cssi/SciSciGPT-SciSciNet huggingface dataset:
Use of drilling performance to improve rock-breakage efficiencies: A part of mine-to-mill optimization studies in a hard-rock mine

Abstract In a hard-rock mine, blasting is an important rock-breakage process that impacts energy consumption both in downstream comminution processes and mine productivity. Optimizing the blast fragmentation to improve rock-breakage efficiencies during crushing and grinding is key to mine-to-mill (MTM) optimization. This study explores the use of monitoring while drilling (MWD) data to achieve this goal. Representative penetration rates (PRs) were extracted from blastholes to estimate intact rock properties and predict the breakage efficiencies that directly affect comminution energy consumption. Two intact rock properties, tensile strength (TS) and Bond work index (BWI), were correlated with the PR data to predict these efficiencies in crushing and grinding, respectively. Because of the complexity of the raw MWD data and effects of various disturbances, the MWD data was preprocessed and normalized to achieve a representative PR value at each blasthole. This preprocessing entailed defining valid PR ranges from the MWD data that could eliminate the noise related to discontinuity features in the rock mass structure as well as errors in operator behaviors. The PR data was also normalized using the adjusted penetration rate (APR) to minimize the effects of mechanical factors such as drill feed force, torque, and rotational speed. To correlate the representative APR value with intact rock properties, TS and BWI, various laboratory experiments were conducted: drilling tests using a high-precision coring machine, Brazilian disc tests, and Bond grindability tests. Based on the results of these experiments, models were developed to predict rock-breakage efficiencies during crushing and grinding based on APR. The result of this study can be used to obtain blast energy designs that consider comminution energy consumption and efficiency in the downstream rock-breakage processes.
Face- and Cell-Averaged Nodal-Gradient Approach to Cell-Centered Finite-Volume Method on Mixed Grids

In this paper, the averaged nodal-gradient approach previously developed for triangular grids is extended to mixed triangular-quadrilateral grids. It is shown that the face- averaged approach leads to deteriorated iterative convergence on quadrilateral grids. To develop a convergent solver, we consider cell-averaging instead of face-averaging for quadri- lateral cells. We show that the cell-averaged approach leads to a convergent solver and can be efficiently combined with the face-averaged approach on mixed grids. The method is demonstrated for various inviscid and viscous problems from low to high Mach numbers on two-dimensional mixed grids.
PCC: A Leader of Change

From its beginnings, the Program for Cooperative Cataloging (PCC) has been an international leader of change in bibliographic and authority control and maintenance, and metadata creation and distri...
CHAPTER 6 – CRYPTOGRAPHIC TRANSFORMATIONS

Whether it is geographically centralized or distributed, a computer system may be viewed as a network of terminals, storage devices, and processing units. Thus, we have communications among the terminals, devices, and units. Cryptographic transformations are techniques for encoding data to hide their content in the course of communications in the network.
Ecology and Epidemiology of Wheat Curl Mite and Mite-Transmissible Viruses in Colorado and Insights into the Wheat Virome

The wheat curl mite (WCM)-transmissible wheat streak disease complex is the most serious disease of wheat in the U.S. Great Plains. In the current study, we determined the genetic variability in WCM and mite-transmitted viruses in Colorado and identified sources of resistance in Colorado wheat germplasm to wheat streak disease complex. We identified two distinct genotypes of WCM, Type 1 and Type 2 based on the ribosomal ITS1 region. Both genotypes were found to co-exist throughout the wheat producing regions of Colorado. Analysis of the whole genome and partial coat protein sequences revealed rich diversity of wheat streak mosaic virus (WSMV) and High Plains wheat mosaic virus (HPWMoV) isolates collected from Colorado, whereas triticum mosaic virus (TriMV) showed low sequence variability. Analysis of WSMV isolates revealed two novel isolates and one that was 100% similar to a new variant of WSMV from Kansas. Interestingly, between 2-4 genotypes of all 8 RNA segments of HPWMoV were identified, which suggests new variants of emaraviruses and co-occurrence of multiple strains within host populations. Several novel viruses including mycoviruses were identified for the first time in Colorado. We found variation in WSMV resistance among wheat varieties; however a variety that harbored dual resistance to mite and WSMV had lower virus titer compared to varieties that contained single resistance gene. This suggests that pyramiding genes will ensure improved and durable resistance. Future research may be aimed at elucidating the dynamics, diversity, and distribution of the new WSMV and HPWMoV isolates and their responses to wheat genotypes.
Dynamic bayesian networks based abnormal event classifier for nuclear power plants in case of cyber security threats

Abstract With increased adoption of digital systems for instrumentation and control, nuclear power plants have become more vulnerable to cyber-attacks. Such attacks can have very serious implications on a plant's operation, especially if they masquerade as safety events. Thus, it is important that research be focused towards distinguishing cyber-attacks from fault induced safety events for a correct response in a timely manner. In this paper, an event classifier is presented to classify abnormal events in nuclear power plants as either fault induced safety events or cyber-attacks. The process of inferring the hidden (unobservable) state of a system (normal or faulty) through observable physical sensor measurements has been a long-standing industry practice. There has been a recent surge of literature discussing the use of network traffic data for the detection of cyber-attacks on industrial control systems. In the classifier we present, both physical and network behaviors of a nuclear power plant during abnormal events (safety events or cyber-attacks) are used to infer the probabilities of the states of the plant. The nature of the abnormal event in question is then determined based on these probabilities. The Dynamic Bayesian Networks (DBNs) methodology is used for this purpose since it is an appropriate framework for inferring hidden states of a system from observed variables through probabilistic reasoning. In this paper we introduce a DBN based abnormal event classifier and an architecture to implement this classifier as part of a monitoring system. An experimental environment is setup with a two-tank system in conjunction with a nuclear power plant simulator and a programmable logic controller. A set of 27 cyber-attacks and 14 safety events were systematically designed for the experiment. A set of 6 cyber-attacks and 2 safety events were used to manually finetune the Conditional Probability Tables (CPTs) of the 2-timeslice dynamic Bayesian network (2T-DBN). Out of the remaining 33 events, the nature of the abnormal event was successfully identified in all the 33 cases and the location of the cyber-attack or fault was successfully determined in 32 cases. The case-study demonstrates the applicability of the methodology developed. Further research should examine the practicality of implementing the proposed monitoring system on a real-world system and issues associated with cost optimization.
Investigating the effects of absolute humidity and human encounters on transmission of COVID-19 in the United States

Abstract Background Mounting evidence suggests that the primary mode of transmission of SARS-CoV-2 is aerosolized transmission from close contact with infected individuals. Even though transmission is a direct result of human encounters, environmental conditions, such as lower humidity, may enhance aerosolized transmission risks similar to other respiratory viruses such as influenza. Methods We utilized dynamic time warping to cluster all 3,137 counties in the United States based on temporal data on absolute humidity from March 10 to September 29, 2020. We then used a multivariate generalized additive model (GAM) combining data on human mobility derived from mobile phone data with humidity data to identify the potential effect of absolute humidity and mobility on new daily cases of COVID-19 while considering the temporal differences between seasons. Results The clustering analysis found ten groups of counties with similar humidity levels. We found a significant negative effect between increasing humidity and new cases of COVID-19 in most regions, particularly in the period from March to July. The effect was greater in regions with generally lower humidity in the Western, Midwest, and Northeast regions of the US. In the two regions with the largest effect, a 1 g/m3 increase of absolute humidity resulted in a 0.21 and 0.15 decrease in cases. The effect of mobility on cases was positive and significant across all regions in the July-Sept time period, though the relationship in some regions was more mixed in the March to June period. Conclusions We found that increasing humidity played an important role in falling cases in the spring, while increasing mobility in the summer contributed more significantly to increases in the summer. Our findings suggest that, similar to other respiratory viruses, the decreasing humidity in the winter is likely to lead to an increase in COVID-19 cases. Furthermore, the fact that mobility data were positively correlated suggests that efforts to counteract the rise in cases due to falling humidity can be effective in limiting the burden of the pandemic.
The value of simplicity: externally validating the Baylor cranial gunshot wound prognosis score.

Objective Gunshot wounds to the head (GSWH) are devastating injuries with a grim prognosis. Several prognostic scores have been created to estimate mortality and functional outcome, including the so-called Baylor score, an uncomplicated scoring method based on bullet trajectory, patient age, and neurological status on admission. This study aimed to validate the Baylor score within a temporally, institutionally, and geographically distinct patient population. Methods Data were obtained from the trauma registry at a level I trauma center in the southeastern US. Patients with a GSWH in which dural penetration occurred were identified from data collected between January 1, 2009, and June 30, 2019. Patient demographics, medical history, bullet trajectory, intent of GSWH (e.g., suicide), admission vital signs, Glasgow Coma Scale score, pupillary response, laboratory studies, and imaging reports were collected. The Baylor score was calculated directly by using its clinical components. The ability of the Baylor score to predict mortality and good functional outcome (Glasgow Outcome Scale score 4 or 5) was assessed using the receiver operating characteristic curve and the area under the curve (AUC) as a measure of performance. Results A total of 297 patients met inclusion criteria (mean age 38.0 [SD 15.7] years, 73.4% White, 85.2% male). A total of 205 (69.0%) patients died, whereas 69 (23.2%) patients had good functional outcome. Overall, the Baylor score showed excellent discrimination of mortality (AUC﻿﻿ = 0.88) and good functional outcome (AUC = 0.90). Baylor scores of 3-5 underestimated mortality. Baylor scores of 0, 1, and 2 underestimated good functional outcome. Conclusions The Baylor score is an accurate and easy-to-use prognostic scoring tool that demonstrated relatively stable performance in a distinct cohort between 2009 and 2019. In the current era of trauma management, providers may continue to use the score at the point of admission to guide family counseling and to direct investment of healthcare resources.
A retrospective evaluation of the indications, complications, and outcomes associated with epicardial pacemakers in 20 cats from a single institution.

Abstract Introduction The objective of this retrospective study was to describe the indications, complications, and long-term outcomes in a group of cats that received an epicardial pacing (EP) system. Animals Twenty client-owned cats. Materials and methods Medical records were reviewed for signalment, presenting complaint, primary electrocardiogram (ECG) diagnosis, presence of structural heart disease, presence of congestive heart failure (CHF), presence of major or minor complications, and survival time. Results The majority of cats were presented for syncope (n = 11), and the most common ECG diagnosis was advanced second-degree atrioventricular block (n = 9). Fifteen cats (15/20, 75%) had one or more major or minor complications. One cat died in the perioperative period as a result of a major complication. None of the variables evaluated were associated with a statistically significant increase in the occurrence of major or minor complications. The most common major complication was loss of ventricular capture (seven instances in six cats), which was successfully treated in all cases by increasing pacemaker output or replacing both the lead and the pulse generator. The most common minor complications were arrhythmias (n = 7) and sensing issues (n = 8). The overall median survival time (MST) was 948 days. No statistical difference in survival time was identified between cats that experienced a major complication and those that did not. Conclusions Although complications were common in this feline population after EP, major and minor complications were successfully treated.
Chemical Characterization of Films

Biofilms represent a complex assembly of different groups of attached microbes with their excretory products. Sensitive measures of the biomass, community structure, nutritional status, and metabolic activities, as well as the chemical characterization of their extracellular polymers, have given insight into the ecology of this system. Exposure of surfaces to flowing waters produces a succession of microbes whose community structure and metabolic activity is affected by the chemistry, biodegradability, and microtopography of the surface, as well as the shear forces and nutrient content of the flowing waters. The grazing of the biofilm by predators or the mechanical or chemical disruption of the biofilm greatly affect the metabolic activity and the potential for secondary reaccumulation and the secretion of extracellular polymers. The extracellular polymers formed by the biofilm microbes are particularly important as they greatly increase the resistance of the microbes to biocides and the efficiency of heat transfer. The metabolic activity of thin biofilm can create microanaerobic sites that facilitate the growth of fermenters and hydrogen utilizers whose acidic fermentation products can greatly facilitate corrosion. The microanalytical methods currently available require the destruction of the biofilm in its assay. With progress in instrumentation the destructive sampling can be supplanted by nondestructive continuous monitoring, possibly utilizing a Fourier transforming infrared system which may provide insights into the chemical basis of adhesion and interactions between the components of the biofilm microbial assembly.
Cortical Effects of Early Visual Experience

Behavioral and physiological evidence indicates that the visual system responds preferentially to horizontal and vertical patterns (see HELD’s presentation at this Symposium). To determine whether this bias is a consequence of an animal’s early visual experience, we have compared the effects of early selective exposure to diagonal lines with the effects of early exposure to horizontal and vertical lines (1).
Analysis of Heterogeneous Nucleation in Ductile Iron

A combination of an automated SEM/EDX analysis, a special 2D-3D converter of nodule size distribution, and adaptive thermal analysis were used for the study of heterogeneous nucleation in ductile iron. The special quenching technique was applied to increase probability to reveal non-metallic heterogeneous nuclei in small graphite nodules. Ternary diagrams were developed to compare statistics of oxide and sulfide compositions in graphite nodules and metal matrix. Thermodynamics of heterogeneous nucleation of graphite phase in Mg-treated cast iron is discussed based on the novel experimental data.
Active vibro-acoustic control of a flexible beam using distributed control

In this paper distributed control is applied to control the noise radiation of a flexible structure. The purpose is to investigate the effectiveness and ease of implementation versus current methods. As an illustrative example a simple supported beam is chosen. It is shown that the distributed controller is able to control the noise by penalizing the velocity states and it is shown that this results in less noise radiation, both in the near and far field. The distributed controller outperforms a local velocity feedback controller. Also, in comparison to local velocity feedback, it has the advantage that stability is guaranteed when the actuators are not assumed to be point actuators.
Basic mechanisms of itch.

Chronic itch represents a burdensome clinical problem that can originate from a variety of etiologies. Pruriceptive itch originates following the activation of peripheral sensory nerve endings following damage or exposure to inflammatory mediators and ascends to the brain through the spinal thalamic tract. Much insight has been gained into the understanding of the mechanisms underlying pruriceptive itch through studies using humans and experimental animals. More than one sensory nerve subtype is thought to subserve pruriceptive itch which includes both unmyelinated C-fibers and thinly myelinated Aδ nerve fibers. There are a myriad of mediators capable of stimulating these afferent nerves leading to itch, including biogenic amines, proteases, cytokines, and peptides. Some of these mediators can also evoke sensations of pain and the sensory processing underlying both sensations overlaps in complex ways. Studies have demonstrated that both peripheral and central sensitization to pruritogenic stimuli occur during chronic itch.
Renal afferent input to the ventrolateral medulla of the cat

Experiments were performed to determine if information from the kidneys projects to the rostral ventrolateral medulla. Extracellular action potentials were recorded from 148 cells within the rostral ventrolateral medulla of alpha-chloralose-anesthetized cats. Cells within the rostral ventrolateral medulla were tested for responses to electrical stimulation of both left and right renal nerves. Electrical stimulation of renal nerves excited 144 cells (97.3%) and inhibited 4. The majority of cells received either bilateral or contralateral renal nerve input. Cells with bilateral renal nerve input responded to contralateral renal nerve stimulation with a significantly greater number of impulses compared with ipsilateral renal nerve stimulation (P less than 0.05). All cells but one responding to renal nerve stimulation had convergent somatic input. Comparisons between thresholds for cell responses and activation thresholds for the A and C volleys of the compound action potential recorded in the least splanchnic nerve revealed that 44 cells required activation of A delta-fibers, and 12 cells required activation of both A delta- and C-fibers. A conditioning stimulus applied to renal nerves on one side significantly decreased the response elicited by a test stimulus applied to the renal nerves on the opposite side for at least 300 ms (P less than 0.05). The demonstration that an afferent connection exists between the kidneys and the ventrolateral medulla suggests that the rostral ventrolateral medulla may play a role in mediating supraspinal reflexes of renal origin.
Improved Heuristics for Minimum-Flip Supertree Construction

The utility of the matrix representation with flipping (MRF) supertree method has been limited by the speed of its heuristic algorithms. We describe a new heuristic algorithm for MRF supertree construction that improves upon the speed of the previous heuristic by a factor of n (the number of taxa in the supertree). This new heuristic makes MRF tractable for large-scale supertree analyses and allows the first comparisons of MRF with other supertree methods using large empirical data sets. Analyses of three published supertree data sets with between 267 to 571 taxa indicate that MRF supertrees are equally or more similar to the input trees on average than matrix representation with parsimony (MRP) and modified min-cut supertrees. The results also show that large differences may exist between MRF and MRP supertrees and demonstrate that the MRF supertree method is a practical and potentially more accurate alternative to the nearly ubiquitous MRP supertree method.
A Collage of Ethnographies

Ethnography Unbound: Power and Resistance in the Modern Metropolis, by Michael Burawoy, Alice Burton, Ann Arnett Ferguson, Kathryn J. Fox, Joshua Gamson, Nadine Gartrell, Leslie Hurst, Charles Kurzman, Leslie Salzinger, Josepha Shiffman, and Shiori Ui.
Detection of 17.5‐day period meridional current oscillations in the equatorial western Pacific Ocean during 1985

The first long-term, near equatorial, near surface moored current measurements recorded in the Pacific Ocean west of 160 deg W were made at 0 deg, 150 deg E during August 2, 1985 to February 1, 1986. These data revealed 17.5-day period oscillations of the meridional current. Prior to these measurements, these waves had only been observed eastward of about 165 deg W, which also was the westernmost extent of their appearance in ocean general circulation model simulations. The 17.5-day period waves also occurred in simultaneous current measurements at 140 deg W, where the wave amplitude was 3 times greater. At both sites the 17.5-day period wave amplitude was more than 50 percent of the record-length standard deviations of the meridional current component. A wider spectral bandwidth and a smaller tendency towards rectilinear motion occurred at 150 E than at 140 W.
Dual-mode plasmonic nanorod type antenna based on the concept of a trapped dipole

In this paper we theoretically investigate the feasibility of creating a dual-mode plasmonic nanorod antenna. The proposed design methodology relies on adapting to optical wavelengths the principles of operation of trapped dipole antennas, which have been widely used in the low MHz frequency range. This type of antenna typically employs parallel LC circuits, also referred to as "traps", which are connected along the two arms of the dipole. By judiciously choosing the resonant frequency of these traps, as well as their position along the arms of the dipole, it is feasible to excite the λ/2 resonance of both the original dipole as well as the shorter section defined by the length of wire between the two traps. This effectively enables the dipole antenna to have a dual-mode of operation. Our analysis reveals that the implementation of this concept at the nanoscale requires that two cylindrical pockets (i.e. loading volumes) be introduced along the length of the nanoantenna, inside which plasmonic core-shell particles are embedded. By properly selecting the geometry and constitution of the core-shell particle as well as the constitution of the host material of the two loading volumes and their position along the nanorod, the equivalent effect of a resonant parallel LC circuit can be realized. This effectively enables a dual-mode operation of the nanorod antenna. The proposed methodology introduces a compact approach for the realization of dual-mode optical sensors while at the same time it clearly illustrates the inherent tuning capabilities that core-shell particles can offer in a practical framework.
A perspective on the role of catheter ablation in the management of tachyarrhythmias.

The first clinical application of a catheter ablation technique was to create complete atrioventricular (AV) block by the transcatheter delivery of a direct-current shock to the AV junction in patients with supraventricular tachycardia refractory to pharmacologic therapy.^'^ This was followed by attempts at catheter ablation of ventricular tachycardia (VT) foci, accessory pathways, and atrial tachycardia foci. The purpose of this article is to provide a perspective on the current role of these catheter ablation techniques in the management of patients with tachyarrhythmias.
A gene affecting the repression of invertase and trehalase in Neurospora.

Growth of Neurospora on media containing mannose results in low activities of invertase and trehalase, whereas very high levels of these enzymes are attained during growth in galactose media. A mutant has been isolated which, under suitable conditions of culture, produces much larger amounts of these two enzymes than does the parental strain. Evidence is presented that the levels of enzymes are affected by a single gene alteration.
Cloud fragmentation and stellar masses

Longueurs critiques et masses necessaires a la fragmentation. Effets de rotation et champs magnetiques. Comparaison avec des simulations. Masses critiques dans les nuages interstellaires. Comparaisons avec les observations. Limites d'une fragmentation continue
Dichromated Gelatin Holograms And Their Applications

Dichromated gelatin holograms, properly recorded and processed, have so little scattering and absorption that they are nearly indistinguishable from clear glass plates. Dichromated gelatin is the best material today for the fabrication of holographic optical elements and certain reflection type image holograms because of its low scattering, large refractive index modulation capacity, moderate exposure level, high resolution capacity, good environmental stability with a cover plate, and other unique properties such as reprocessibility and relatively easy hologram thickness control. We first review the mechanism of hologram formation in dichromated gelatin and holographic characteristics and then discuss several promising applications of dichromated gelatin holograms such as holographic optical elements (or holographic optics components) and information storage and display.
Structure-relationships in electrocatalysis: oxygen reduction and hydrogen oxidation reactions on Pt(111) and Pt(100) in solutions containing chloride ions

Abstract Kinetics of the oxygen reduction reaction (orr) and the hydrogen evolution–oxidation reactions (her/hor) were studied on the Pt(111) and Pt(100) surfaces in 0.05 M H2SO4 containing Cl−. The orr is strongly inhibited on the (100) surface modified by adsorbed Cl− (Clad), and it occurs as a 3.5e− reduction via solution phase peroxide formation. In the hydrogen adsorption (Hupd) potential region, the orr is even more inhibited, and corresponds only to a 2 e− reduction at the negative potential limit where the electrode is covered by one monolayer of Hupd and some (unknown) amount of Clad. On the Pt(111)Clad surface, the orr is inhibited relatively little (in addition to that caused by strong bisulfate anion adsorption on this surface), and the reaction pathway is the same as in Cl− free solution. The kinetics of the hor on Pt(111) are the same in pure solution and in a solution containing Cl−, since Clad does not affect platinum sites required for the breaking of the HH bond. A relatively large inhibition of the hor is observed on the (100) surface, implying that strongly adsorbed Clad is present on the surface even near 0 V.
Chemicals and children's environment: what we don't know about risks.

Abstract Although we know that certain types of childhood cancers are increasing, we do not know why. With few exceptions, we know little about the role of environmental carcinogens in childhood cancer. Generally, we have adequate information to screen chemicals for potential hazard for only certain categories of chemicals--drugs, food additives, and pesticides. The U.S. Environmental Protection Agency (U.S. EPA) is implementing the 1996 Food Quality Protection Act, which provides added protections against pesticide risks, especially for children. But the situation is quite different for many industrial chemicals. We lack even basic toxicity data for a majority of the U.S. EPA's list of approximately 3000 nonpolymeric high-production-volume industrial chemicals being produced in the United States each year that are found in consumer products and the workplace. We know even less about the remaining 70,000 chemicals on the U.S. EPA inventory. The U.S. EPA has initiatives underway to address the risks posed by some of these commercial chemicals, including efforts to reduce risks posed by indoor air pollutants and household products. These initiatives specifically address children's risks. We are supporting toxicity screening of high-volume industrial chemicals on a cooperative international basis through the Organisation for Economic Co-operation and Development. Until more information is available, it is difficult to assess the possible role of these chemicals in childhood cancer and to take steps to reduce exposure to children.
Investigating the use of an on-chip sensor to monitor NBTI effect in SRAM

Today, the increasing need to store more and more information has resulted in the fact that Static Random Access Memories (SRAMs) occupy the greatest part of a System-on-Chip (SoC). Therefore, SRAM's robustness is considered crucial to guarantee the reliability of such SoCs over lifetime. In this context, one of the most important phenomena degrading nano-scale SRAMs reliability is related to Negative-Bias Temperature Instability (NBTI). This paper proposes a new approach based on an On-Chip Aging Sensor (OCAS) to detect SRAM aging during system lifetime. The sensor is able to detect any specific aging state of a cell in the SRAM array. The strategy is based on the connection of an OCAS per SRAM column, which periodically performs off-line testing by monitoring write operations into the SRAM cells to detect aging. The approach is application-transparent since it is does not change the SRAM contents after testing. To prevent OCAS from aging by one side and from dissipating static power by the other side, OCAS circuitry is powered-off during idle periods. SPICE simulations in a 65nm CMOS technology demonstrate the high sensor sensitivity to detect early aging states and so, guarantying high memory reliability. Furthermore, area overhead due to sensor insertion is almost negligible.
Development of social spacing in normal and mentally retarded children

Distances between closest playmates were measured during free play in mentally retarded and normal grade school children. Unobtrusive observation techniques minimized interference and a spacious playground environment was chosen to avoid effects of confining walls on spatial behavior. Younger children (grades 1–3) kept closer distances than older children (grades 4–6), independent of clinical history or sex (p<.0001). Parallels are drawn with findings of previous observational studies in adults and non-human primates; two hypotheses, based on cognitive development and social disturbance, are proposed to explain the findings.
Electrochemical reduction of copper(II) salen at carbon cathodes in dimethylformamide

Abstract In dimethylformamide containing tetramethylammonium tetrafluoroborate, copper(II) salen undergoes a three-step reduction at a glassy carbon cathode; the first voltammetric wave is attributed to reduction of copper(II) to copper(I), the second is due to reduction of copper(I) to copper metal, and the third voltammetric wave results from reduction of the salen-dianion. In the presence of adventitious water which coordinates loosely to square-planar copper(II) salen and to distorted tetrahedral copper(I) salen, the first voltammetric wave exhibits only semi-reversible behavior, which differs from that reported for other metal–salen complexes. However, removing the water causes reversibility to be achieved. Upon addition of acetic acid, a new complex is formed which exhibits an irreversible one-electron reduction; a mechanism for the formation and electrochemical behavior of this species has been formulated.
Propagation of a Stationary Shock Layer in the Presence of a Boundary

We are interested in the large-time behavior of a stationary shock layer in the presence of a boundary effect. It is shown that the stationary shock propagates away from the boundary with speed inversely proportional to the time $t$ . Consequently, the location of the wave front is of order $\log \thinspace (1+t)$ . We show therefore that the zero-viscosity and time-asymptotic limits do not commute. Our analysis involves detailed point-wise estimates, which allow us to trace the shock.
Evaluation of Root and Canal Morphology of Maxillary Permanent First Molars in a North American Population by Cone-beam Computed Tomography

Abstract Introduction The purpose of this study was to evaluate the number of roots and canal morphology of maxillary permanent first molars in a North American population. Methods Three hundred seventeen cases with bilateral maxillary first molars were included. All images from cone-beam computed tomography were carefully reviewed by 2 endodontists. Frequency of number of roots, presence of an additional mesiobuccal canal (MB2), and Vertucci canal type for each root were tabulated. Age, gender, and ethnicity differences were calculated with the χ 2 test. The intra-rater reliability was assessed by using the Cohen kappa statistic. Results The fused root rate was 0.9%. The occurrence of 3-rooted maxillary first molars differed between left and right sides ( P = .03). MB2 occurrence only showed statistically significant differences among age groups ( P = .005). In the mesiobuccal roots, the most common Vertucci classifications of canal types were type IV (2-2, 41.9%), type I (1, 28.3%), and type II (2-1, 26.3%). There was a statistically significant difference in Vertucci classification of canal type among 5 ethnic groups (African American, Asian, Hispanic, Other, and Non-Hispanic white, P Conclusions Cone-beam computed tomography facilitates the identification of root and canal configuration. The information gained about the tooth anatomy and canal morphology before treatment could potentially facilitate root canal therapy.
Coevolution of adaptive technology, maladaptive culture and population size in a producer–scrounger game

Technology (i.e. tools, methods of cultivation and domestication, systems of construction and appropriation, machines) has increased the vital rates of humans, and is one of the defining features of the transition from Malthusian ecological stagnation to a potentially perpetual rising population growth. Maladaptations, on the other hand, encompass behaviours, customs and practices that decrease the vital rates of individuals. Technology and maladaptations are part of the total stock of culture carried by the individuals in a population. Here, we develop a quantitative model for the coevolution of cumulative adaptive technology and maladaptive culture in a 'producer-scrounger' game, which can also usefully be interpreted as an 'individual-social' learner interaction. Producers (individual learners) are assumed to invent new adaptations and maladaptations by trial-and-error learning, insight or deduction, and they pay the cost of innovation. Scroungers (social learners) are assumed to copy or imitate (cultural transmission) both the adaptations and maladaptations generated by producers. We show that the coevolutionary dynamics of producers and scroungers in the presence of cultural transmission can have a variety of effects on population carrying capacity. From stable polymorphism, where scroungers bring an advantage to the population (increase in carrying capacity), to periodic cycling, where scroungers decrease carrying capacity, we find that selection-driven cultural innovation and transmission may send a population on the path of indefinite growth or to extinction.
Dissolution mechanisms for U02 and spent fuel

Abstract The probable dissolution mechanisms for UO 2 and spent fuel were studied based on accelerating oxidation and dissolutions in autoclave and electrochemical experiments. The dissolution of UO 2 is primarily due to oxidation of U +4 (solid) to U +6 (liquid). The U +6 (liquid) is initially in dissolved uranyl ions, UO 2 +2 , but subsequent hydrolysis reactions lead to the formation of solid uranyl hydrates (or related complex compounds) that deposit onto the surfaces of UO 2 and container walls as thin or thick coatings, depending on the temperature, pH, and time. Therefore, the dissolution rate of UO 2 cannot be simply determined from the uranium content of the solution. Moreover, the dissolution rate is not limited by the solubility of the uranyl ions. Electrochemical dissolution of spent fuel shows that the initial dissolution and leaching behavior is similar to that of UO,, surfaces.
Mechanical Behavior of MoSi2 Reinforced–Si3N4Matrix Composites

The mechanical behavior of MoSi2 reinforced–Si3N4 matrix composites was investigated as a function of MoSi2 phase content, MoSi2 phase size, and amount of MgO densification aid for the Si3N4 phase. Coarse-phase MoSi2-Si3N4 composites exhibited higher room-temperature fracture toughness than fine-phase composites, reaching values >8 MP·am1/2. Composite fracture toughness levels increased at elevated temperature. Fine-phase composites were stronger and more creep resistant than coarse phase composites. Room-temperature strengths >1000 MPa and impression creep rates of ∼10−8 s−1 at 1200°C were observed. Increased MgO levels generally were deleterious to MoSi2-Si3N4 mechanical properties. Internal stresses due to MoSi2 and Si3N4 thermal expansion coefficient mismatch appeared to contribute to fracture toughening in MoSi2-Si3N4 composites.
Enzyme-Linked Immunosorbent Assay (ELISA) and Blocking with Bovine Serum Albumin (BSA) - Not all BSAs are alike

The enzyme-linked immunosorbent assay (ELISA) is an extremely common and powerful laboratory technique for detecting proteins by antibodies. Researchers frequently use bovine serum albumin (BSA) as a blocking agent to prevent non-specific binding of antigens and antibodies to the microtiter well. While studying the interactions of the vaccinia virus complement control protein (VCP) with complement, we found non-specific binding of VCP to BSA and identify a BSA preparation that did not result in non-specific binding. This work draws attention to the fact that not all BSA preparations are alike. It also highlights the need to perform critical controls to ensure that ELISA reactants do not inappropriately bind to the blocking agent.
Constrictive Pericarditis and Pleuropulmonary Disease Linked to Ergot Dopamine Agonist Therapy (Cabergoline) for Parkinson's Disease

Cabergoline is one of several ergoline dopamine agonist medications used in the treatment of Parkinson's disease (PD). We diagnosed constrictive pericarditis (CP) in a patient with PD receiving cabergoline therapy (10 mg daily), who had symptoms and signs of congestive heart failure (CHF). In the absence of previous reported cases of this condition linked to ergoline drugs, cabergoline was not initially identified as the cause. Shortly thereafter, however, the patient developed of a severe pleuropulmonary inflammatory-fibrotic syndrome, a recognized complication of ergoline medications, thus suggesting a common pathogenesis due to cabergoline therapy. To our knowledge, this is the first case in the English literature, although we speculate that CP may be more common than reported among patients with PD who are treated with an ergoline drug (cabergoline, bromocriptine, pergolide, or lisuride). The diagnosis of CP is difficult and requires a high level of suspicion; symptoms may masquerade as CHF due to common mechanisms such as coronary artery disease. In patients with PD who are taking not only cabergoline but also one of the other ergoline drugs, CP should be suspected if symptoms of CHF develop.
Isolation and characterization of microsatellite DNA loci in the threatened flat-spired three-toothed land snail Triodopsis platysayoides

The hermaphroditic flat-spired three-tooth land snail (Triodopsis platysayoides) is endemic to a 21-km stretch of the Cheat River Gorge of northeastern West Virginia, USA. We document isolation and characterization of ten microsatellite DNA markers in this at-risk species. The markers displayed a moderate level of allelic diversity (averaging 7.1 alleles/locus) and heterozygosity (averaging 58.6 %). Allelic diversity at seven loci was sufficient to produce unique multilocus genotypes; no indication of selfing was detected in this cosexual species. Minimal deviations from Hardy–Weinberg equilibrium and no linkage disequilibrium were observed within subpopulations. All loci deviated from Hardy–Weinberg expectations when individuals from subpopulations were pooled. Microsatellite markers developed for T. platysayoides yielded sufficient genetic diversity to (1) distinguish all individuals sampled and the level of selfing; (2) be appropriate for addressing fine-scale population structuring; (3) provide novel demographic insights for the species; and (4) cross-amplify and detect allelic diversity in the congeneric T. juxtidens.
Real-time characterization of cytotoxicity using single-cell impedance monitoring

Cellular impedance sensors have attracted great attention as a powerful characterization tool for real-time, label-free detection of cytotoxic agents. However, impedance measurements with conventional cell-based sensors that host multiple cells on a single electrode neither provide optimal cell signal sensitivity nor are capable of recording individual cell responses. Here we use a single-cell based platform to monitor cellular impedance on planar microelectrodes to characterize cellular death. In this study, individual cells were selectively patterned on microelectrodes with each hosting one live cell through ligand-mediated natural cell adhesion. Changes in cellular morphology and cell–electrode adherence were monitored after the patterned cells were treated with varying concentrations of hydrogen peroxide, sodium arsenite, and disodium hydrogen arsenate, three potent toxicants related to neurotoxicity and oxidative stress. At low toxicant concentrations, impedance waveforms acquired from individual cells showed variable responses. A time- and concentration-dependent response was seen in the averaged single-cell impedance waveform for all three toxicants. The apoptosis and necrosis characterizations were performed to validate cell impedance results. Furthermore, time constants of apoptosis and necrosis in response to toxicant exposure were analytically established using an equivalent circuit model that characterized the mechanisms of cell death.
Erectness of posture as an indicator of dominance or success in humans

Darwin and others have perceived parallels between the erect bearing of proud, successful humans and the expansive demeanor of dominant animals. Various additional parallels between man and other primates in the characteristics of dominance hierarchies, the facial and postural expression of dominance, and its possible neural mediation are described. In the present study, success by human subjects in various situations was found to be reflected by erect posture. In a longitudinal study, boys who had been ranked by peers as “tough,” or dominant in agonistic encounters, in early grade school were observed to have erect posture in high school. Further, high school students who were judged by peers as successful by group standards tended to have erect posture. Finally, erectness of posture was related to performance on a college examination, with students' posture changing in erectness upon their receiving their grade. These results are consistent with the hypothesis that human competition for social success is based upon a biological capacity for dominance hierarchization.
Real-time face tracking

A real-time face tracker is presented in this paper. The system has achieved 15 frames/second tracking using a Pentium 200 PC with a Datacube MaxPCI image processing board and a Panasonic RGB color camera. It tracks human faces in the camera's field of view while people move freely. A stochastic model to characterize the skin color distribution of human skin is used to segment the face and other skin areas from the background. Median filtering is then used to clean up the background noise. Geometric constraints are applied to the segmented image to extract the face from the background. To reduce computation and achieve real-time tracking, 1D projections (horizontal and vertical) of the image are analyzed instead of the 2D image. Run-length- encoding and frequency domain analysis algorithms are used to separate faces from other skin-like blobs. The system is robust to illumination intensity variations and different skin colors. It can be applied to many human-computer interaction applications such as sound locating, lip- reading, gaze tracking and face recognition.
Similarities and differences in the kinetics of the michaelis scheme and the Henri scheme

Most steady state enzyme kinetics are consistent with the Henri scheme, (ES)E + S → E + Products, as well as with the common Michaelis scheme. The pre-steady-state time course of product can be used to distinguish between the schemes. Relaxation kinetic measurements do not offer a simple method for separating the reversible Michaelis scheme from the reversible Henri scheme.
Midterm Follow-up of Robotic Biventricular Pacing Demonstrates Excellent Lead Stability and Improved Response Rates.

BackgroundRobotically assisted left ventricular (LV) lead placement is an effective minimally invasive rescue procedure for cardiac resynchronization in the setting of failed coronary sinus lead in...
Mendelian and trans-generational inheritance in hypertensive renal disease

AbstractFamilial risk in hypertensive renal disease has stimulated a search for genetic variation contributing to this risk. The current phase of population genetic studies has sought to associate genetic variation with disease in large populations by testing genotypes at a large number of common genetic variations in the genome, expecting that common genetic variants contributing to renal disease risk will be identified. These genome-wide association studies (GWAS) have been productive and are a clear technical success. It is also clear that narrowly defined loci and genes containing variation contributing to disease risk have been identified. Further extension and refinement of these GWAS are likely to extend this success. However, it is also clear that few if any variants with substantial effects accounting for the greatest part of heritability will be uncovered by GWAS. This raises an interesting biological question regarding where the remaining heritable risk may be located. One result of the progres...
Microphysical approach to nonequilibrium dynamics of quantum fields.

We examine the nonequilibrium dynamics of a self-interacting [lambda][phi][sup 4] scalar field theory. Using a real time formulation of finite temperature field theory we derive, up to two loops and [ital O]([lambda][sup 2]), the effective equation of motion describing the approach to equilibrium. We present a detailed analysis of the approximations used in order to obtain a Langevin-like equation of motion, in which the noise and dissipation terms associated with quantum fluctuations obey a fluctuation-dissipation relation. We show that, in general, the noise is colored (time dependent) and multiplicative (couples nonlinearly to the field), even though it is still Gaussian distributed. The noise becomes white in the infinite temperature limit. We also address the effect of couplings to other fields, which we assume play the role of the thermal bath, in the effective equation of motion for [phi]. In particular, we obtain the fluctuation and noise terms due to a quadratic coupling to another scalar field.