cssi/SciSciGPT-SciSciNet huggingface dataset:
E-043 Reversible Cerebral Vasoconstriction Syndrome: Non-invasive Imaging Findings and Angiographic Evaluation

Purpose Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a transient disorder of cerebral arterial auto regulation that may have a non-specific clinical presentation, most typically initiating as an acute episode of severe (thunderclap) headache. The clinical scenario and the non-invasive imaging findings are similar to those seen in more common pathologies making it a challenging diagnosis if the entity is not a consideration in the initial evaluation. RCVS presentation and initial imaging findings may mimic a ruptured aneurysm, stroke, migraine and posterior reversible encephalopathy syndrome, among others. Our aim is to describe the entity of RCVS and demonstrate the common and uncommon imaging findings seen on CT, MRI, CT angiography, with emphasis on conventional digital subtraction arteriogram pre and post endovascular treatment. Approach/methods A multimodality pictorial review of cases from our institution is presented, including non-contrast head CT, CT angiogram, MRI, MR angiogram and conventional digital subtraction arteriogram (DSA). Diagnosis of RCVS was confirmed by imaging demonstration of reversibility of arterial constriction on follow-up imaging or after intra-arterial therapy. Findings/discussion We present indirect findings on non-invasive imaging, such as transient cerebral edema, convexal subarachnoid hemorrhage, intraparenchymal hemorrhage and cerebral. Direct signs of single or multivessel arterial vasoconstriction are seen on CTA, MRA and confirmed on DSA. Reversibility of the vasoconstriction is demonstrated after intra-arterial administration of calcium channel blocker. Conditions such as diffuse atherosclerotic arterial narrowing, vasculitis, posterior reversible encephalopathy, cerebral edema secondary to venous congestion and vasospasm secondary to aneurysmal subarachnoid hemorrhage were among the pathologies considered prior to a definitive diagnosis of RCVS. Summary/conclusion Familiarity with the imaging findings of RCVS is of critical importance to direct appropriate and timely clinical management. Atypical subarachnoid hemorrhage, unexplained cerebral edema and hemorrhage, as well as single or multivessel diffuse narrowing with a relatively normal appearing brain should raise suspicion of RCVS. Suspicion can be confirmed by demonstrating the reversibility of vasoconstrictions after intra-arterial administration of calcium channel blocker or at follow-up imaging. Disclosures K. de Macedo Rodrigues: None. R. Hito: None. D. Takhtani: None. J. Lozano: None. A. Wakhloo: 1; C; NIH, Philips Healthcare, Wyss Institute. 2; C; Codman Neurovascular and Stryker Neurovascular. 4; C; co-founder of InNeuroCo Inc. and major stockholder; stocks in EpiEB and Pulsar Medical. 6; C; speaker: Harvard Postgraduate Course, Miami Cardiovascular Institute. A. Puri: 1; C; Stryker Neurovascular and Covidien. 2; C; Codman Neurovascular, Stryker Neurovascular and Covidien. 4; C; InNeuroCo Inc. 6; C; speaker: Miami Cardiovascular Institute.
Bayesian Baskets: A Novel Design for Biomarker-Based Clinical Trials

Purpose Biomarker-based clinical trials provide efficiencies during therapeutic development and form the foundation for precision medicine. These trials must generate information on both experimental therapeutics and putative predictive biomarkers in the context of varying pretrial information. We generated an efficient, flexible design that accommodates various pretrial levels of evidence supporting the predictive capacity of biomarkers while making pretrial design choices explicit. Methods We generated a randomization procedure that explicitly incorporates pretrial estimates of the predictive capacity of biomarkers. To compare the utility of this Bayesian basket (BB) design with that of a balanced randomized, biomarker agnostic (BA) design and a traditional basket (TB) design that includes only biomarker-positive patients, we iteratively simulated hypothetical multiarm clinical trials under various scenarios. Results BB was more efficient than BA while generating more information on the predictive capacity of putative biomarkers than both BA and TB. For simulations of hypothetical multiarm trials of experimental therapies and associated biomarkers of varying incident frequency, BB increased power over BA in cases when the biomarker was predictive and when the experimental therapeutic worked in all patients in a variety of scenarios. BB also generated more information about the predictive capacity of biomarkers than BA and categorically relative to TB, which generates no new biomarker information. Conclusion The BB design offers an efficient way to generate information on both experimental therapeutics and the predictive capacity of putative biomarkers. The design is flexible enough to accommodate varying levels of pretrial biomarker confidence within the same platform structure and makes clinical trial design decisions more explicit.
Effect of overlap orientation on fatigue behavior in friction stir linear welds of magnesium alloy sheets

Abstract In this work, we investigate the effect of sheet stacking orientation on fatigue behavior in friction stir linear welding of AZ31 Mg alloy. It is well known that during friction stir welding, the advancing and retreating flow of the material generated by the tool creates asymmetrical weld features resulting is anisotropic mechanical behavior. As such, friction stir welding of overlap joints was carried out on 2 mm thick sheets, where the orientation of the pull direction of the coupon was varied with respect to the tool rotation direction. Subsequently experimental fatigue tests were performed to evaluate this effect of the sheet stacking orientation on cyclic behavior. The fatigue results showed that the overlap joints loaded on the retreating side exhibited superior performance compared to the advancing side. Post-mortem analysis coupled with finite element results suggest that the geometrical shape of the faying surface produced by the advancing and retreating material flow largely determines the number of cycles to failure in these friction stir linear welded overlap joints.
Reward/Penalty Design in Demand Response for Mitigating Overgeneration Considering the Benefits from both Manufacturers and Utility Company

Abstract The high penetration of renewable sources in electricity grid has led to significant economic, environmental, and societal benefits. However, one major side effect, overgeneration, due to the uncontrollable property of renewable sources has also emerged, which becomes one of the major challenges that impedes the further large-scale adoption of renewable technology. Electricity demand response is an effective tool that can balance the supply and demand of the electricity throughout the grid. In this paper, we focus on the design of reward/penalty mechanism for the demand response programs aiming to mitigate the overgeneration. The benefits for both manufacturers and utility companies are formulated as the function of reward and penalty. The formulation is solved using particle swarm optimization so that the benefit from both supply side can be maximized under the constraint the benefit of customer side is not sacrificed. A numerical case study is used to verify the effectiveness of the proposed method.
Spinning magnet antenna for VLF transmitting

If we spin or wiggle a permanent magnet, it acts like an electrically small loop antenna, generates electromagnetic wave. In this paper we present our study on a spinning magnet antenna for VLH transmitting. Based on our simulation study, a spinning magnet antenna array is proposed.
SO 2 quantification of rat HCC tumors using fluence-corrected photoacoustic imaging

Spectroscopic photoacoustic (sPA) can estimate blood oxygen saturation (SO 2 ), which has been shown to correlate with hypoxia, and therefore could improve cancer diagnosis and treatment monitoring. However, accurate quantification of SO 2 is often not straightforward as local fluence varies significantly at depth due to wavelength-dependent optical scattering and absorption. Additionally, assessing the quality of an SO2 estimate is not trivial as deep-lying (i.e., centimeter-order depth) PA data tends to be signal-limited, and SNR can vary substantially with wavelength for a particular voxel. This work implements an SNR-based thresholding approach combined with FEM-based local fluence correction to more accurately estimate SO 2 in a rat model of hepatocelluar carcinoma (HCC).
Technical note: known-component registration for robotic drill guide positioning

A method for x-ray-guided robotic positioning of surgical instruments is reported and evaluated in preclinical studies of spine pedicle screw placement with the aim of improving delivery of transpedicle drills and screws. The known-component registration (KC-Reg) algorithm was used to register the 3D patient CT and the surface model of a drill guide to intraoperatively acquired 2D radiographs. Resulting transformations, combined with offline hand-eye calibration, drive a robotically-held drill guide to target trajectories established in the preoperative patient CT. The proposed method was assessed against more conventional surgical tracker guidance, and robustness to clinically realistic errors was tested in phantom and cadaver studies. Target registration error (TRE) was computed as drill guide deviation from the planned trajectory. The KC-Reg approach resulted in 1.51 ± 0.51 mm error at tooltip and 1.01 ± 0.92° in approach angle, showing comparable performance to the tracker-guided approach. In cadaver studies with anatomical deformation, TRE of 2.31 ± 1.05 mm and 0.66 ± 0.62° were observed, with statistically improved performance over a surgical tracker through registration of locally rigid bony anatomy. X-ray guidance offers an accurate means of driving robotic systems that is compatible with conventional fluoroscopic workflow. Specifically, such procedures involve multi-planar fluoroscopic views that are qualitatively interpreted by the surgeon; the KC-Reg approach accomplishes this using the same multi-planar views to provide greater quantitative accuracy and valuable guidance and QA. The method was robust against anatomical deformation due to the radiographic scene’s local nature used in registration, presenting a potentially major surgical benefit.
An In Vitro Model for Tumor Progression in Murine Lymphoid Cells

Histopathological observations of the development of tumors have led to the concept that oncogenesis proceeds through the sequential acquisition of independent growth-related phenotypic characteristics (Foulds 1975). This process of tumor progression occurs through events involving the expression of specific genes affecting the regulation of cellular growth (recently reviewed in Weinberg 1985; Klein and Klein 1985; Bishop 1985). The requirement of two complementing oncogenes for the in vitro transformation of primary rat embryo firbroblasts provides a useful in vitro experimental model of tumor progression. Ha-ras (EJ) and v-myc or Ha-ras (T24) and E1A can act together to transform primary fibroblasts, while neither oncogene acting alone is capable of causing efficient transformation (Land et al. 1983; Ruley 1983) unless expressed at a high level (Spandidos and Wilkie 1984).
Embassies: radically refactoring the web

Web browsers ostensibly provide strong isolation for the client-side components of web applications. Unfortunately, this isolation is weak in practice; as browsers add increasingly rich APIs to please developers, these complex interfaces bloat the trusted computing base and erode cross-app isolation boundaries. We reenvision the web interface based on the notion of a pico-datacenter, the client-side version of a shared server datacenter. Mutually untrusting vendors run their code on the user's computer in low-level native code containers that communicate with the outside world only via IP. Just as in the cloud datacenter, the simple semantics makes isolation tractable, yet native code gives vendors the freedom to run any software stack. Since the datacenter model is designed to be robust to malicious tenants, it is never dangerous for the user to click a link and invite a possibly-hostile party onto the client.
Visualizing History in the Classroom: A Faculty-Librarian Partnership in the Digital Age.

AbstractProductive, equitable, and reciprocal librarian-faculty partnerships are difficult to establish for a range of reasons. This case study describes a long-term collaboration between a Digital...
On the Sum-Capacity-Achieving Distributions and Sum-Capacity of 1-Bit ADC MACs in Rayleigh Fading

This work addresses the sum-capacity-achieving signaling schemes and the sum-capacity of a multiple access channel (MAC) with two mobile users communicating to a base station equipped with 1-bit quantizers. We consider Rayleigh fading channels between the users and the base station where channel state information (CSI) is known only at the base station. Towards this end, we first establish a necessary and sufficient condition refereed to as Kuhn-Tucker condition (KTC) on the input distribution of one user for a given input signal used at another user so that the input/output mutual information (MI) is maximized. By relaxing the power constraint and establishing upper bounds on the MI, we demonstrate that the power constraint of the first user is active. Then using Fubini-Tonelli theorem to exchange the order of integrations between fading and input distributions, and exploiting novel bounds on the output distribution and a related relative entropy, it is shown that the optimal input distribution has a bounded amplitude. Due to the symmetry of the problem, it is then concluded that the sum-capacity-achieving amplitude distributions are bounded, and both users must use full power to achieve the sum-capacity. Next, we exploit the independence of the amplitude and phase of fading gains to show that the optimal inputs are π/2 circular symmetric. Building upon the results on the amplitude and phase, it is then demonstrated that any π/2 circular symmetric input distribution having a constant amplitude is sum-capacity achieving. The sum-capacity is finally obtained in a precise form.
Hepatitis B Vaccination and Waning Hepatitis B Immunity in Persons Living with HIV

Persons with HIV are at a higher risk for acquiring HBV (hepatitis B virus) than the general population due to shared modes of transmission and are significantly more likely to develop and die from sequelae of chronic HBV infection. Early vaccination is key to achieving HBV protective immunity, but response rates are still much lower than in the general population, ranging from 35 to 70%. Individuals with HIV also experience more rapidly waning immunity than those without HIV. Strategies to augment initial response and improve long-term immunity in individuals with HIV include alterations in dose, frequency, and the use of immune adjuvants. Recent studies have focused on the use of different vaccine formulations, the use of vaccine adjuvants, increased number and strength of vaccine dosages, increased dose frequency, alternative routes of administration, dual vaccinations, and the use of booster vaccines. Although no consensus has been reached on the use of certain vaccination regimens, three and four double-dose vaccine schedules via the intramuscular route have demonstrated higher initial response rates. Early vaccination when CD4 cell counts are greater than 350/mm3 with low viral loads has been shown to improve initial response, along with completion of immunization series. Adjuvants such as TLR4 and TLR9 agonists appear to improve response to HBV vaccination, but further research is needed in individuals with HIV. Persons with HIV have significant lower initial and long-term seroresponse rates after HBV vaccination than immunocompetent individuals. Recent and ongoing studies continue to evaluate multiple strategies to improve these rates within a uniquely susceptible population.
Design of a Volumetric Imaging Sequence Using a Vantage-256 Ultrasound Research Platform Multiplexed With a 1024-Element Fully Sampled Matrix Array

Ultrasound imaging using a matrix array allows real-time multi-planar volumetric imaging. To enhance image quality, the matrix array should provide fast volumetric ultrasound imaging with spatially consistent focusing in the lateral and elevational directions. However, because of the significantly increased data size, dealing with massive and continuous data acquisition is a significant challenge. We have designed an imaging acquisition sequence that handles volumetric data efficiently using a single 256-channel Verasonics ultrasound research platform multiplexed with a 1024-element matrix array. The developed sequence has been applied for building an ultrasonic pupilometer. Our results demonstrate the capability of the developed approach for structural visualization of an ex vivo porcine eye and the temporal response of the modeled eye pupil with moving iris at the volume rate of 30 Hz. Our study provides a fundamental ground for researchers to establish their own volumetric ultrasound imaging platform and could stimulate the development of new volumetric ultrasound approaches and applications.
Future Theories (Counterpoint Etc.)

The mathematical approach to music theory is specifically enabling new theories, theories of the future, of perspectives designing where to move.
Spontaneous recovery and the multiple timescales of human motor memory

In numerous paradigms, from fear conditioning to motor adaptation, memory exhibits a remarkable property: acquisition of a novel behavior followed by its extinction results in spontaneous recovery of the original behavior. A current model suggests that spontaneous recovery occurs because learning is supported by two different adaptive processes: one fast (high error sensitivity, low retention), and the other slow (low error sensitivity, high retention). Here, we searched for signatures of these hypothesized processes in the commands that guided single movements. We examined human saccadic eye movements and observed that following experience of a visual error, there was an adaptive change in the motor commands of the subsequent saccade, partially correcting for the error. However, the error correcting commands were expressed only during the deceleration period. If the errors persisted, the acceleration period commands also changed. Adaptation of acceleration period commands exhibited poor sensitivity to error, but the learning was resistant to forgetting. In contrast, the deceleration period commands adapted with high sensitivity to error, and the learning suffered from poor retention. Thus, within a single saccade, a fast-like process influenced the deceleration period commands, whereas a slow-like process influenced the acceleration period commands. Following extinction training, with passage of time motor memory exhibited spontaneous recovery, as evidenced by return of saccade endpoints toward their initial adapted state. The temporal dynamics of spontaneous recovery suggested that a single saccade is controlled by two different adaptive controllers, one active during acceleration, and the other during deceleration.
Ecological network inferred from field data elucidates invasion of a freshwater ecosystem by the exotic silver carp

Networks of interspecific interactions drive community structure, dynamics and stability. The ability to infer interspecies interactions from observational field data would open possibilities to apply network models to manage real world ecosystems. Here, we show this is possible for a freshwater fish community in the Illinois River, United States, using long-term data collected through time and space. We solve the challenge of sparsely sampled field data using latent variable regression and constraints imposed by known trophic structure in the fish community. Network analysis indicates that the most abundant 9 fish coexisted thanks to equalizing mechanisms that reduced fitness differences between strong and weak competitors. Importantly, the network sheds light on the ongoing invasion by the exotic silver carp (Hypophthalmichthys molitrix), revealing that the invader outproduces native preys, replacing their contributions to the diets of native predators. Our work shows that field data and constrains imposed by known food webs can improve network inference and produce quantitative insights that could aid in conservation of freshwater ecosystems threatened by invasive species.
On the impact of vessel wall stiffness on quantitative flow dynamics in a synthetic model of the thoracic aorta.

Aortic wall stiffening is a predictive marker for morbidity in hypertensive patients. Arterial pulse wave velocity (PWV) correlates with the level of stiffness and can be derived using non-invasive 4D-flow magnetic resonance imaging (MRI). The objectives of this study were twofold: to develop subject-specific thoracic aorta models embedded into an MRI-compatible flow circuit operating under controlled physiological conditions; and to evaluate how a range of aortic wall stiffness impacts 4D-flow-based quantification of hemodynamics, particularly PWV. Three aorta models were 3D-printed using a novel photopolymer material at two compliant and one nearly rigid stiffnesses and characterized via tensile testing. Luminal pressure and 4D-flow MRI data were acquired for each model and cross-sectional net flow, peak velocities, and PWV were measured. In addition, the confounding effect of temporal resolution on all metrics was evaluated. Stiffer models resulted in increased systolic pressures (112, 116, and 133 mmHg), variations in velocity patterns, and increased peak velocities, peak flow rate, and PWV (5.8–7.3 m/s). Lower temporal resolution (20 ms down to 62.5 ms per image frame) impacted estimates of peak velocity and PWV (7.31 down to 4.77 m/s). Using compliant aorta models is essential to produce realistic flow dynamics and conditions that recapitulated in vivo hemodynamics.
Repairing organs with MSC

Abstract Despite years of effort, the deceased donor renal allograft pool remains largely dependent upon the deceased by brain death (DBD) donor. The DBD population represents a small fraction of the deaths from traumatic injury each year. The majority of fatalities are never considered for organ donation because of severe ischemic injury occurring upon cardiac arrest outside of the controlled hospital environment. Even limited postmortem ischemia can result in a significant increase in the occurrence of delayed graft function that can pose the risk of primary nonfunction. A potential solution to the organ shortage is to combine the technology in the fields of regenerative medicine and tissue engineering to “repair” organs before transplant. Long-term ex vivo acellular warm perfusion is the foundation for achieving such regeneration. A potential component of this approach is the use of cell therapy to potentiate allograft regeneration. The goal will be to make a previously classified nontransplantable organ transplantable. Such an ambitious task must take into consideration any underlying renal disease, age of the donor, extent of the acute damage, and control complex sequences of biochemical events in repairing the damaged allograft. Regenerative processes rely in part on stem cells via their paracrine secretome or tissue-specific progenitor cells that can differentiate into cells replacing the damaged tissue. The stromal mesenchymal stem cell is relevant to the regeneration of ischemically damaged renal allografts because they do not integrate and do not pose the risk of increasing the immunogenicity of the graft. Progenitor renal epithelial cells are relevant to renal regeneration because they are the inherent progenitor that replaces lethally damaged renal epithelial cells. The ability to regenerate kidneys ex vivo sufficiently to result in immediate function could revolutionize transplantation by solving the chronic organ shortage.
New interpretations of the ages and origins of the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss, Adirondack Mountains, NY: Implications for the nature and timing of Mesoproterozoic plutonism, metamorphism, and deformation

Abstract The Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss are widespread Mesoproterozoic plutonic rocks that occur in the amphibolite- to granulite-facies Adirondack Highlands of northern New York, USA. The strongly deformed Hawkeye Granite Gneiss, previously dated by zircon multi-grain thermal ionization mass spectrometry (TIMS) U-Pb analyses at about 1100 Ma, was intruded by the weakly deformed Lyon Mountain Granite Gneiss. Previous sensitive high resolution ion microprobe (SHRIMP) analyses of Lyon Mountain Granite Gneiss zircon rims were considered to record the time of igneous emplacement at about 1.05 Ga, whereas the ages of zircon cores (~1.15 Ga) were interpreted as being inherited from nearby metaigneous country rocks. This interpretation has formed the basis of numerous models for the Mesoproterozoic structural and tectonic evolution of the Adirondacks Highlands. New U-Pb spot analyses (~15–20 µm diameter) by SHRIMP from four samples of Hawkeye Granite Gneiss and eight samples of Lyon Mountain Granite Gneiss challenge the historically accepted ages of the rocks. Using a combination of high-resolution CL imagery of oscillatory zoned cores and weakly zoned to unzoned rims, SHRIMP U-Pb geochronology, SHRIMP trace element geochemistry, and SEM petrography, we conclude that: (1) the Hawkeye Granite Gneiss was emplaced at about 1160–1155 Ma; (2) the vast majority of Lyon Mountain Granite Gneiss zircon cores yield ages of 1150–1145 Ma and are mainly primary, not inherited; and (3) the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss zircon rims (~1080–1000 Ma) are metamorphic in origin, not igneous. Thus, both the Hawkeye Granite Gneiss and Lyon Mountain Granite Gneiss are considered herein to be late members of the mangerite-charnockite-granite (MCG) plutonic suite, emplaced during the waning stages of the Shawinigan orogeny. Zircon cores from two small plutons of largely undeformed fayalite granite of the Lyon Mountain Granite Gneiss are about 1142 Ma, providing a minimum age constraint for the termination of the Shawinigan. Zircon rim ages can be deconvoluted into multiple metamorphic events of the Ottawan and Rigolet tectonothermal events. These new interpretations have profound implications for structural, tectonic, and ore deposit models of the Adirondacks Highlands.
Tamoxifen administration induces histopathologic changes within the lungs of Cre-recombinase-negative mice: A case report.

Tamoxifen is commonly used as a cancer treatment in humans and for inducing genetic alterations using Cre-lox mouse models in the research setting. However, the extent of tamoxifen off-target effec...
Origin of Cracking Phenomena Observed in Decomposition Reactions

Thermal decomposition, often referred to as calcination, is one of the important steps in ceramic processing. Decomposition reactions are of particular interest because they produce highly active solids of large surface areas1−3. But the high reactivity of fine powders is often limited by agglomeration and/or aggregation problems2,4. Furthermore large voids developed by cracking during the decomposition reaction can limit the densification of fine powders.
The Pseudomonas aeruginosa algC gene encodes phosphoglucomutase, required for the synthesis of a complete lipopolysaccharide core.

Abstract We have constructed strains of Pseudomonas aeruginosa with mutations in the algC gene, previously shown to encode the enzyme phosphomannomutase. The algC mutants of a serotype O5 strain (PAO1) and a serotype O3 strain (PAC1R) did not express lipopolysaccharide (LPS) O side chains or the A-band (common antigen) polysaccharide. The migration of LPS from the algC mutant strains in Tricine-sodium dodecyl sulfate-polyacrylamide gels was similar to that of LPS from a PAO1 LPS-rough mutant, strain AK1012, and from a PAC1R LPS-rough mutant, PAC605, each previously shown to be deficient in the incorporation of glucose onto the LPS core (K. F. Jarrell and A. M. Kropinski, J. Virol. 40:411-420, 1981, and P. S. N. Rowe and P. M. Meadow, Eur. J. Biochem. 132:329-337, 1983). We show that, as expected, the algC mutant strains had no detectable phosphomannomutase activity and that neither algC strain had detectable phosphoglucomutase (PGM) activity. To confirm that the PGM activity was encoded by the algC gene, we transferred the cloned, intact P. aeruginosa algC gene to a pgm mutant of Escherichia coli and observed complementation of the pgm phenotype. Our finding that the algC gene product has PGM activity and that strains with mutations in this gene produce a truncated LPS core suggests that the synthesis of glucose 1-phosphate is necessary in the biosynthesis of the P. aeruginosa LPS core. The data presented here thus demonstrate that the algC gene is required for the synthesis of a complete LPS core in two strains with different LPS core and O side chain structures.
A decoupling approach to the control of large spaceborne antenna systems

A simple practical method for designing antenna-feed positioning control systems for large deployable spaceborne antenna systems with flexible booms is proposed. The approach is based on the mechanical decoupling of the antenna-feed from the boom so that the positioning control system can be designed without taking boom dynamics into consideration, thus avoiding a complex infinite dimensional control problem. The basic idea is illustrated by a simple angular positional control system attached to a flexible boom restricted to torsional motion only. The application of this approach to more complex situations is discussed briefly.
To screen or not to screen

The theme editor introduces a special issue exploring the topic of medical screening and why tests are performed despite a lack of evidence that supports their benefit to patients. Virtual Mentor is a monthly bioethics journal published by the American Medical Association.
Genetic Discrimination: The Use of Genetically Based Diagnostic and Prognostic Tests by Employers and Insurers

Genetic discrimination is detrimental to public health programs, as well as to society generally. Advances in genetic testing and screening, accelerated and prompted by the Human Genome Initiative, increase society's ability to detect and monitor chromosomal differences. These technologies and their resulting genomic data will enhance medical science, but may also encourage discrimination. Although few employers or insurers currently utilize genetic screening, testing or data, rising employee benefit costs and market forces create powerful incentives for usage. Current municipal, state and federal laws, including the Americans with Disabilities Act (ADA), may not sufficiently protect employees and insureds from genetic discrimination. While municipal and state protections should not be overlooked, the ADA's sweeping scope may currently provide the most comprehensive safeguard. Federal laws banning discrimination on the basis of race or sex might also successfully redress some forms of genetic discrimination. Genetic technologies' advent necessitates efforts to rectify state and federal statutory coverage gaps, strictly regulate employers and produce comprehensive guidelines regarding its use.
Simple OS: a component-based operating system simulator in the spirit of the little man

Simple OS is a component-based operating system (OS) simulator designed to be customizable and easy to use. A key feature of the simulator is that users can write their own versions of the system components and use those components during OS execution. The simulator contains an easy-to-use graphical interface that presents visualizations of the internal works of the simulated OS. Users can view the contents of memory, partition information, paging information, CPU register values, process/job queues, process control blocks, process output, process program code (with and without symbols resolved), component information, and the OS activity log. Simple OS is designed to perform multitasking for a single-user. The system runs programs written in a proprietary pseudo-assembly language. Users can step through programs as they are executing, which is an important educational feature of the system. Simple OS makes the internals of the OS transparent to the user and promotes a greater understanding of how the components of an OS work together. Simple OS was created in order to address the problem of giving students hands-on experience writing OS code that is also manageable for them to complete.
Preschoolers' Emergent Literacy Skills: The Mediating Role of Maternal Reading Beliefs.

Research Findings: The purpose of this paper is to explore the association between maternal reading beliefs and children's emergent literacy outcomes in light of maternal education. Furthermore, I consider whether maternal reading beliefs may mediate the association between maternal education level and children's print knowledge and phonological awareness while classroom quality, maternal literacy practices, gender, and ethnicity are controlled. Data were collected from a socioeconomically diverse population of 92 mothers and their preschool children from 2 demographically different counties in a Mid-Atlantic state. Correlations among all measures were moderate and positive, with higher levels of maternal education associated with higher scores on a maternal beliefs measure and higher child scores on a print knowledge and phonological awareness measure. Maternal reading beliefs mediated the effects of maternal education level on children's print knowledge and phonological awareness. This pathway remained ...
Traditional signal pattern recognition versus artificial neural networks for nuclear plant diagnostics

Abstract This paper introduces a new tool based on a traditional noise analysis techniques for monitoring reactor components' signal condition. It also presents the performance of artificial neural networks for pattern recognition to the same set of reactor signals and provides a comparison of these two techniques. Reactor pump signals from the Experimental Breeder Reactor (EBR-II) are utilized here. Collected signals such as pump power, pump speed, and pump pressure are obtained from already installed sensors in the reactor. The signals utilized are collected signals as well as generated signals simulating the pump shaft degradation progress. From the study of time series analysis and regression modeling of these signals, a parameter related to degradation and material buildup in the shaft is identified and used in the development of a monitoring tool. The results are then used as a benchmark against which to test the performance of artificial neural networks as a tool for reactor diagnostics. Several neural networks are examined in this study, including Restricted Coulomb Energy (RCE), Cascade Correlation, and Backpropagation paradigms of artificial neural networks. RCE is selected due to its unique design and speed, Backpropagation is selected because it is widely used and well accepted in the neural network research community, and Cascade correlation is selected because it overcomes some of the problems associated with the Backpropagation paradigm. Similar study is performed using the Adaptive Resonance Theory (ART) family of neural network paradigms. The results of this study indicate that artificial neural networks are simpler techniques for pattern recognition than noise analysis techniques such as the one introduced here. Neural networks do not require prior fault related parameter identification; they generate their own rules by learning from being shown examples. On the other hand, noise analysis and regression modeling can provide very sensitive techniques for monitoring of a detected problem in a component.
Double-stage picosecond Kerr gate for ballistic time-gated optical imaging in turbid media.

We demonstrate that use of a picosecond double-stage Kerr gate system results in a 3-orders-of-magnitude improvement in signal-to-noise ratio and a threefold improvement in shutter speed compared with those of a single-stage Kerr gate.
Control model for a continuous face sheet, MEMS based deformable membrane mirror

Small Micro-Electro-Mechanical Systems (MEMS) deformable mirror (DM) technology is of great interest to the adaptive optics (AO) community. These MEMS-DM's are being considered for many conventional AO applications since they posses some advantages over conventional DM's. The MEMS-DM technology is driven by the expectation of achieving improved performance with lower costs, low electrical power, high number of actuators, high production rates, and large reductions in structural mass and volume. In addition to the imaging community, the directed energy community is also interested in taking advantage of the characteristics which MEMS-DM's offer. Unlike imaging, the optical fill-factor of a high-energy laser DM, has to be essentially 100 percent! Many modern MEMS-DM designs consist of small, lightweight, segmented mirrors that can be precisely controlled. For high-energy laser applications, the MEMS DM's should have a continuous reflective face-sheet with no gaps. This continuous reflective face-sheet must include high-energy laser coatings, which render the face sheet very stiff. This is a new challenge for MEMS-DM's, which has not previously been addressed. The Air Force Research Laboratory has proposed to meet this challenge with several continuous face-sheet high-energy laser MEMS-DM's designs. This paper will give a generic description of a MEMS-DM computer model. The research goal is to develop a MEMS-DM model for closed loop control of a high-energy laser, MEMS-DM adaptive optics application.
The lead oxide-catalyzed decomposition of nitroalkanes☆

Abstract Lead oxide (PbO) has been found to bring about the decomposition of gaseous primary and secondary nitroalkanes in the temperature range of 130 to 160°C in a period of a few minutes. The reaction occurs at the solid surface but the lead oxide is not changed except by reaction with carbon dioxide. For nitroethane, the most studied of the nitroalkanes investigated here, the main products are acetonitrile and nitrous oxide. Reaction is characterized by an induction period during which no reaction occurs and a reaction period, characterized by a pressure rise. A mechanism involving nitronic acid intermediates is proposed.
Superlattice k⋅p models for calculating electronic structure

A quantitative comparison is presented of two realistic superlattice k\ensuremath{\cdot}p electronic structure calculations. The first is an analytic approach based on an extended bulk Kane model; the second is an extended-basis treatment, developed by McGill and collaborators, based on bulk pseudopotential calculations. Both approaches are applied to HgTe/CdTe superlattices. Energies, wave functions, effective masses, and oscillator strengths are found to agree within 10%. The limited-basis approach based on the Kane model is seen to be adequate for superlattices whose bulk constituents have direct gaps in the conduction- and valence-band regions near the superlattice band gap.
Talc-thermoplastic compounds: particle orientation in flow and rheological properties

Abstract We describe an investigation of the orientation of talc particles in flow and the rheological properties of talc-thermoplastic compounds. The orientation of talc particles in samples removed from rheometers was determined using a wide angle X-ray diffraction technique. Talc particles, being disc-like in shape, orient with the disc normals perpendicular to the flow direction in the sandwich, cone-plate, parallel plate, capillary, and elongational rheometer. The level of orientation of particles is represented in terms of orientation factors. A broad range of experimental studies of the shear, elongational, and oscillatory flow behavior on thermoplastic melts with high loadings of talc particles is presented. The rheological measurements include the steady state shear viscosity, transient shear viscosity, elongational viscosity, complex viscosity, storage modulus, and loss modulus. Generally, the viscosity increases with increasing particle loading and with decreasing particle size. At low deformation rates, the stresses build up in an unbounded manner. There are stresses below which there is no flow indicating the existence of yield values. The implication of yield values in anisotropic particle compounds is considered. The compound as studied is considered a liquid crystalline particle array. The implication of the measurements to rheological modelling is considered.
A method for obtaining the 14C-isotope distribution in malate(C-2,3).

A method is described for the analysis of the isotope distribution in malate(C-2,3). In a single test-tube reaction, the inner carbon atoms of malate are enzymically converted to acetate and are stereospecifically incorporated into citrate as acetyl-CoA. A rapid method for obtaining the intramolecular isotope distribution in citrate(C-1,2) permits calculation of the isotope distribution and specific activity of the original malate carbon atoms. The error is less than 3%. This method is relevant to the recently reported problem of anomalous isotope distributions in the organic acids of C3 plants following short-term photosynthesis in 14CO2.
Variations in Magnetic Intensity and Climatic Changes

CORRELATION between the variations of the Earth's magnetic field, fluctuations in atmospheric radiocarbon activity, and climatic changes during the past 7,000 yr has been discussed extensively in the past1–7. In addition, Harrison8 has suggested that reversals of the Earth's magnetic field could cause climatic changes. With an associate we have recently9 been able tentatively to conclude on the basis of studies of deep-sea sediment cores that in the past 470,000 yr the magnetism of the Earth has modulated climate. We have now extended the correlation between variations of the magnetic intensity and evidence of climatic change from deep-sea sediment cores back to 1.2 m.y.
Two hybrid differential evolution algorithms for engineering design optimization

This paper presents two hybrid differential evolution algorithms for optimizing engineering design problems. One hybrid algorithm enhances a basic differential evolution algorithm with a local search operator, i.e., random walk with direction exploitation, to strengthen the exploitation ability, while the other adding a second metaheuristic, i.e., harmony search, to cooperate with the differential evolution algorithm so as to produce the desirable synergetic effect. For comparison, the differential evolution algorithm that the two hybrids are based on is also implemented. All algorithms incorporate a generalized method to handle discrete variables and Deb's parameterless penalty method for handling constraints. Fourteen engineering design problems selected from different engineering fields are used for testing. The test results show that: (i) both hybrid algorithms overall outperform the differential evolution algorithms; (ii) among the two hybrid algorithms, the cooperative hybrid overall outperforms the other hybrid with local search; and (iii) the performance of proposed hybrid algorithms can be further improved with some effort of tuning the relevant parameters.
Product differentiation, external economies and MNE location choices: M&As in Global Cities

Recent research has addressed the heterogeneity among MNEs in terms of their tendency to agglomerate. In this paper, we extend the scope of the firm-specific attributes considered to affect this agglomeration tendency by examining product differentiation. We find significant association between product differentiation and the preferences of firms for proximity to other firms in their industry. These findings imply that the value of agglomeration varies for firms pursuing different product differentiation strategies. We propose a conceptualization of product and location differentiations as two related dimensions of MNEs’ strategy.
In vitro testing for allergy diagnosis

The measurement of specific IgE antibodies has progressed so that highly reproducible, accurate, and quality-controlled tests are available [62]. These tests can certainly assist all physicians in evaluating allergic problems and are likely to be used widely in the future. Continued research is allowing the refinement of these tests as well as increasing the understanding of allergens and allergic disease. In vitro testing techniques are major assets to allergy care. Either in vitro or skin methods are appropriate modalities for the diagnosis of allergic rhinitis [45]. When the merits of the allergy skin test and in vitro tests for diagnosis of specific allergens are compared, the following statements are considered to be correct at this time: 1. Optimally performed skin tests and in vitro tests detect IgE E antibody accurately and reproducibly. 2. Results of both tests correlate equally well with allergic signs and symptoms produced by exposure to the specifically tested allergen. 3. Both tests can be used as grounds for instituting avoidance therapy and immunotherapy efficiently and economically.
A practical approach to incidental findings in neuroimaging research

Objective: We describe the systematic approach to incidental findings (IFs) used at the Mind Research Network (MRN) where all MRI scans receive neuroradiologist interpretation and participants are provided results. Methods: From 2004 to 2011, 8,545 MRI scans were acquired by 45 researchers. As mandated by MRN′s external institutional review board, all structural sequences were evaluated by a clinical neuroradiologist who generated a report that included recommendations for referral if indicated. Investigators received a copy of their participants9 reports, which were also mailed to participants unless they specifically declined. To better understand the impact of the radiology review process, a financial analysis was completed in addition to a follow-up phone survey to characterize participant perceptions regarding receiving their MRI scan results. Results: The radiologist identified IFs in 34% of the 4,447 participants. Of those with IFs (n = 1,518), the radiologist recommended urgent or immediate referral for 2.5% and routine referral for 17%. For 80.5%, no referral was recommended. Estimated annual cost for this approach including support for the neuroradiologist, medical director, and ancillary staff is approximately $60,000 or $24/scan. The results of the retrospective phone survey showed that 92% of participants appreciated receiving their MRI report, and the majority stated it increased their likelihood of volunteering for future studies. Conclusions: Addressing IFs in a cost-effective and consistent manner is possible by adopting a policy that provides neuroradiology interpretation and offers participant assistance with clinical follow-up when necessary. Our experience suggests that an ethical, institution-wide approach to IFs can be implemented with minimal investigator burden.
Restless Giant: The Life and Times of Jean Aberbach & Hill and Range Songs

Bar Biszick-Lockwood has written an extensively detailed and illuminating biography of Jean Aberbach, an Austrian-born, twentieth-century, music publishing magnate. Through her engagement with Aber...
Characterization of the 16S rRNA gene V2 region and the rrn operons of Gardnerella vaginalis

Ribosomal RNA (rRNA) gene polymorphism was apparent when Gardnerella vaginalis DNA restriction profiles were hybridized with nonradioactively labeled total rRNA isolated from this bacterium. In contrast, use of a polymerase chain reaction (PCR)-based 16S rRNA gene V2 region resulted in a 118-bp V2-PCR amplicon that was specific and common in all 30 tested G. vaginalis isolates. In addition to providing a G. vaginalis-specific fingerprint, when the V2-PCR amplicon along with total rRNA were utilized as probes, a partial rRNA gene restriction map could be constructed. G. vaginalis contains two rrn operons with an EcoRI fragment of 1.6 kb common to both.