cssi/SciSciGPT-SciSciNet huggingface dataset:
Concentration changes of polymer additives and radiolysis products in polyethylene resins irradiated at doses applicable to fresh produce

Abstract Low dose irradiation of fresh iceberg lettuce and fresh spinach is permitted in the U.S. to reduce microorganims; however, there is insufficient data on the effects of low dose irradiation on the plastic packaging for such produce. We investigated the effects of gamma irradiation at 0.5 - 20 kGy on the concentration of four antioxidants: Tris (2,4-di-tert-butylphenyl) phosphite, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(nonylphenyl) phosphite; a slip agent (erucamide); and four antioxidant radiolysis products: Tris (2,4-di-tert-butylphenyl) phosphate, 2,4-di-tert-butylphenol, tris(nonylphenyl) phosphate, and nonylphenol in polyethylene resin. Using accelerated solvent extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS), we found the concentration of antioxidants decreased as the irradiation dose increased. As the irradiation dose increased to 4 kGy, the major products associated with irradiation treatment increased. Erucamide was not significantly affected at doses less than 20 kGy. The results presented in this paper can assist with the safety evaluations of food packaging materials.
Teaching Visually Impaired College Students in Introductory Statistics

Instructors of postsecondary classes in statistics rely heavily on visuals in their teaching, both within the classroom and in resources like textbooks, handouts, and software, but this information...
Myocardial Infarction and Persistent Angina With No Obstructive Coronary Artery Disease

Abstract Women with myocardial infarction with no obstructive coronary artery disease (MINOCA) are increasingly recognized. Women with MINOCA are at high risk for major adverse cardiovascular event...
Local Corporate Law

Corporate law has long been a creature of the state legislatures, implemented largely by statutes and interpreted by courts. Only recently has the federal government entered the game via substantive governance requirements enacted in Sarbanes Oxley and Dodd-Frank. There is a significant complication to this conventional wisdom, however, which has been almost completely overlooked. Cities’ role as significant creators of corporate law is increasing, largely in the form of command-and-control mandates imposed on corporations active within a city’s limits. Cities have become involved in determining the internal composition of organizations, as city agencies have prescribed board diversity quotas in nonprofit grant conditions or diverse ownership in contract bidding requirements. Cities have also raised expectations for corporations’ community engagement through proposed community benefits ordinances and enacted percent-for-art laws that require corporations to be contributing community members. This rise of what I term “municipal corporate law” has a number of significant implications for policymakers and longstanding corporate law debates. Does the race to the bottom (or top) change once cities are in the running? Are the differing legal styles characteristic of Delaware and cities on a collision course? I consider a number of such questions and offer a preliminary evaluation of municipal corporate law.
Local anesthesia enhanced with increasing high-frequency ultrasound intensity.

The effect of local anesthetics, particularly those which are hydrophilic, such as tetrodotoxin, is impeded by tissue barriers that restrict access to individual nerve cells. Methods of enhancing penetration of tetrodotoxin into nerve include co-administration with chemical permeation enhancers, nanoencapsulation, and insonation with very low acoustic intensity ultrasound and microbubbles. In this study, we examined the effect of acoustic intensity on nerve block by tetrodotoxin and compared it to the effect on nerve block by bupivacaine, a more hydrophobic local anesthetic. Anesthetics were applied in peripheral nerve blockade in adult Sprague-Dawley rats. Insonation with 1-MHz ultrasound at acoustic intensity greater than 0.5 W/cm2 improved nerve block effectiveness, increased nerve block reliability, and prolonged both sensory and motor nerve blockade mediated by the hydrophilic ultra-potent local anesthetic, tetrodotoxin. These effects were not enhanced by microbubbles. There was minimal or no tissue injury from ultrasound treatment. Insonation did not enhance nerve block from bupivacaine. Using an in vivo model system of local anesthetic delivery, we studied the effect of acoustic intensity on insonation-mediated drug delivery of local anesthetics to the peripheral nerve. We found that insonation alone (at intensities greater than 0.5 W/cm2) enhanced nerve blockade mediated by the hydrophilic ultra-potent local anesthetic, tetrodotoxin. Graphical abstract.
When an organization violates public expectations: A comparative analysis of sustainability communication for corporate and nonprofit organizations

Abstract Applying the expectancy violation theory (EVT) to the sustainability communication context, the main purpose of the study was to explore how publics respond to an organization whose sustainable development diverges from public expectation. Specifically, this study investigated how the violating behaviors of both for-profit and nonprofit organizations influence public evaluations toward the organizations. A 2 (organization: corporation vs. nonprofit) X 2 (sustainability activity: positive vs. negative) X 2 (altruistic motive: high vs. low) between-subjects randomized experimental study was employed to address the role of publics’ attribution of organization motives in generating the expectancy violation. The results reveal that positive and negative expectancy violation, rather than positive and negative expectancy conformity, leads to more significant effects on evaluations about organizations (i.e., credibility, attitude, and supportive behavioral intention), while expectancy violation effects vary by the organization type.
Trends in the Management of Traumatic Upper Extremity Amputations.

Purpose Treatment for upper extremity amputations includes revision amputation or attempted replantation. The rate of digital replantation has been declining in the United States. Prior studies discovered the presence of socioeconomic disparities associated with these injuries. The goals of this study were to investigate yearly trends of traumatic upper extremity amputations and evaluate the presence of disparities with access to care in these injuries. Methods The 2008 to 2014 New York Statewide Planning and Research Cooperative System (SPARCS) inpatient and outpatient databases were utilized to identify patients who had traumatic upper extremity amputations. We queried the database for patient characteristics, resource utilization characteristics, insurance status, major in-hospital complications, and mortality. Patients at low-, medium-, and high-volume institutions were compared. We performed multivariable logistic regressions for the binary variable replantation (yes/no) controlling for age, sex, race, insurance status, amputation level, admission hour, and comorbidities. Results A total of 2,492 patients met our inclusion criteria: 92.1% sustained digital amputations and 7.9% sustained arm amputations. The annual rate of inpatient finger amputations decreased significantly (1.9 per 100,000 people in 2008 vs 1.4 per 100,000 people in 2014) during the study period while that of outpatient finger amputations increased significantly (12.0 per 100,000 people in 2008 vs 15.5 per 100,000 people in 2014). Multivariable analysis demonstrated incrementally lower odds for replantation with increasing age and increased odds for replantation in patients with private insurance (odds ratio, 1.64; 95% confidence interval, 1.08–2.50). The number of replantation surgeries at medium-volume institutions decreased by 45% while remaining steady in low- and high-volume institutions. Conclusions Our findings corroborate the findings of other studies that underscore the existence of disparities with respect to insurance status in these injuries. Replantations occur more frequently at high-volume hospitals and are more common in younger patients with private insurance. This finding suggests that patients with traumatic amputations may benefit from treatment at high-volume institutions. Further research to help improve access to such institutions is warranted. Type of study/level of evidence Prognostic II.
Realism Versus Antirealism in Contemporary Philosophy of Science

The scientific realism/antirealism debate in contemporary philosophy of science is about theoretical knowledge, that is, knowledge that is supposed to be about so-called “unobservables.” This includes theoretical entities, such as neutrinos and genes, as well as theoretical processes, such as natural selection and continental drift. Is theoretical knowledge in science possible? In general, scientific realists tend to think that science can (and does) yield theoretical knowledge, whereas antirealists tend to think that science cannot (and does not) yield theoretical knowledge (that is, knowledge about unobservables). To put it another way, scientific realists tend to argue that we have good reasons to believe that our best scientific theories are approximately true because, if they were not even approximately true, they would not be able to explain and predict natural phenomena with such impressive accuracy. On the other hand, antirealists tend to argue that the impressive success of our best scientific theories does not warrant belief in the approximate truth of our best scientific theories. This is because the history of science is a graveyard of theories that were once successful but were later discarded.
Heyde Syndrome–Pathophysiology and Perioperative Implications

Gastrointestinal (GI) bleeding in patients with calcific aortic valve stenosis (AVS), termed Heyde syndrome, was first described by Edward C. Heyde. The strong association between valvular replacement and the eradication of clinically significant GI bleeding confirmed an underlying pathophysiologic relationship. The rheologic stress created by AVS increases proteolysis of von Willebrand factor (VWF), resulting in loss of predominantly high-molecular-weight VWF (Hmw VWF). Angiodysplastic vessels present in patients with AVS, coupled with the lack of functioning Hmw VWF, increase the risk for GI bleeds. Aortic valve replacement, both surgical and transcatheter-based, is often a definitive treatment for GI bleeding, leading to recovery of Hmw VWF multimers. Perioperative management of patients involves monitoring their coagulation profiles with relevant laboratory tests and instituting appropriate management. Management can be directed in the following two ways: by improving internal release of VWF or by administration of external therapeutics containing VWF. It is important for perioperative physicians to obtain an understanding of the pathophysiology of this disease process and closely monitor the bleeding pattern so that targeted therapies can be initiated.
Fatigue load testing of full-scale dynamic message signs

Abstract This paper summarizes results acquired from the fatigue testings of two full-scale dynamic message signs (DMSs) fabricated by a local manufacturer in the United States. One DMS with adhesive joints and one DMS with welded joints were tested with fatigue loading. For the testing, each of the DMSs was loaded up to 500,000 cycles with a force ranging between 0.249 kN and 0.818 kN equivalent to the design natural wind gust pressure based on a yearly mean speed of 18.02 km/h according to the AASHTO LRFD Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals. Strain, displacement, and load were recorded during each test to analyze the structural adequacy of tested DMSs. During the testing, all the stress ranges observed in each of the tested DMSs were considerably below the threshold of the DMS panel, which was determined by generating its S-N curves. The maximum deflection range was found to be highest near the center for both adhesive and welded DMSs when encountered with the fatigue loads. It is recommended that additional stiffeners be installed to reduce the deflection range of the DMS at the center. It was also found that any damage was not observed in both the adhesive and welded DMSs due to the fatigue loading.
Temperature Dependence of Electron and Hole Impact Ionization Coefficients in GaN

The temperature dependence of the electron and hole impact ionization coefficients in GaN has been investigated experimentally. Two types of p-i-n diodes grown on bulk GaN substrates have been fabricated and characterized, and the impact ionization coefficients for both electrons and holes have been extracted using the photomultiplication method. Both the electron and hole impact ionization coefficients decrease as the temperature increases. The Okuto–Crowell model was used to describe the temperature dependence of the electron and hole impact ionization coefficients. Based on the measured impact ionization coefficients, the temperature dependence of the breakdown voltage of GaN non-punch through p-n diodes can be predicted; good agreement with experimentally reported results is obtained.
Cost-effectiveness analysis of optimal diagnostic strategy for patients with symptomatic cholelithiasis with intermediate probability for choledocholithiasis.

Abstract Background and Aims Endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and intraoperative cholangiogram (IOC) are the recommended diagnostic modalities for patients with intermediate probability for choledocholithiasis (IPC). The relative cost-effectiveness of these modalities in patients with cholelithiasis and IPC is understudied. Methods We developed a decision tree for diagnosing IPC (base case probability: 50%; range 10%-70%); patients with a positive test were modeled to undergo therapeutic ERCP. The strategies tested include (1) Laparoscopic cholecystectomy with IOC (LC-IOC), (2) MRCP, (3) single-session EUS + ERCP, and (4) separate session EUS + ERCP. Costs and probabilities were extracted from the published literature. Effectiveness was assessed by (1) assigning utility scores to health states, (2) the average proportion of true positive diagnosis of IPC, and (3) the mean length of stay (LOS) per strategy. Cost-effectiveness was assessed by extrapolating a net-monetary benefit (NMB), and average cost per true positive diagnosis. Results LC-IOC was the most cost-effective strategy to diagnose IPC (base-case probability of 50%) among patients with cholelithiasis in health state-based effectiveness analysis (NMB of $34,612), diagnostic test accuracy-based effectiveness analysis (average cost of $13,260 per true positive diagnosis), and LOS-based effectiveness analysis (mean LOS of 4.13) compared with strategy 2 (MRCP), 3 (single-session EUS+ERCP), and 4 (separate-session EUS+ERCP). These findings were robust on deterministic and probabilistic sensitivity analyses. Conclusion For patients with cholelithiasis with IPC, LC-IOC is a cost-effective approach that should limit preoperative testing and may shorten length of hospital stay. Our findings may be used to design institutional and organizational management protocols.
Political appointees vs. elected officials: Examining how the selection mechanism for state governing agency board members influences responsiveness to stakeholders in higher education policy-making

Through an exploratory comparative case study of two U.S. states (Georgia and Nevada), this study investigates how the selection mechanism to state higher education governing agency boards influences the responsiveness of board members to stakeholders and their role in the policy-making process. Framed around the recent national policy agenda to improve postsecondary degree attainment and college completion, findings suggest that state agency board members in both states prioritized the opinions, insights, and goals of the state governor and governing agency staff, regardless of selection mechanism. However, for more localized issues and on-the-ground decision-making, stakeholders formally involved in the day-to-day operation of higher education, such as administrators, faculty, and students, serve a larger role, though this influence can be mediated by the selection mechanism of board members.
Electrocatalytic H2O2 generation for disinfection

Abstract Epidemics are threatening public health and social development. Emerging as a green disinfectant, H2O2 can prevent the breakout of epidemics in migration. Electrochemical H2O2 production powered by renewable electricity provides a clean and decentralized solution for on-site disinfection. This review firstly discussed the efficacy of H2O2 in disinfection. Then necessary fundamental principles are summarized to gain insight into electrochemical H2O2 production. The focus is on exploring pathways to realize a highly efficient H2O2 production. Progress in advanced electrocatalysts, typically single-atom catalysts for the two-electron oxygen reduction reaction (2e− ORR), are highlighted to provide high H2O2 selectivity design strategies. Finally, a rational design of electrode and electrolytic cells is outlined to realize the on-site disinfection. Overall, this critical review contributes to exploiting the potentials and constraints of electrochemical H2O2 generation in disinfection and pinpoints future research directions required for implementation.
Control of Nitrogen Assimilation by the NRI-NRII Two-Component System of Enteric Bacteria

Enteric bacteria such as Escherichia coli, Salmonella typhimurium, and their relatives regulate the expression of glutamine synthetase (GS) and other enzymes important in nitrogen assimilation in response to changes in the availability of nitrogen. In this review, the current state of knowledge about the mechanisms of signal transduction by NRI and NRII is summarized briefly. Escherichia coli and related bacteria precisely regulate the level of GS activity by three distinct mechanisms. First, the intracellular concentration of the enzyme is regulated in response to the intracellular nitrogen status. Second, the activity of the enzyme is regulated by reversible covalent modification. Finally, the activity of GS is allosterically controlled by cumulative feedback inhibition by eight small molecules: tryptophan, histidine, carbamyl phosphate, glucosamine-6-phosphate, CTP, AMP, alanine, and glycine. A hypothesis to explain the different phenotypes resulting from the suppressor mutations in glnL is as follows: the suppressors resulting in the constitutive expression of glnA are likely to have either eliminated the capacity of NRII to interact with PII or rendered this interaction unproductive in bringing about the regulated phosphatase activity. The authors examined the ability of partially modified PII to elicit the regulated phosphatase activity and found that it was partially active. They also examined the ability of immobilized NRII to retain PII, using a column chromatography method.
Association of integrated metabolic pathways with membranes. I. Glycolytic enzymes of the red blood corpuscle and yeast.

Abstract Fractionation of hemolyzed beef erythrocytes, and of broken cells of Saccharomyces cerevisiae , yielded membranous entities which catalyzed the complete glycolytic series of reactions without supplementation by way of enzymes. In the erythrocyte membrane the over-all glycolytic activity per milligram of protein, was concentrated 24 times with reference to the same activity in the whole hemolysate. A wide divergence was found in the firmness of the association of individual glycolytic enzymes with the erythrocyte membrane under the conditions of isolation. Some, like triosephosphate dehydrogenase, were completely retained in the membrane fraction; others, especially the nonrate-limiting isomerases, were recovered on the membrane in very low yield. However, the glycolytic enzymes of yeast exhibited no such wide divergency of affinity for the yeast membrane under the conditions used. In the case of the erythrocyte, modification of the methods used in rupture of the cell and isolation of the membrane markedly altered the pattern of activities retained by the membrane. Triosephosphate dehydrogenase could be extracted from and readily recombined with the membrane. The glycolytic complex of enzymes bound to the erythrocyte membrane was also resolved, and reassembled, by a simple cycle of pH changes. It is concluded that in the intact cell the complete glycolytic complex of enzymes is associated with the plasma membrane and is not in free solution.
Quantum Simulations as a Tool for Predictive Nanoscience

In the last two decades, the coming of age of first principles theories of condensed and molecular systems, and the continuous increase in computer power have positioned physicists to address anew the complexity of matter at the microscopic level. Theoretical and algorithmic developments in ab initio molecular dynamics [1] and quantum Monte Carlo methods [2], together with optimized codes running on high-performance computers, have allowed many properties of matter to be inferred from the fundamental laws of quantum mechanics, without input from experiment.
A Discrete Lagrangian-Based Global-SearchMethod for Solving Satisfiability Problems

Satisfiability is a class of NP-complete problems that model a wide range of real-world applications. These problems are difficult to solve because they have many local minima in their search space, often trapping greedy search methods that utilize some form of descent. In this paper, we propose a new discrete Lagrange-multiplier-based global-search method (DLM) for solving satisfiability problems. We derive new approaches for applying Lagrangian methods in discrete space, we show that an equilibrium is reached when a feasible assignment to the original problem is found and present heuristic algorithms to look for equilibrium points. Our method and analysis provides a theoretical foundation and generalization of local search schemes that optimize the objective alone and penalty-based schemes that optimize the constraints alone. In contrast to local search methods that restart from a new starting point when a search reaches a local trap, the Lagrange multipliers in DLM provide a force to lead the search out of a local minimum and move it in the direction provided by the Lagrange multipliers. In contrast to penalty-based schemes that rely only on the weights of violated constraints to escape from local minima, DLM also uses the value of an objective function (in this case the number of violated constraints) to provide further guidance. The dynamic shift in emphasis between the objective and the constraints, depending on their relative values, is the key of Lagrangian methods. One of the major advantages of DLM is that it has very few algorithmic parameters to be tuned by users. Besides the search procedure can be made deterministic and the results reproducible. We demonstrate our method by applying it to solve an extensive set of benchmark problems archived in DIMACS of Rutgers University. DLM often performs better than the best existing methods and can achieve an order-of-magnitude speed-up for some problems.
State reduction and call admission in multirate circuit-switched networks

In a circuit (real, or virtual) switching network, call admission control plays a central role in determining the throughput and grade of service of a network. This issue, of course, is not new, but the characteristics of multirate and high speed of a broadband integrated service digital network (ISDN) make the problem quite different from its counterpart in a telephone (single-rate) network. The tremendous number of states, created by the huge bandwidth of a broadband network and its multirate characteristic, makes the design and analysis of call admission policies in a broadband network computationally intractable. We propose a state grouping method to reduce the total number of states. An important characteristic of the method is that the total gain of a policy remains unchanged in the reduced state space. This means that the search for a better policy can be conducted in the reduced state space created by the state reduction method. The time complexity is drastically reduced.
Comparative analysis of backpropagation and extended Kalman filter in pattern and batch forms for training neural networks

The extended Kalman filter (EKF) algorithm has been used for training neural networks. Like the backpropagation (BP) algorithm, the EKF algorithm can be in pattern or batch form. But the batch form EKF is different from the gradient averaging in standard batch mode BP. The paper compares backpropagation and extended Kalman filter in pattern and batch forms for neural network trainings. For each comparison between the batch-mode EKF and BP, the same batch data size is used. An overall RMS error computed for all training examples is adopted in the paper for the comparison, which is found to be especially beneficial to pattern mode EKF and BP trainings. Simulation of the network training with different batch data sizes shows that EKF and BP in batch-form usually are more stable and can obtain smaller RMS error than in pattern-form. However, too large batch data size can let the BP trap to a "local minimum", and can also reduces the network training effect of the EKF algorithm.
Recent developments in synthetic elastomers

This paper reviews the changes which have occurred from 1965 to 1970 in synthetic elastoiners, principally from the view of new products, emphasizing the scientific trends involved. Subjects covered include diene rubbers, ethylene/propylene copolymers and particularly the various specialty type elastomers, including liquid and thermoplastic block copolymers. The trend towards precise control of elastorner structure and of monomer sequence, configuration, and orientation in the growing chain is emphasized. Diese Veroffentlichung beschreibt zusammenfassend die Anderungen, die auf dom Gebiet der synthetischen Elastomeren von 1965–1970 stattgefunden haben, vorwiegend im Hinblick auf neue Produkte und mit besonderer Betonung der damit die Gebiete der Dien-Kautschuke, Athylen/Propylen-Copolymere und besonders verschiedene Sondertypen von Elastomeren, einschlieslich flussiger und thermoplastischer Block-Copolymere eroUrtert. Das Bestreben, die Struktur des Elastomeren sowie Monomerenfolge, konfiguration und Orientierung der wachsenden Kette genau zu kontrollieren, wird betont.
Sintering kinetics and transport property evolution of large multi-particle aggregates

Ultrafine (“nano”-) particles produced from highly supersaturated vapors or liquids are usually aggregated, often containing thousands of small 'primary’ particles bound together in tenuous structures characterized by mass fractal dimensions less than 3. Such aggregates have large initial surface area but are metastable with respect to more compact configurations. Available restructuring mechanisms include surface energy driven coalescence, which, in the case of viscous flow at high gas temperatures, is ultimately able to obliterate all evidence of the original (“primary”) particles. We here exploit the notion that, provided an aggregate is sufficiently large, it can be treated like a spatially non-uniform porous medium, undergoing finite-rate surface energy driven viscous flow sintering leading to final collapse to a single dense sphere. For this purpose, after a D ƒ ≌s const stage of sintering [associated with a corresponding increase in mean apparent primary particle ('grain’) size], we use an extensio...
Probability of plume interception using conditional simulation of hydraulic head and inverse modeling

A procedure to estimate the probability of intercepting a contaminant groundwater plume for monitoring network design has been developed and demonstrated. The objective of the procedure is to use all available information in a method that accounts for the heterogeneity of the aquifer and the paucity of data. The major components of the procedure are geostatistical conditional simulation and parameter estimation that are used sequentially to generate flow paths from a suspected contaminant source location to a designated monitoring transect. From the flow paths, a histogram is constructed that represents the spatial probability distribution of plume centerlines. With an independent estimate of the plume width, a relationship between the total cost and the probability of detecting a plume can be made. The method uses geostatistical information from hydraulic head measurements and is conditioned by the data and the physics of groundwater flow. This procedure was developed specifically for the design of monitoring systems at sites where very few, if any, hydraulic conductivity data are available.
A novel protein produced by the vitellogenic fat body and accumulated in mosquito oocytes.

The fat body of vitellogenic mosquitoes was found to synthesize and secrete another protein in addition to vitellogenin, that accumulated in developing oocytes. In the tissues, this protein has Mr = 53000 on SDS-PAGE under reducing or non-reducing conditions. This protein is glycosylated as shown by [3H]mannose incorporation and experiments with tunicamycin. Polyclonal antibodies were produced using the ovarian 53-kDa peptide. Immunoblot analysis demonstrated the immunological identity of 53 kDa peptides from the fat body and the ovary. Furthermore, the 53-kDa protein (53KP) is synthesized and secreted exclusively by the vitellogenic fat body. Radioimmunoassay showed that 53KP is produced by the female fat body as early as 4 h and reaches its peak near 24 h after the initiation of vitellogenesis. Synthesis then drops to low levels by 36 h and declines to background levels by 48 h. In vitro experiments conducted on fat bodies of previtellogenic females demonstrated that the synthesis and secretion of 53KP can be stimulated by a physiological dose of 20-hydroxyecdysone (10-6 M). Immunocytochemical studies of the ovary demonstrate that 53KP is present in channels between follicle cells, in the perioocytic space and in yolk granules of the developing oocytes. This suggests that 53KP is accumulated in the oocytes by a pathway similar to that of vitellogenin.
Dislocation core structures and yield stress anomalies in molybdenum disilicide

Abstract Stacking fault energies in MoSi2 due to shear along have been calculated by modified embedded atom method (MEAM) calculations. Preliminary calculations have also been made of dislocation core structures and their response to applied stress. The results are used to investigate the configuration and mobility of 1/2 dislocations. Shear of 1/6 in the {103} plane of MoSi2 produces an anti-phase boundary (APB) whose geometry, called APB(1), is different from that produced by 1/6 in the opposite direction, APB(2). Calculations show that APB(1) is stable and APB(2) is unstable. MEAM calculations show that there is a stable fault close to APB(2) with a displacement of ∼1/8 in the same direction. The {103} planes have an unusual five layer stacking sequence with successive planes offset by 1/5 . Shear of 1/10 in the correct direction gives a low energy intrinsic fault. This vector is close to the 1/8 shear that produces a stable fault. Various dissociated configurations of 1/2 dislocations are considered based on these partials. All can have asymmetrical arrangements which will respond differently to the direction of the applied stress, explaining the yield stress asymmetry in MoSi2. All of the slip systems ( {0kl} and {110} as well as {103}) exhibit yield stress anomalies at different temperatures. Different core configurations at high and low temperatures are used to explain the phenomena.
Task Analysis of Aircraft Inspection Activities: Methods and Findings

Unless the U.S. commercial aircraft fleet is maintained with high reliability, we cannot be assured of flight safety with an ageing fleet. Maintenance depends upon inspection to be effective, thus ...
Experimental Rhinovirus 16 Infection Potentiates Histamine Release after Antigen Bronchoprovocation in Allergic Subjects

Viral respiratory infections exacerbate asthma in many patients. We hypothesized that one mechanism by which this effect occurs may include potentiated or altered mediator release by mast cells and/or basophils to favor the development of late-phase asthmatic reactions (LAR). Therefore, we studied eight subjects with allergic rhinitis before and during an experimentally induced rhinovirus 16 (RV16) infection. We determined levels of plasma histamine and tryptase, and we observed the associated patterns of airway obstruction that developed following inhaled antigen challenge. Bronchial responsiveness to histamine, methacholine, and antigen were all significantly increased during the RV16 illness. Further, the incidence of LAR was significantly higher (five of eight) during the infection than before (one of eight; p = 0.014). In addition, in those patients whose pattern of response following antigen challenge converted from an immediate response only before infection to a dual response (immediate + late pha...
Embryonic Appearance of α, β, and γ Crystallins in the Periodic Albinism (ap) Mutant of Xenopus laevis

The appearance of the crystallins during lens development in the periodic albinism (ap/ap) mutant of Xenopus laevis has been studied. Using antibodies specific for total crystallins, α + β crystallins, and γ crystallins in the immunofluorescence technique, the first positive reaction for all could be demonstrated in the Nieuwkoop-Faber Stage 31 lens rudiment. The antibody to α + β crystallins exhibited differences in intensity from cell to cell in the early rudiment, while the reaction to the other antibodies was uniform throughout the rudiment. As lens differentiation progressed, immunofluorescence was restricted in all cases to the lens fiber area, up to and including Nieuwkoop-Faber Stage 45. The lens epithelium of the one-year-old adult ap/ap was positive, however, for total lens crystallins. These results are at variance with earlier studies on lens development and the crystallins in wild-type (+/+) X. laevis, where a positive reaction for y and total crystallins could be detected earlier, and in the lens epithelium of Nieuwkoop-Faber Stage 41 embryos for total lens crystallins. That this divergence in the mutant is due to a pleiotropic effect or directly to the inductive failure of the endomesoderm to initiate melanogenesis, is discussed.
Automatic Data Plotting Method for Functions of Many Variables

A general method for automatically plotting a function of many variables is described. The variables, as analog signals, are sampled by a voltage-sensor circuit, and data are recorded only when the variables are at predetermined values. Presentation is on an intensity modulated X-Y oscilloscope. Thus if y = y(x 1 , x 2 , ..., x n ), then graphical displays can be made of y versus any two variables, with the remaining variables at fixed predetermined values. Mathematical inversion is possible, and solutions obtained for x p (x 1 ,..., x p-1 , x p+1 ,...,x n , y) as a function of y and any one of the other variables, and the inversion need not be single valued. Examples of two-dimensional and three-dimensional displays are given, with the axes rotated and viewed from different ``perspectives.''
Quantum gravity Hamiltonian for manifolds with boundary.

In canonical quantum gravity, when space is a compact manifold with boundary there is a Hamiltonian given by an integral over the boundary. Here we compute the action of this ``boundary Hamiltonian'' on observables corresponding to open Wilson lines in the new variables formulation of quantum gravity. In cases where the boundary conditions fix the metric on the boundary (e.g., in the asymptotically Minkowskian case) one can obtain a finite result, given by a ``shift operator'' generating translations of the Wilson line in the direction of its tangent vector. A similar shift operator serves as the Hamiltonian constraint in the work of Morales-T\'ecotl and Rovelli on quantum gravity coupled to Weyl spinors. This suggests the appearance of an induced field theory of Weyl spinors on the boundary, analogous to that considered in Carlip's work on the statistical mechanics of the (2+1)-dimensional black hole. \textcopyright{} 1995 The American Physical Society.
Synthesis, Structure, and In Vitro Anti-HIV Activity of New Pyrazole, 1,2,4-Thiadiazole, and 1,2,4-Triazole Derivatives

α,α′-Dichloroazo compounds 6 react with Lewis acid to furnish 1-(chloroalkyl)-1-aza-2-azoniaallene salts 4. The cations 4 react with acetylenes, isothiocyanates, isocyanates, and carbodiimides under [3+2]-cycloaddition. The cycloadducts undergo consecutive reactions, e.g., [1,2]-shifts of alkyl groups. The newly synthesized products were evaluated for their anti-HIV-1 and anti-HIV-2 activity in MT-4 cells.
All-diode generation and amplification of 10 GHz pulse-trains from coupled-cavity mode-locked lasers using Slab-Coupled Waveguide Amplifiers

Compact sources of low noise multi-gigahertz pulse-trains and frequency combs are useful in applications such as optical arbitrary waveform generation and high speed analog to digital conversion [1–3]. Low pulse-to-pulse timing and amplitude jitter are essential to these applications. Additionally, applications requiring portability benefit from the use of semiconductor gain media. In this work, we present an actively mode-locked laser and an amplification stage both using Slab-Coupled Optical Waveguide Amplifiers (SCOWAs) [4–6] as gain media. The mode-locked laser is built with a nested cavity design with a long optical fiber cavity and high finesse Fabry-Perot etalon (FPE). The output from this laser consists of a low-noise frequency comb with 10 GHz mode spacing and, in the time domain, a high repetition rate, low-noise pulse-train. The incorporation of SCOW amplifiers into this laser architecture has resulted in improved performance both in available power and timing jitter [5,6]. Furthermore, an external SCOWA has been used to amplify the output pulse-train and we have obtained a maximum output power of ∼390 mW. The signal degradation through the amplification stage is studied and no considerable degradation is observed in the timing jitter and spectral bandwidth of the output comb.
A quadripotential mesenchymal progenitor cell isolated from the marrow of an adult mouse

Adult marrow contains mesenchymal progenitor cells (MPCs) that have multiple differentiation potentials. A conditionally immortalized MPC clone, BMC9, has been identified that exhibits four mesenchymal cell phenotypes: chondrocyte, adipocyte, stromal (support osteoclast formation), and osteoblast. The BMC9 clone, control brain fibroblasts and another marrow-derived clone, BMC10, were isolated from a transgenic mouse (H-2Kb-tsA58) containing a gene for conditional immortality. To test for chondrogenic potential, cells were cultured in defined medium containing 10 ng/ml transforming growth factor beta and 10-7 M dexamethasone in 15-ml polypropylene tubes ("aggregate cultures"). Adipogenic potential was quantitated by flow cytometry of Nile Red-stained cells cultured for 1 and 2 weeks in medium containing isobutyl methylxanthine, indomethacin, insulin, and dexamethasone. Support of osteoclast formation was measured by quantitating multinucleated tartrate-resistant acid phosphatase-positive cells in spleen cell cocultures of test clones (immortomouse clones and positive control ST2 cells) cultured in the presence of 10-7 M vitamin D3 and 150 mM ascorbate-2-phosphate. In vivo osteogenic potential was assayed by histologic examination of bone formation in subcutaneous implants, into athymic mouse hosts, of a composite of cells combined with porous calcium phosphate ceramics. The bone marrow-derived clone BMC9 has the potential to express each of the four mesenchymal characteristics tested, while brain fibroblasts, tested under identical conditions, did not exhibit any of these four mesenchymal characteristics. BMC10 cells exhibited osteogenic and chondrogenic phenotypes, but showed only minimal expression of adipocytic or osteoclast-supportive phenotypes. Clone BMC9 is, minimally, a quadripotential MPC isolated from the marrow of an adult mouse that can differentiate into cartilage and adipose, support osteoclast formation, and form bone. The BMC9 clone is an example of an adult-derived multipotential progenitor cell that is situated early in the mesenchymal lineage.
Coronary hemodynamic and myocardial metabolic alterations accompanying coronary spasm

Abstract Arterial pressure, coronary sinus blood flow with the thermodilution technique and calculated coronary vascular resistance were measured and coronary arteriography performed at rest and after the administration of ergonovine in 14 patients with atypical chest pain (group I) and 6 patients with variant angina (group II). Mild diffuse narrowing of the left coronary bed in group I was not accompanied by S-T segment shifts, and coronary vascular resistance did not change significantly. In contrast, severe focal spasm (greater than 90 percent narrowing) of the left anterior descending coronary artery in group II patients was accompanied by S-T elevation and a marked overall increase in coronary vascular resistance (from 0.65 ± 0.07 to 1.14 ± 0.10 mm Hg/ml per min) ( P
Influence of sea ice on the thermohaline circulation in the Arctic‐North Atlantic Ocean

A fully prognostic coupled ocean-ice model is used to study the sensitivity of the overturning cell of the Arctic-North-Atlantic system to sea ice forcing. The strength of the thermohaline cell will be shown to depend on the amount of sea ice transported from the Arctic to the Greenland Sea and further to the subpolar gyre. The model produces a 2–3 Sv increase of the meridional circulation cell at 25N (at the simulation year 15) corresponding to a decrease of 800 km³ in the sea ice export from the Arctic. Previous modeling studies suggest that interannual and decadal variability in sea ice export of this magnitude is realistic, implying that sea ice induced variability in the overturning cell can reach 5–6 Sv from peak to peak.
Qualitative interpretive meta-synthesis in social work research: Uncharted territory

SummaryThe authors present the field of social work with a methodology specifically aimed at the synthesis of qualitative research informed by existing methods and applications yet tailored to the unique values and goals of the profession of social work.FindingsThough qualitative research in social work is commonplace, currently, the field lacks a methodology to synthesize these qualitative studies. A synthesis of qualitative studies results in generation of a more in-depth understanding of the phenomena studied that can be used to develop theory and inform practice and policy.ApplicationsThis methodology enables synergistic understanding of phenomena with richness in diversity of settings, participants, and qualitative traditions. This synergistic understanding can be used to develop theory and inform practice and policy.
Shaken, but Alive: Organizational Behavior in the Wake of Catastrophic Events

When faced with survival-threatening catastrophic events, organizations are often advised to adopt radical, frame-breaking changes. However, evidence suggests threatened organizations tend to do exactly the reverse: they are rigid and detached, relying on existing strategies, routines and resources to pull them through, and then — if they survive — coping with problems once the threat has passed. This article explores the parallels between organizational crisis behavior and individual behavior in the wake of traumatic events, as described in the clinical theory of "post-traumatic stress disorder" (PTSD). Using Man ville Corporation's asbestos crisis to illustrate the theory, it is proposed that environmental catastrophes produce trauma by contradicting and invalidating strongly held organizational paradigms, or "world views". Although radical changes may be needed to rebuild organizational world views, trauma-related rigidity and detachment preclude such changes, making survival doubly problematic. As an alternative to radical change, the article proposes "behavioral self-blame" as a realistic intermediate solution for threatened organizations, and discusses the implications of this solution for researchers, practitioners and organizational change-agents.
Biodegradation of unsaturated poly(ester-amide)s and their hydrogels

Abstract The biodegradability of both unsaturated (UPEA) and saturated (SPEA) poly(ester-amide)s and a series of hydrogels (UPEA-G) fabricated from UPEA and poly(ethylene glycol) diacrylate (PEG-DA) was examined as a function of PEA chemical structures in both phosphate buffered saline (PBS) and α -chymotrypsin solutions. Based on the weight loss data, α -chymotrypsin had a much more profound effect on the hydrolyses of UPEA, SPEA polymers (up to 32% weight loss on day 1 for FPBe) and UPEA-G hydrogels (up to 32% weight loss on day 31 for FPBe-G28) than a PBS buffer (less than 10% for polymers and 16% for hydrogels). The changes in elastic moduli and the interior morphology of the hydrogels in both PBS buffer and α -chymotrypsin solutions were also monitored for 2 months, and the hydrogels’ crosslinking density ( n e ) and molecular weight between crosslinks ( M c ) before and after biodegradation were then examined as a function of biodegradation time, enzyme concentration, and different chemical structure of precursors. The differences in biodegradation rates among PEA polymer and UPEA-G hydrogels are ascribed to differences in hydrophilicity and saturated or unsaturated structure of the polymers and hydrogel precursors. Our results showed that, by changing the concentration of α -chymotrypsin, the type of UPEA precursors and their feed ratio, the UPEA-G hydrogels could have controllable biodegradability, which is quite desirable for a wide range of biomedical and pharmaceutical applications.
Hereditary spastic paraplegia-causing mutations in atlastin-1 interfere with BMPRII trafficking

Disruption of the bone morphogenic protein (BMP)-linked signaling pathway has been suggested as an important factor in the development of hereditary spastic paraplegia (HSP). HSP-causing proteins spastin, spartin and NIPA1 were reported to inhibit the BMP pathway. We have previously shown a strong interaction of NIPA1 and atlastin-1 proteins. Hence, we investigated the role of another HSP-associated protein atlastin-1 in this signaling cascade. Endogenous and expressed atlastin-1 showed a strong interaction with BMP receptors II (BMPRII) and analyzed missense, HSP-causing mutations R239C and R495W disrupted BMPRII trafficking to the cell surface. BMPRII does not require the presence of atlastin-1 because knockdown expression of atlastin-1 did not alter endogenous BMPRII cellular distribution. Expression of mutant forms of atlastin-1 also interfered with the signaling response to BMP4 stimulation and reduced phosphorylation of Smad 1/5 proteins. Our results suggest that HSP-causing atlastin-1 mutations exhibit a dominant-negative effect on trafficking of BMPRII, which disrupts the BMP pathway in neurons. This, together with previously demonstrated inhibition of atlastin-1 of BMP pathway, further supports the role of this signaling cascade in axonal maintenance and axonal degeneration, which is seen in various types of HSP.
Ablation of skin tissue by nanosecond laser pulses at 1064, 532, 266, and 213 nm

The ablation of porcine skin tissue has been investigated using nanosecond (ns) laser pulses at the wavelengths of 1064, 532 and 266 nm. The ablation probability has been measured near the threshold through detection of the secondary radiation from the tissue sample surface at different wavelengths. Experimental results have indicated that the ablation of the skin tissue in the wide range of ablating wavelength is caused by optical breakdown induced by the strong electromagnetic field of the nanosecond pulses. Furthermore, we conclude that the initial seed electrons acquire ionization energy from the incident optical field mainly through a momentum-relaxing drift mechanism.