cssi/SciSciGPT-SciSciNet huggingface dataset:
What Is the Best Time to Initiate Peri-Operative Heparin Therapy In General Surgery Patients? A Risk-Benefit Dilemma.

Abstract Abstract 1088 Background: While many studies support the use of prophylactic heparin therapy around the time of operation in cancer patients, little data shows the optimal timing of such therapy in general surgery (GS) patients. Methods: From 2001–2008, 95 patients identified with thromboembolism reported in our GI/General Surgery Division and were compared with a matched control group for: age, gender, type of operation, date of operation, diagnosis of malignancy, and BMI. Timing of heparin therapy, characteristics of TE or bleeding events, driving distance from our institution, history of smoking or OCP use, anticoagulation use after operation, length of hospital stay, and mortality were collected. Peri-operative heparin therapy was defined as heparin given within a 24 hr window of incision. The McNemar's test for proportions was performed. Conditional logistic regression was used for the analysis of risk factors and survival curves were implemented for mortality comparisons. Results: mean age and BMI were similar (57 yrs, 33 kgM-2), 45% were female and 53% had malignancy in both groups. Duration of operation was similar (204 vs. 191 minutes, P=NS). peri-operative heparin administration was similar in the two groups (56%, 64%, p=0.05). But, pre-operative therapy was seen more in the control group (77% vs. 51%, p=0.01). Regression model showed a protective effect for heparin if it was given pre-operatively (OR=0.37, p=0.047) with no effect if it was given beyond 10 hours. Mean blood transfusion units (97 and 106 mL) and hemorrhagic events (4.5% and 5%) were similar (p=NS). Median (range) length of hospital stay was longer (19 days (0-201) vs. 6 (0-66), p=0.001) and two-year survival lower in the TE group (p=0.03). Conclusions: data from our institutional case-control study shows that heparin administration before GS is associated with more than 2-fold reduction in the risk of thromboembolism. The optimal period appears to be between 1–10 hours prior to the time of incision. Large prospective trials need to be desgined to more accurately determine the time of heparin therapy. Disclosures: No relevant conflicts of interest to declare.
A structured approach to uncertainty analysis of predictive models of engine-out NOx emissions

Predictive models of engine-out NOx emissions continue to be a topic of active research in the diesel powertrain community. Renewed interest in the use of in-cylinder pressure sensor has presented ...
Cysteine mutagenesis in the voltage-dependent sodium channel structural insights and implications.

The superfamily of ion channel proteins comprise multisubunit transmembrane glycoproteins that are the fundamental electrical signaling molecules in the heart and other excitable tissues. The large size and hydrophobicity of these proteins present a formidable obstacle to the generation of a crystal structure. In lieu of a high-resolution structure, complementary methods have been used to study the structure function relationships of these essential excitability proteins. Molecular cloning and biophysical analysis of heterologously expressed wild-type and mutant channel proteins have provided insights into the structural basis of the essential channel functions of permeation and gating. This powerful combination of techniques also provides dynamic structural information regarding channel proteins not likely to be forthcoming from a crystal structure. (Trends Cardiovasc Med 1997;7:211–218). © 1997, Elsevier Science Inc.
Insights into the localization and function of myomaker during myoblast fusion

Multinucleated skeletal muscle fibers form through the fusion of myoblasts during development and regeneration. Previous studies identified myomaker (Tmem8c) as a muscle-specific membrane protein essential for fusion. However, the specific function of myomaker and how its function is regulated are unknown. To explore these questions, we first examined the cellular localization of endogenous myomaker. Two independent antibodies showed that whereas myomaker does localize to the plasma membrane in cultured myoblasts, the protein also resides in the Golgi and post-Golgi vesicles. These results raised questions regarding the precise cellular location of myomaker function and mechanisms that govern myomaker trafficking between these cellular compartments. Using a synchronized fusion assay, we demonstrated that myomaker functions at the plasma membrane to drive fusion. Trafficking of myomaker is regulated by palmitoylation of C-terminal cysteine residues that allows Golgi localization. Moreover, dissection of the C terminus revealed that palmitoylation was not sufficient for complete fusogenic activity suggesting a function for other amino acids within this C-terminal region. Indeed, C-terminal mutagenesis analysis highlighted the importance of a C-terminal leucine for function. These data reveal that myoblast fusion requires myomaker activity at the plasma membrane and is potentially regulated by proper myomaker trafficking.
Exploiting the 3-Aminopropyltriethoxysilane (APTES) autocatalytic nature to create bioconjugated microarrays on hydrogen-passivated porous silicon.

Abstract Porous silicon (pSi) based microarrays are attractive because pSi: (i) can be modified in many ways, (ii) possesses a high surface area, and (iii) exhibits strong photoluminescence (PL). These characteristics make pSi-based microarrays candidates for a host of applications including sensing, optoelectronic devices, and photodetectors. Microarray fabrication requires a high-throughput approach to produce chemically modified, spatially isolated spots on a particular substrate. The most stable platforms are characterized by covalent attachment to the substrate. In this paper we exploit the autocatalytic nature of 3-aminopropyltriethoxysilane (APTES) to contact pin-print APTES directly onto as prepared, H-passivated pSi (ap-pSi) without the need for a formal oxidation step. We assess the APTES-derived spots by using PL and Fourier transform infrared spectroscopy (FT-IR) imaging and determine the spot size and spatial homogeneity. All APTES-derived spots exhibited two distinct regions; a silanized core surrounded by an oxidized halo. By decreasing the APTES concentration and increasing the acid concentration, the oxidized halo size decreased by 60%; however, the silanized core diameter remains APTES and acid concentration independent. Bioconjugation can be achieved to all APTES-derived features; however, the highest biomolecule loading was realized by using pure APTES. Together these experiments demonstrate an easy and simple strategy for creating protein microarrays on pSi.
Protein Folding and the Challenges of Maintaining Endoplasmic Reticulum Proteostasis in Idiopathic Pulmonary Fibrosis

Alveolar epithelial type II (AEII) cells are "professional" secretory cells that synthesize and secrete massive quantities of proteins to produce pulmonary surfactant and maintain airway immune defenses. To facilitate this high level of protein synthesis, AEII cells are equipped with an elaborate endoplasmic reticulum (ER) structure and possess an abundance of the machinery needed to fold, assemble, and secrete proteins. However, conditions that suddenly increase the quantity of new proteins entering the ER or that impede the capacity of the ER to fold proteins can cause misfolded or unfolded proteins to accumulate in the ER lumen, also called ER stress. To minimize this stress, AEII cells adapt by (1) reducing the quantity of proteins entering the ER, (2) increasing the amount of protein-folding machinery, and (3) removing misfolded proteins when they accumulate. Although these adaptive responses, aptly named the unfolded protein response, are usually effective in reducing ER stress, chronic aggregation of misfolded proteins is recognized as a hallmark feature of AEII cells in patients with idiopathic pulmonary fibrosis (IPF). Although mutations in surfactant proteins are linked to the development of ER stress in some rare IPF cases, the mechanisms causing protein misfolding in most cases are unknown. In this article, we review the mechanisms regulating ER proteostasis and highlight specific aspects of protein folding and the unfolded protein response that are most vulnerable to failure. Then, we postulate mechanisms other than genetic mutations that might contribute to protein aggregation in the alveolar epithelium of IPF lung.
Classical Theories of Generation in the Renaissance

Plato, Hippocrates, Galen and Aristotle – the four main classical examples – are considered as sources for the speculation surrounding the question of generation in the Renaissance They are important as the most accessible, and by far the most valued, of the classical authorities on generation known to Renaissance writers. Part I tries to make clear the answers of the four writers to such questions as: how is the semen formed? where, and of what substance? how does it transmit life, organised form and even detailed likeness to the offspring? how are the parts of the foetal body generated and distinguished? what does each parent contribute to this process? It also hopes to suggest the major sources, and clarify the major themes, of Renaissance theoretical discussions of generation. This is an attempt to look back at the major Greek medical writers not from the twentieth century but from the sixteenth.
Long-Haul Trucking

Advances in technology applied to tractor-trailers and the trucking infrastructure are delivering bottom line advantages and improved human factors. The U.S. long-haul trucking industry is a highly-competitive, multi-billion dollar industry which supports both national productivity and international trade. Within the industry, the intense competition results in cost and schedule pressures that push long-haul drivers to their limits resulting in physical and mental health problems and a life expectancy that is 23 years below that of the average American.
Supporting Educators to Implement Mand Training for a Student with Multiple Disabilities

The purposes of the study were to assess the effects of an online learning module on the implementation of mand training by a classroom team and determine whether training improved manding for a st...
Robotic Equipment and Instrumentation

The advancement of laparoscopic robotic surgery largely depends on the development of innovative laparoscopic instrumentation. The most widely used system, the da Vinci surgical robot (Intuitive Surgical Inc., Sunnyvale, California), was introduced in 1998 and received FDA approval in 2000. Its popularity may largely be attributed to the development of EndoWrist instruments with increased degrees of freedom and improved stereoscopic vision. The electronics integrated into the system allow motion scaling of surgeon hand movement into smaller instrument tip movements in the field, reducing natural tremor of surgeon’s hands. Instruments have a total of six degrees of freedom plus grip, mimicking the up and down and side-to-side flexibility of human wrist. Recently da Vinci S system has introduced (Intuitive Surgical Inc.), which features easier docking, added system feedback and high-definition telemonitoring. Another feature of the new S system is the additional 2 inches of length of the instruments.
Cognitive-Behavioral Therapy for Youth with Functional Somatic and Internalizing Symptoms

Functional somatic symptoms (FSS) are prevalent, highly comorbid with internalizing symptoms (e.g., anxiety and depression), and cause significant impairment to youth and their families. Children and adolescents with FSS typically pursue repeated medical consultations without relief, and internalizing symptoms are rarely detected. Research has shown that cognitive-behavioral therapy (CBT), an effective intervention for internalizing disorders, is a promising alternative treatment approach for youth with FSS. Physicians can play a critical role in facilitating patients’ access to CBT by identifying internalizing symptoms and promoting families’ engagement in a nonmedical intervention. This chapter provides guidelines to help physicians identify internalizing symptoms and provide psychoeducation about the biopsychosocial model. A description of brief cognitive-behavioral strategies that can be implemented by physicians and their staff, as well as more specialized techniques that should be implemented by a professional with training in CBT, will be presented. Finally, two case studies will illustrate the application of CBT for youth with FSS and internalizing symptoms.
Transplant uretero-inguinal hernia resulting in urosepsis.

Abstract Uretero-inguinal hernias are rare and can be difficult to diagnose. We present a case of a rare transplant kidney uretero-inguinal hernia. An 81-year-old male presented with urosepsis and was found to have an obstructed transplanted kidney secondary to herniation of the ureter into an inguinal hernia. The patient required interventional radiology decompression of the urinary system with a percutaneous nephrostomy tube. In this case, the patient's uretero-inguinal hernia was the extraperitoneal subtype allowing the diagnosis to be made easily on computed tomography imaging of the abdomen and pelvis which facilitated rapid treatment.
QTL Mapping Identifies Novel Source of Resistance to Fusarium Wilt Race 1 in Citrullus amarus.

Fusarium wilt race 1, caused by the soilborne fungus Fusarium oxysporum Schlechtend.: Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon), is a major disease of watermelon (Citrullus lanatus...
Abstract TMP80: Physician Preferences, Beliefs, and Practices on Post-Stroke Dysphagia Management

Introduction: Dysphagia affects up to 2/3 of stroke patients; however, management practices are widely disparate. Despite lack of evidence for percutaneous endoscopic gastrostomy (PEG) placement, P...
Cacao and Violence: Consequences of Money in Colonial Guatemala

This article investigates the meeting of two monetized economies and how producing a “commodity money” nurtured forms of violence. This case presents an opportunity to rethink why economies monetize and how that relation fits into coercive, violent foundations of an emerging capitalist system. Money is important for understanding early capitalism, as Marx suggested that money is the first form of the appearance of capital. Money masks the social nature of labor, a fiction that not only creates conditions for capitalism, but is violent by wrenching the self from social bonds. Archaeological examples illustrate relationships of money with corporeal and social violence in the Izalcos region of colonial Guatemala, part of today’s western El Salvador. The early colonial market relied on exploiting inequalities as well as the predictability of native production. A stable currency based on cacao as small coin buffered the awkwardness and unpredictability of a volatile economy.
Short-Term Voltage Stability of Power Systems with High Inverter Penetration under Small Disturbances

The penetration of inverter-based resources (IBR) has reached critically high levels in many power systems. There are growing concerns due to decreased mechanical inertia as well as voltage stability issues in such power systems. Commercial IBRs operate as grid-following (GFL) sources; they track and follow the voltage and frequency at the terminals of the inverter. These inverter controls rely on existing synchronous machines to provide a stiff voltage and frequency and do not actively contribute to supporting the system stability. In contrast, a grid-forming (GFM) inverter actively controls voltage and frequency at its inverter terminals, which can be help support the system during disturbances. In this work, the voltage stability of the IEEE 39 bus system with increasing inverter penetration is investigated for small disturbances. Simulations are performed with increasing penetration of both GFL and GFM inverters and the resulting waveforms are presented. Instabilities are observed with GFL control at higher penetration levels whereas GFM controls exhibited stable operation for small disturbances. GFL controls demonstrated increased sensitivity to nonlinear load models while GFM controls did not exhibit any such issues.
Is Narcissism a Slow Life History Strategy Indicator?: The Answer Depends on the LHS Instrument:

The dark triad (DT) traits are differentially related to psychometrically assessed life history strategy (LHS), such that psychopathy is strongly associated with a faster LHS, whereas narcissism appears to be, if anything, a slow LHS indicator. However, the research supporting these generalizations has been based largely on undergraduate samples in which LHS has been measured using the Arizona Life History Battery (ALHB; or its short version the Mini-K), an instrument that arguably lacks adequate coverage of low-extroversion content linked to a slower LHS. In this study, 929 U.S. MTurk workers completed a set of DT instruments, a 10-item Big Five Inventory, a 42-item version of the ALHB (K-SF-42), and the life history rating form (LHRF), which is less weighted toward high extroversion content than the ALHB. Factor analysis of the DT instruments yielded factors corresponding to callousness, secondary psychopathy, and socially adaptive narcissism (leadership/authority and grandiose exhibitionism). Callousness and secondary psychopathy were fast LHS indicators with respect to both LHS instruments. Socially adaptive narcissism appeared as a slow LHS indicator with respect to the K-SF-42 but as a fast LHS indicator with respect to the LHRF. Variation in extroversion accounted entirely for the K-SF-42's positive association with socially adaptive narcissism. This study suggests that narcissism's apparent status as a slow LHS indicator may be more a matter of measurement than of substance.
Combining Modern and Paleoceanographic Perspectives on Ocean Heat Uptake.

Monitoring Earth's energy imbalance requires monitoring changes in the heat content of the ocean. Recent observational estimates indicate that ocean heat uptake is accelerating in the twenty-first ...
On the Importance of Pigou's Mathematical Model in Part II of His 1933 The Theory of Unemployment to the Development of Keynes's IS-LP(LM) Model in the General Theory: Keynes Had No Mathematical Model Supporting His Y=C plus I Model Until He Integrated an Improved Version of Pigou's Model into the D-Z Model of Chapter 20 of the General Theory

Keynes created, developed, taught and applied his version of the IS-LM model,which he called the IS-LP model, between Dec. 1933 and February,1936 when the General Theory appeared in print. However, before Pigou’s July,1933 book came out, Keynes had no worked out D-Z model to support the derivation of his Y=C I model that lay at the heart of his IS-LP(LM) model. Keynes needed to support the Y model, introduced on page 63 of the General Theory along with the IS condition and analyzed more explicitly in chapter 10 of the General Theory, with an explicit microeconomic foundation in the theory of the firm, production function, labor market, incorporation of profit and price expectations, and marginal analysis. Pigou’s 1933 The Theory of Unemployment showed Keynes exactly what to do and how to proceed. Keynes’s D-Z model is an improved version of Pigou’s model in chapters 8-10 of Part II of Pigou’s book, as acknowledged by Keynes in his appendix to chapter 19 of the general Theory and to H. Townshend in correspondence. Keynes’s introductory, original IS-LP(LM), presented on December 4,1933 at his student lectures and published in the 1934 draft of the General Theory, incorporated a Y variable at the macroeconomic level that had no corresponding microeconomic foundations or incorporation of price and profit expectations.Keynes’s final presentation of his IS-LP(LM) model in chapter 21 rests on a technical elasticity analysis that is based on the D-Z analysis of chapter 20,which is the chapter where Keynes developed his Pigou–like “concoctions” that he had alluded to in the appendix to chapter 19 and in his correspondence with Townshend into the mathematical foundations for the General Theory. Keynes was stuck in late 1933 with an IS-LP(LM) model without any micro foundations. Exactly the same issue had occurred in his 1930 A Treatise on Money. Keynes adapted Pigou’s mathematical analysis and modeling techniques,presented in his 1933 The Theory of Unemployment, to provide him with the needed tools so that he could provide his main General Theory model, ther IS-LP(LM) model, with exactly the precise mathematical foundation in microtheory he needed to finish writing the General Theory. The conclusion reached is that Keynes could not have finished writing the General Theory by 1936 if Pigou had not published his 1933 The Theory of Unemployment in July,1933 first. Pigou never at any point in his lifetime sought to point out in print that Keynes’s chapters 20 and 21 analysis,as well as the analysis presented in footnote two on pages 55-56 of the General Theory, were very similar to his own original presentation of a macro model in July, 1933.
Approximate Representations of Shaped Pulses Using the Homotopy Analysis Method.

Abstract. The evolution of nuclear spin magnetization during a radiofrequency pulse in the absence of relaxation or coupling interactions can be described by three Euler angles. The Euler angles, in turn, can be obtained from the solution of a Riccati differential equation; however, analytic solutions exist only for rectangular and hyperbolic-secant pulses. The homotopy analysis method is used to obtain new approximate solutions to the Riccati equation for shaped radiofrequency pulses in nuclear magnetic resonance (NMR) spectroscopy. The results of even relatively low orders of approximation are highly accurate and can be calculated very efficiently. The results are extended in a second application of the homotopy analysis method to represent relaxation as a perturbation of the magnetization trajectory calculated in the absence of relaxation. The homotopy analysis method is powerful and flexible and is likely to have other applications in magnetic resonance.
Stochastic simulation algorithms for Interacting Particle Systems

Interacting Particle Systems (IPSs) are used to model spatio-temporal stochastic systems in many disparate areas of science. We design an algorithmic framework that reduces IPS simulation to simulation of well-mixed Chemical Reaction Networks (CRNs). This framework minimizes the number of associated reaction channels and decouples the computational cost of the simulations from the size of the lattice. Decoupling allows our software to make use of a wide class of techniques typically reserved for well-mixed CRNs. We implement the direct stochastic simulation algorithm in the open source programming language Julia. We also apply our algorithms to several complex spatial stochastic phenomena. including a rock-paper-scissors game, cancer growth in response to immunotherapy, and lipid oxidation dynamics. Our approach aids in standardizing mathematical models and in generating hypotheses based on concrete mechanistic behavior across a wide range of observed spatial phenomena.
Stabilization of polyacrylonitrile fibers with carbon nanotubes

Abstract Stabilization is an energy-intensive and time-consuming step for making PAN-based carbon fiber. Here, a new pathway is shown that uses carbon nanotubes (CNT) to accelerate the reaction rate and to reduce the PAN stabilization time. Bi-component core-sheath PAN-PAN/CNT (10 wt% CNT) fibers and single-component PAN/CNT (10 wt% CNT) fibers were made. When comparing to PAN fiber with comparable diameter, the heat of stabilization ( Δ H r e a c t i o n ) of PAN/CNT fibers increased up to 3 times in the air, while it did not change in N2. The addition of CNTs reduced the activation energy ( E a ) of PAN cyclization by up to 12% but increased it for the oxidation reaction by up to 80% compared to PAN fibers. CNTs did not increase the kinetic constant of the cyclization reaction but increased it for the oxidation reaction (koxidation) by up to 5 times, when comparing to PAN fiber at 250°C. At the same temperature, the bi-component PAN/CNT fiber bundle was fully stabilized in less than 2 hours, while the PAN fibers with comparable diameter took 6 hours to stabilize. Porosity was observed in the PAN/CNT precursor as well as in the stabilized PAN/CNT. This porosity was considered, at least partially responsible for increased oxygen diffusion, and hence for the decrease in the PAN stabilization time.
Extracting Fractional Inspiratory Time from Electrocardiograms.

Non-invasive at-home monitoring of lung and lung airways health enables the early detection and tracking of respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD). Various proposed approaches estimate the respiratory rate and extract the respiratory waveform from an electrocardiogram (ECG) signal as a way to discreetly monitor lung health. Unfortunately, these approaches fail to accurately capture the respiratory cycle phase features, resulting in a non-specific, incomplete picture of lung health. This paper introduces an algorithm to extract more respiratory information from the ECG signal by framing the problem as a binary segmentation task. In addition to respiratory rate (RR), the algorithm derives the fractional inspiratory time (FIT), a direct measure of airway obstruction derived from respiratory phase information. The algorithm is based on a gated recurrent neural network that infers vital respiratory information from a single-lead ECG signal. We measure our algorithm's performance on 5 subjects from the MIMIC dataset and 5 subjects from the CEBS database. Our algorithm maintains exceptional performance in estimating the respiratory rate and outperforms current algorithms that extract the respiratory cycle phases and FIT/ inspiratory:expiratory ratio (IER). Our algorithm reports a root mean squared error (RMSE) of 0.06 in the computation of FIT (values range from 0.2-0.6) and a RMSE of 0.54 breaths per minute (bpm) for respiratory rate (values range from 8 - 28 breaths per minute (bpm)) on the MIMIC dataset, and an FIT RMSE of 0.11 and and RR RMSE of 0.66 bpm on the CEBS dataset.
Evidence of regional specializations in regenerated zebrafish retina

Abstract Adult zebrafish are capable of functional retinal regeneration following damage. A goal of vision science is to stimulate or permit a similar process in mammals to treat human retinal disease and trauma. Ideally such a process would reconstitute the stereotyped, two-dimensional topographic patterns and regional specializations of specific cell types, functionally important for representation of the visual field. An example in humans is the cone-rich fovea, essential for high-acuity color vision. Stereotyped, global topographic patterns of specific retinal cell types are also found in zebrafish, particularly for cone types expressing the tandemly-replicated lws (long wavelength-sensitive) and rh2 (middle wavelength-sensitive) opsins. Here we examine whether regionally specialized patterns of LWS1 and LWS2 cones are restored in regenerated retinas in zebrafish. Adult transgenic zebrafish carrying fluorescent reporters for lws1 and lws2 were subjected to retinal lesions that destroy all neurons but spare glia, via intraocular injection of the neurotoxin ouabain. Regenerated and contralateral control retinas were mounted whole or sectioned, and imaged. Overall spatial patterns of lws1 vs. lws2 opsin-expressing cones in regenerated retinas were remarkably similar to those of control retinas, with LWS1 cones in ventral/peripheral regions, and LWS2 cones in dorsal/central regions. However, LWS2 cones occupied a smaller fraction of regenerated retina, and several cones co-expressed the lws1 and lws2 reporters in regenerated retinas. Local patterns of regenerated LWS1 cones showed modest reductions in regularity. These results suggest that some of the regional patterning information, or the source of such signals, for LWS cone subtypes may be retained by undamaged cell types (Muller glia or RPE) and re-deployed during regeneration.
Suspicious and fraudulent online survey participation: Introducing the REAL framework:

Online survey research has significantly increased in popularity in recent years. With its use, researchers have a new set of concerns about data collection and analysis to consider, including the ...
Abstract 19084: Novel Method Using Intracardiac Myocardial Elastography Provides Real-time Assessment of Right and Left Atrial Radiofrequency Ablation Lesions in Humans

Introduction: Radiofrequency (RF) ablation is an effective method for treatment of cardiac arrhythmias; however, current assessment of RF lesion formation by measuring impedance changes, electrogram dimunition, power and catheter temperature are indirect and may be inaccurate. We present a novel, imaging modality, myocardial elastography (ME), which when used in adjunct with intracardiac echocardiography (ICE) may provide real-time assessment of RF lesion formation, and changes in tissue mechanics after lesion delivery. Methods: 7 patients (mean age 64.3 +/- 14 years) underwent imaging of their left atrium with a 5.8-MHz ICE probe before and after RF ablation with an irrigated catheter at high frame rates (1200 Hz). The channel data was acquired on a clinical ultrasound system, image reconstruction and motion tracking were performed, and cumulative axial strains were obtained from displacement estimations. The location of the ablation lesion was confirmed using ICE imaging, electroanatomic mapping and flu...
Recent Developments and Applications of the SEC-vidicon for Astronomy

Publisher Summary This chapter elaborates the developments and applications of the secondary electron conduction (SEC)-vidicon for astronomy. The engineering development of the SEC-vidicon as an astronomical sensor has continued at Princeton University Observatory in parallel with its operational use. The developmental effort includes the enhancement of the basic attributes that make the SEC-vidicon an appropriate sensor—namely, high quantum efficiency, low threshold, long integration time, and also work to broaden its scientific usefulness, such as, the development of a magnesium fluoride photocathode window for vacuum-ultraviolet sensitivity, and a permanent-magnet focus assembly for thermal compatibility, with proposed large space-telescopes. The entire tube including the image section is magnetically focused by immersion in an 80-G axial magnetic field. The use of a magnetically focused image section is required to maintain high modulation transfer function over the image format and to have the plane photocathode. It is found that the photocathode dark current and other background emissions within the image section are strongly influenced by temperature.
Cell lineage of zebrafish blastomeres: III. Clonal analyses of the blastula and gastrula stages

Aspects of the early lineages of blastomeres in the embryo of the zebrafish, Brachydanio rerio have been described. Because of the optical clarity of the embryo, lineages of selected cells can be followed directly by microscopy through many cell divisions. Also, it is shown here that the fluorescent molecules fluorescein-dextran and rhodamine-horseradish peroxidase can be used as cell lineage tracers, marking the clonal progeny of founding blastomeres. The labeled cells can be easily visualized in the live embryo, and utilizing a sensitive video camera to amplify fluorescence, the same clone may be examined repeatedly while the cells divide and migrate. Cells that descend from a single blastomere remain closely associated together through the end of the blastula stage. At the time when epiboly begins (early gastrula) cells in the labeled clone scatter and become dispersed among unlabeled cells. It has been observed that there is no invariant mapping of the embryo's midline (determined by the position of the embryonic shield in the gastrula) with respect to the early planes of cleavage. This finding shows that in the zebrafish the region of the embryo that a cell will occupy is not specified by the cell's early ancestory.
Evaluation of Environmental Degradation Kinetics Using Hierarchical Bayesian Modeling

AbstractThis paper introduces the use of hierarchical Bayesian modeling as a method to estimate how kinetic properties of environmental contaminants vary across experimental factors. The hierarchical modeling framework utilizes a multilevel statistical structure, in which kinetic rate constants represent contaminant degradation behavior for individual, lower-level experiments, but also exhibit a higher-level structure across different experimental conditions. The main benefit of this modeling approach is the ability to pool information between experiments in order to reduce the influence of outliers and produce more robust predictions of degradation rate constants in an out-of-sample context. The Bayesian estimation method is also very flexible, with the ability to relax distributional assumptions on parameters, account for heteroscedasticity in model residuals, include prior information or expert knowledge when available, and propagate all uncertainties into model predictions, all with relative ease. The...
Teachers' Perspectives on Factors that Affect Computer Use

AbstractThis article reports results of a study that focused on computers and teachers’ work. K–12 teachers were surveyed about their current computer use for noninstructional activities and about their perspectives on facilitating and impeding factors. The highest percentage of subjects used computers for preparing instructional materials (94.4%); the second most popular use was looking for information in a particular subject area (58.3%). Multiple linear regressions analyzed the collective predictiveness of organizational factors (time, training, technology-related support, access to computers, and collaboration) and individual characteristics (gender, age, experience, self-perception of computer expertise, and source of computer learning) on frequency of use for each activity. Of 14 tasks, 11 had at least one significant predictor, and 7 of these bad more than one predictor.
A new discrete-time state model for linear dynamical systems with continuously-varying control/disturbance inputs

A new form of discrete-time state model for linear dynamical systems is derived. Unlike conventional discrete-time models, this new model accommodates cases where the values of the system inputs (controls u(t) and/or disturbances w(t)) may vary continuously with time (in an uncertain manner) over each sample-interval kT/spl les/t >
CONTROL OF MOTOR-UNIT TENSION BY RATE MODULATION DURING SUSTAINED CONTRACTIONS IN REINNERVATED CAT MUSCLE

1. The aim of this study was to describe the control of tension by rate modulation of single motor units in reinnervated muscle. 2. Single fast-twitch motor units were isolated from medial gastrocnemius (MG) muscles in two groups of anesthetized adult cats: one in which the MG nerve was left untreated and another in which that nerve was sectioned and immediately sutured together 10-33 mo before study. Together with conventional measures of isometric contractile properties, units were tested with the use of computer-controlled feedback regulation of stimulation rate to maintain tension during continuous isometric contraction at a constant submaximal level [25% of maximal tension (Pmax)]. 3. For motor units from both groups, stimulation rate began to decline after target tension was attained and then settled at lower values for variable durations before rapidly increasing, usually within the last 5% of the contraction's duration, until reaching the experimentally selected limit of 100 pulses/s (pps). 4. Measures of the declining phase in stimulation rate occurring at the beginning of sustained contraction were not significantly different in comparison of untreated versus reinnervated muscles. These measures included 1) the magnitude of the decrease in rate, 2) the minimum rate attained, and 3) the time taken to reach minimum stimulation rate expressed as a fraction of endurance time (Et, total duration of the sustained contraction). 5. Most fast-twitch units from reinnervated muscles fell within normal limits for both endurance time and the number of stimuli applied over that period.(ABSTRACT TRUNCATED AT 250 WORDS)
Receptor-Misrouting: An Unexpectedly Prevalent and Rescuable Etiology in Gonadotropin-Releasing Hormone Receptor-Mediated Hypogonadotropic Hypogonadism

Fourteen mutations (13 missense and 1 truncation) of the GnRH receptor (GnRHR) have been identified in patients with hypogonadotropic hypogonadism (HH). We have previously shown that five of the missense mutations can be rescued with a GnRH peptidomimetic antagonist that acts as folding template, stabilizing (otherwise) misfolded GnRHR mutants and thereby restoring function. We now report that this approach rescues 11 of 13 of these GnRHR missense mutants. These data indicate the surprisingly general nature of this approach, an observation that presents therapeutic opportunities for HH and other disorders resulting from protein misfolding. A classification system for GnRHR mutants is proposed.
Trends and Precedents Favoring a Regulatory Embrace of Smart Radio Technologies

Burgeoning demands for communications bandwidth stress the abilities of military and civil spectrum managers to provide needed access to spectrum resources while taking appropriate measures to avoid causing harmful interference to legacy users. Empirical analysis shows that radio frequency (RF) bandwidth is often available: measurement data indicate that while most channels are used at some times, most channels remain unused at any given time. Going forward, so- called "smart radio" technologies will be able to exploit these holes in the RF spectrum and will play a crucial role in achieving the core objectives of efficient spectrum management. The United States Defense Advanced Research Projects Agency's ("DARPA") next generation communications program ("XG") is on the vanguard of smart radio innovations. In particular, XG technology uses automated intelligence at a system's edges in order to navigate real-time fluctuations in spectral conditions that cannot be precisely predicted in advance. This dynamism will enable opportunistic use of intermittently available spectrum. This paper examines how the introduction of smart radio technologies fit within past precedents and current regulatory developments involving shared use of spectrum resources. The key finding is that implementation of smart radios in the near term would represent an incremental policy step that is consistent with policy trends and recent regulatory actions. Two perspectives militate in favor of this conclusion. First, smart radio systems enable regulators and spectrum managers to more efficiently achieve long-held policy and spectrum management objectives. And second, the regulatory prospects of smart radios are further buoyed by contemporary examples of approved technologies and sharing methods that are modest precursors to XG. Case studies are used to underscore that while smart radios promote vast gains in spectrum accessibility and interference avoidance, implementation of smart radio systems follows a lengthening line of precedents promoting flexibility and collaborative sharing techniques. Accordingly, in the face of sharp increases in demand from a wide assortment of spectrum users, it is clear that regulators and spectrum managers will - and, indeed, should - embrace smart radio systems as a tool to help resolve the spectrum access challenges of today and tomorrow.
Protection from chlordecone (kepone®-potentiated CC14 hepatotoxicity in rats by fructose 1,6-diphosphate

Abstract 1. 1. The extent of liver injury assessed as elevation of plasma transaminases was decreased 40–50% by administration of fructose 1,6-diphosphate to rats receiving the highly hepatotoxic combination of chlordecone and CCl 4 . 2. 2. This protection was accompanied by significantly higher sustenance of ATP levels in the liver. 3. 3. Polyamine synthesis as well as interconversion were stimulated in favor of maintaining higher levels of polyamines. 4. 4. These events are consistent with the concept that suppressed hepatocellular regeneration which leads to progression of otherwise limited injury observed in chlordecone potentiation of CCl 4 hepatotoxicity is due to lack of cellular energy.
Dorsoventral patterning of the avian mesencephalon/metencephalon: role of the notochord and floor plate in suppressing Engrailed-2.

Transcription factors that are spatially and temporally restricted within the embryo may be used for dorsoventral and rostrocaudal positional information during development. The Engrailed-2 (En-2) gene is expressed across the mesencephalon/metencephalon (mes/met) boundary in the cerebellar primordium with strong dorsolateral expression and limited expression in the floor plate. In a previous experiment we demonstrated that, after removal of Hensen's node, embryos lacked a notochord in the head and the pattern of En-2 expression was normal rostrocaudally, but it was expanded into the ventral midline of the neural tube. This suggested that the notochord suppresses En-2 in the ventral neural tube during normal development. To test further the ability of the notochord (and floor plate) to suppress En-2, we transplanted ventral midline tissues from HH 5–9 quail embryos beneath the rostral neural plate of HH 4–6 chick embryos. After 24 hours in culture, 90% of the embryos with quail notochord or floor plate near the mes/met of the host lacked En-2 expression adjacent to the graft, and suppression was distance dependent. Enzymatically isolated notochords also suppressed En-2 (71%), but the results from isolated floor plates were inconclusive. Other grafts served as controls and included tissues from the trunk ventral midline, mes/met level dorsolateral neural plate, and trunk dorsolateral neural plate/somite. Collectively, the results suggest that during normal development the notochord and possibly the floor plate are important regulators of normal En-2 expression. © 1995 John Wiley & Sons, Inc.
Predictive Compact Modeling for Strain Effects in Nanoscale Transistors

As the gate length (Lg) of a MOSFET is scaled down and carrier transport is enhanced increasingly via process-induced strain, the transistor drive current becomes limited by the carrier injection velocity from the source into the channel [1]. Hence, the quasi-ballistic transport model proposed by Lundstrom et al. [2] is more suitable for predicting nanoscale MOSFET behavior. By self-consistently solving for the charge density at the top of the potential barrier and the surface Fermi level, it is straightforward to calculate the transistor current:
Characterization of gene expression in recombinant Escherichia coli cells infected with phage lambda

Phage lambda infection was investigated for possible production of toxic foreign proteins in Escherichia coli. The target gene transcription was regulated by a T7 promoter, which was initiated under the action of T7 RNA polymerase delivered by infecting phage. Two types of phage infection were investigated. In both cases, deletion of the int gene prevents lysogenic integration. One phage, lambda CE6, contains the Sam7 lysis mutation, so that infectious phage particles remain intracellular. The other phage, lambda CE6M, undergoes the complete lytic pathway so that the infected cell is eventually lysed. The dynamics of phage adsorption, foreign protein synthesis, and cell growth were analyzed as a function of various parameters, such as MOI (multiplicity of infection), cell concentration at infection, culture temperature, and different carbon sources. A low basal level of the foreign protein, beta-galactosidase, was obtained prior to infection, whereas it reached about 0.1 g/L after phage "induction" under appropriate infection conditions. Due to low basal expression, this expression system is useful for the production of toxic foreign proteins.
Solar heating of suspended particles and the dynamics of Martian dust devils

The heat input to Martian dust devils due to solar warming of suspended particles is assessed based on a prior estimate of dust loading and from an analysis of shadows cast by dust devils in images taken from orbit. Estimated values for solar heating range from 0.12 to 0.57 W/m3 with associated temperature increases of 0.011 to 0.051(deg)C per second. These warming rates are comparable to the adiabatic cooling rate expected for a gas parcel rising on Mars with a vertical velocity of 10 m/s. Solar warming of suspended dust serves to maintain buoyancy in a rising dust plume and may be one cause for the large scale of dust devils observed on Mars.
Robustness of mount systems for idle NVH, Part II: pendulum mounts

The pendulum mounting strategy in east-west powerplant configurations is based on two major mounts, one at the engine side and the other at the transmission side and one or two roll-restrictors. This system is used in many of today's vehicles, particularly those with lighter powertrains. This paper discusses the variability of the modal decoupling strategy as a function of variations of the powertrain pendulum mount stiffness, location and inertia properties. In addition, this paper discusses impact of mass and inertia variations. A six degrees of freedom model is used in the analysis. Detailed design of experiment studies are described.
Register-insertion: a protocol for the next generation of ring local-area networks

Abstract The register-insertion ring is known for its high maximum throughput as well as its low average response time at medium and high loads. We develop a new analysis for the average response time of the register-insertion ring. The average waiting time (which is the most important component of the average response time estimate) is computed using a new queueing model. Also given is a partitioning scheme that can reduce the average response time by half and increase the maximum throughput by at least 60% of the media transmission rate. The partitioning scheme is analyzed, simulated, and compared with the performance of the regular register-insertion ring. Furthermore, the average response time of the register-insertion ring is compared with the lower bounds of the average response time for the token-passing and slotted rings. In particular, we derive an approximate formula for the throughput at which a register-insertion ring performs better than any token-passing ring. The formula shows that with a long average packet length the register-insertion ring can have a better average response time even at low loads.
Doctor's Order: An Early Modern Doctor's Alchemical Notebooks

This is a case study on a series of at least thirty-four sixteenth-century notebooks from the Sloane collection, which reconsiders early modern note taking techniques and the organisation of knowledge. These notebooks were written by an anonymous compiler, a physician who read widely in the alchemical and medical literature available in his lifetime, the late sixteenth century. In the alchemica, he devotes individual volumes to specific alchemical substances, which are connected with each other by means of a complex system of cross-referencing; they are constantly revised and change appearance according to the physician's latest ideas about alchemical medicines. As a result, the notebooks not only preserve received information (a task otherwise performed by commonplace books in this period)— they also represent an equivalent to the alchemical workshop, where the combination of different textual elements generates knowledge.
On the radius of analyticity of solutions to the three-dimensional Euler equations

We address the problem of analyticity of smooth solutions u of the incompressible Euler equations. If the initial datum is real-analytic, the solution remains real-analytic as long as f t 0 ∥∇u(·, s)∥ L∞ ds < ∞. Using a Gevrey-class approach we obtain lower bounds on the radius of space analyticity which depend algebraically on exp ∫ t 0 ∥∇u(·,s)∥ L∞ ds. In particular, we answer in the positive a question posed by Levermore and Oliver.