, collected since 1989 for the “Department of Energy Coal Sample” (DECS) series, are stored under argon at 3 °C in these bags. Selected samples from this series have been analyzed periodically for up to 13 years; for the majority of the samples, moisture, sulfate sulfur, and calorific value were maintained within ASTM reproducibility limits over the term of the tests. Gieseler fluid behavior (for samples of appropriate rank) was maintained within the more narrow repeatability limits for at least several years. In some cases, trends suggest that the initial properties will be maintained indefinitely. An 8-year comparison of refrigerated to unrefrigerated storage has not yet shown significant differences.
Progress towards commercialization of plastid transformation technology

Tobacco chloroplasts are ready to be tested as a platform for the expression of recombinant proteins on a commercial scale. They hold the promise of reproducible yields of 5–25% of total soluble cellular protein in leaves and reliability has been achieved through refinement of an expression toolkit that includes vectors, recently developed expression cassettes and systems for marker gene removal. Implementation of plastid transformation technology in other crops, however, has met with difficulty and has delayed agronomic applications.
COMPARATIVE REPRODUCTIVE BIOLOGY OF HERMAPHRODITIC AND MALE‐STERILE IRIS DOUGLASIANA HERB. (IRIDACEAE)

A comparative study of the reproductive biology of male-sterile and hermaphroditic plants in a gynodioecious population of Iris douglasiana Herb. (Iridaceae) was conducted at the University of California's Marine Laboratory at Bodega Bay, California, between 1976-1979. Each year of the study, there were 11.1% male-sterile plants in the population, some of which began blooming at the same time as the earliest blooming hermaphrodites. Male-sterile flowers made up between 7-21% of the flowers produced during the male-sterile flowering period. Male-sterile flowers had smaller sepals and petals than hermaphrodites, there were fewer of them per square meter, and they had fewer pollinated stigmas than did hermaphroditic flowers. In a test to determine pollinator preference, intact hermaphroditic flowers tended to have more pollinated stigmas than did hermaphrodites with their stamens removed or those flowers with shortened sepals made to resemble the smaller male-sterile flowers. Floral phenology and nectarflow patterns were similar in both types of flowers as were the kinds of amino acids and sugar rewards in the nectar. Male-sterile flowers, however, produced much less nectar per flower. There were no significant differences in the number of ovules per flower or the number of seeds produced per capsule between the two flower types, but the loss of seeds through larval predation was much greater in capsules from hermaphroditic flowers. Early flowering and setting of seed by plants with male-sterile flowers could give them a reproductive advantage over plants with hermaphroditic flowers which experience higher levels of larval predation later in the growing
Measurement of the transmission and reflection Mueller matrices of a thin blood column

The extinction of light passing through a blood vessel comprises both absorbed and scattered components, the latter of which includes relatively strong forwardly transmitted and directly reflected components. The effect of such vessels on incident light beams of arbitrary polarization is most thoroughly described by the vessel's transmission and reflection Mueller matrices. The Mueller matrices of illuminated mock blood vessels (diameter 102-278 micrometers ) in these two important directions have been measured at a wavelength of 633 nm using a Mueller matrix imaging polarimeter. The measured Mueller matrices are presented, decomposed, and analyzed to determine the sample's retardance and depolarization as a function of vessel diameter. It is expected that characterization of these matrices should broaden light-vessel modeling techniques by permitting calculation of the transmitted and reflected properties of arbitrary input polarization states.
Women and Political Participation

IntroductionThis essay focuses on three questions: Why are so few women elected to public office in the United States? What theories might best explain that? Are the theories that explain patterns of women's office holding in one country useful in explaining patterns of office holding in other nations?
Efficient catalytic plasma activation of CO2, NO, and H2O

The activation of small molecules, such as CO2, NO, and H2O, has been achieved at atmospheric pressure via ac glow discharge methods in the presence of metal catalysts coated onto the electrode surfaces. A fan-type reactor having one rotating and one static electrode has been designed to diminish mass transfer effects. Time lapse photography of the emitting plasma intermediate species and optical emission studies have been used to monitor reaction pathways. Gas chromatography, mass spectrometry, and combined GC−MS methods have been used to monitor product distributions, selectivities, and activities. The effects of flow rate, input voltage, diluent gases, and metal coating have been systematically studied. Additionally, the mechanisms of CO2 decomposition and the role of the metal catalyst in that decomposition have been studied by optical emission spectroscopy.
Procedural or Conceptual Training: Which is Better for Teaching Novice Pilots Landings and Traffic Patterns?:

Forty-eight student pilots and recently licensed private pilots were randomly assigned to one of three training groups: procedural, conceptual, and control. Participants in the procedural group spent approximately two hours reading text and watching videos specific to the step-by-step procedures of how to fly traffic patterns and land an airplane. Participants in the conceptual group spent approximately two hours reading reasoning explanations, everyday metaphors to aviation, and viewing diagrams of traffic patterns and landings. Participants in the control group spent approximately two hours watching aviation-themed videos and reading aviation-themed text, but unrelated to traffic patterns, landings, or any other flight task. During training, participants answered questions specific to the material they were reading or watching. At the conclusion of the training participants were tested on typical and atypical traffic pattern performance, typical and atypical landing performance, and routine and non rout...