cssi/SciSciGPT-SciSciNet huggingface dataset:
Mouse Models to Study Dengue Virus Immunology and Pathogenesis

The development of a compelling murine model of dengue virus (DENV) infection has been challenging, because dengue virus clinical isolates do not readily replicate or cause pathology in immunocompetent mice. However, research using immunocompromised mice and/or mouse-adapted viruses allows to investigate questions that may be impossible to address in human studies. In this review, we discuss the potential strengths and limitations of existing mouse models of dengue disease. Human studies are descriptive by nature; moreover, the strain, time, and sequence of infection are often unknown. In contrast, in mice, the conditions of infection are well defined and a large number of experimental parameters can be varied at will. Therefore, mouse models offer an opportunity to experimentally test hypotheses that are based on epidemiological observations. In particular, gain-of-function or loss-of-function models can be established to assess how different components of the immune system (either alone or in combination) contribute to protection or pathogenesis during secondary infections or after vaccination. In addition, mouse models have been used for pre-clinical testing of antiviral drug or for vaccine development studies. Conclusions based on mouse experiments must be extrapolated to DENV infection in humans with caution due to the inherent limitations of animal models. However, research in mouse models is a useful complement to in vitro and epidemiological data, and may delineate new areas that deserve attention during future human studies.
Broadband optical pulse scattering from a glass fiber

We report results of scattering measurements using femtosecond pulses to collect a wealth of information in a single experiment. Potential issues with particle scattering, such as variation in particle size, were avoided by using 9 and 50 μm diameter glass fibers. We first establish an angular scattering intensity baseline, and we show that the spectral width of very short pulses leads to smoothing of the angular scattering pattern, consistent with continuous broadband illumination. We then measure the angular scattering pattern from short pulses with a spectrometer and reveal an underlying spectral periodicity of broadband scattered light that is consistent with narrowband cw scattering. Our experimental results compare well with existing theory. We show that such two-dimensional experimental data and derived analytic solution can provide robust characterization of scattering objects even in the presence of noise.
Comparisons of improved bonferroni and sidak/slepian bounds with applications to normal markov processes

The recent literature contains theorems improving on both the standard Bonferroni inequality (Hoover (1990)) and the Sidak/Slepian inequalities (Glaz and Johnson (1984)), The application of these improved theorems to upper bounds for non coverage of simultaneous confidence intervals on multivariate normal variables is explored. The improved Bonferroni upper bounds always hold, while improved Sidak/Slepian bounds only apply to special cases. It is shown that improved Sidak/Slepian bounds will always hold for Normal Markov Processes, a commonly occuring and easily identifiable class of multivariate normal variables. The improved Sidak/Slepian upper bound, if it applies, is proven to be superior to the computationally equivalent improved Bonferroni bound. This improvement, however, is not great when both methods are used to determine upper bounds for Type I error in the range of .01 to .10.
Staring phased-array radar using photorefractive crystals

We describe a photorefractive phased array radar processor which directs its look angle to the signal of interest and puts nulls in the array function at the locations of jammers. We derive the array null depth using a simple model of the photorefractive response which includes photorefractive erasure. We analyze the response time of the system, showing that it is independent of the photorefractive time constant. Finally we analyze the response of the system to multiple simultaneous jammers, and to irregular wave fronts establishing that the array response organizes itself to conform to non-planar incident waves. This last property allows the system to be used in complex radar environments and on large irregular nonrigid radar arrays.
Unsettling Recolonization: Labourism, Keynesianism and Australasia From the 1890s to tHe 1950S

This paper addresses the now entrenched historiography of the Australian Settlement and New Zealand variations thereof. Against the central premise of this historiography, that a particular regime of domestic insulation and external orientation to the British market constrained development and persisted unchanged until the neo-liberal restructuring of the 1980s, it is argued here that the political economy of the beginning of the 20th century was profoundly destabilized by the Depression. As a result, a new, Keynesian regime was established in New Zealand from the late 1930s and in Australia a few years later. The entrenchment of this regime depended upon adoption by remade conservative parties by the end of the 1940s.
An evidence-based review of endoscopic frontal sinus surgery.

BACKGROUND: Endoscopic approaches to treat frontal sinus disease gained in popularity over the past 20 years with a plethora of published studies that emphasize the high success rate of such surgeries. This study was designed to determine the levels of clinical evidence in the otolaryngology literature that address the efficacy of endoscopic approaches in the management of frontal sinus disease including frontal sinusitis. METHODS: Twenty-three publications that reported the surgical outcomes of endoscopic approaches to treat frontal sinus disease were reviewed. Data were collected regarding the study design, operative technique, number of patients, duration of follow-up, diagnostic method, surgical success rate, and method(s) used to assess surgical outcome. RESULTS: The study designs were a retrospective case series without control (16 articles), prospective case series without control (3 articles), and retrospective case series with internal control (4 articles). Eighty-three percent of the published articles provide an evidence level of IV, while the remaining 17% provide an evidence level of III. The surgical technique was described as frontal sinusotomy (n = 4), frontal sinusotomy or frontal sinus drillout (n = 1), frontal sinus drillout alone (n = 1), endoscopic modified Lothrop procedure (n = 9), Draf types I, II, or III (n = 6); trans-septal frontal sinusotomy (n = 1); and frontal sinus rescue procedure (n = 1). The mean number of subjects was 44, and the average follow-up period was 23.6 months. Surgical success rate ranged from 50 to 100%. CONCLUSION: Despite the number of reports in the literature that address the surgical outcome of endoscopic approaches for treatment of frontal sinus disease, the majority of these studies have a small population size, short follow-up period, and provide a low clinical evidence level.
Carnivalesque Freedom in Hawthorne's Young Goodman Brown

(2007). Carnivalesque Freedom in Hawthorne's Young Goodman Brown. The Explicator: Vol. 65, No. 3, pp. 143-145.
Experimental calibration of a numerical model describing the alteration of cement/caprock interfaces by carbonated brine

Deep wells provide a possible pathway for CO2 and brine leakage from geologic storage reservoirs to shallow groundwater resources and the atmosphere. The integrity of wellbore cement in these environments is of particular concern, because it is not known if changes in cement properties resulting from reaction with CO2-rich brines will lead to enhanced leakage over the life cycle of the storage reservoir. Assessment of wellbore leakage will ultimately be answered through models that capture both the chemical and physical processes and the uncertainty of key parameters within the wellbore environment. Towards this end, we use the results for 13 core–flood experiments conducted at variable partial pressures of CO2, flow rate, durations, and cement–caprock apertures to constrain a wellbore model that couples chemical processes important to assessing the long-term integrity of wellbore cements in geologic carbon storage environments. X-ray computed microtomography collected prior-to and following the experiments was employed to spatially resolve the interface and the extent of the reaction zones, and time dependent solution chemistry was used to track the chemical alteration over the course of the experiments. In this manuscript we focus on the development of geochemical model that describes the alteration of both the cement and the caprock. In our experiments, chemical alteration of the cement significantly exceeded any dissolution of carbonate minerals within the caprock and fracture geometry played no role on the extent of reaction. The experimental data was used to calibrate a numerical model of wellbore-caprock interfaces coupling reaction-front chemistry, fluid flow and transport of dissolved species. The geochemical model adopts an idealized representation of the cement chemistry in which appropriate equilibrium conditions are enforced at a series of discrete reaction fronts. The equilibrium conditions are coupled by diffusive transport between the fronts, which also determines the rate of front propagation. Despite its simplicity, the calibrated model accurately reproduces the reaction-zone growth and effluent chemistry for the range of experimental conditions considered and allowed key parameters to be confirmed or calibrated. These include the use of portlandite, calcite, and analcime solubility as equilibrium controls at specific reaction fronts within the cement; the use of constant effective diffusivity for each alteration zone; and diffusive growth of the alteration layers.
Detection and Mechanistic Studies of Multicomponent Assembly by Fluorescence Resonance Energy Transfer

The kinetics and thermodynamics of multicomponent assembly in organic solution are investigated using fluorescence resonance energy transfer (FRET). Calix[4]arenes functionalized with ureas on thei...
Are we training our fellows adequately in delivering bad news to patients? A survey of hematology/oncology program directors

Abstract Background: Medical oncologists often must deliver bad news. The authors were interested in the extent of formal training in delivering bad news in hematology/oncology fellowships in the United States. Methods: An e-mail survey was sent to all hematology/oncology fellowship program directors in the United States. Surveys were e-mailed to 124 program directors and responses were received either via e-mail or regular mail. Program directors were asked the adequacy, the perceived necessity, the quality of this training, and the institutional support provided. It was also intended to elicit responses about the degree of formal training fellows receive in delivering bad news. χ2 Statistics were used to perform comparisons between items; p values of less than 0.05 were considered statistically significant. Results: Sixty-five surveys were completed and returned (52% response rate). The majority of programs, 82%, are in urban areas and 97% of the primary teaching hospitals are considered tertiary care c...
Thermodynamic consequences of an abasic lesion in duplex DNA are strongly dependent on base sequence.

The abasic site in DNA may arise spontaneously, as a result of nucleotide base damage, or as an intermediate in glycosylase-mediated DNA-repair pathways. It is the most common damage found in DNA. We have examined the consequences of this lesion and its sequence context on DNA duplex structure, as well as the thermal and thermodynamic stability of the duplex, including the energetic origins of that stability. To this end, we incorporated a tetrahydrofuran abasic site analogue into a family of 13-mer DNA duplexes, wherein the base opposite the lesion (A, C, G, or T) and the base pairs neighboring the lesion (C.G or G.C) were systematically varied and characterized by a combination of spectroscopic and calorimetric techniques. The resulting data allowed us to reach the following conclusions: (i) the presence of the lesion in all sequence contexts studied does not alter the global B-form conformation characteristic of the parent undamaged duplex; (ii) the presence of the lesion induces a significant enthalpic destabilization of the duplex, with the magnitude of this effect being dependent on the sequence context; (iii) the thermodynamic impact of the lesion is dominated by the identity of the neighboring base pairs, with the cross strand partner base exerting only a secondary thermodynamic effect on duplex properties. In the aggregate, our data reveal that even in the absence of lesion-induced alterations in global structure, the abasic lesion can significantly alter the thermodynamic properties of the host duplex, with the magnitude of this impact being strongly dependent on sequence context.
Growth and Succession in Suburban Communities

Previous studies of the growth of metropolitan communities, drawing primarily on ecological theory as represented by Burgess' concentric zone model of the metropolis, have highlighted the effects o...
Regulatory T cell kinetics in the peripheral blood of patients with Crohn's disease.

Estimates of T regulatory cell populations in the periphery of patients with Crohn’s disease are confounded by disease activity and concomitant immunotherapeutic agents known to affect T cell proliferation and survival. We performed deuterium pulse/chase experiments in patients with quiescent Crohn’s disease on no immunotherapy and healthy control subjects to estimate T regulatory cell kinetics. Quantification of deuterated DNA isolated from T cell subsets over 10 days was determined by mass spectrophotometry. We demonstrate enhanced proliferation within the T regulatory cell population from patients with Crohn’s disease when compared to non-T regulatory cells and T regulatory cells from healthy control subjects. We speculate that T regulatory cells isolated from the periphery of patients with Crohn’s disease experience persistent antigen stimulation resulting in excess proliferative rates.
Development of natural growth regimes for hatchery-reared steelhead to reduce residualism, fitness loss, and negative ecological interactions

Wild steelhead (Oncorhynchus mykiss) typically spend two or more years in freshwater before migrating to sea, but hatchery steelhead are almost ubiquitously released as yearlings. Their large size at release coupled with life history pathways that include both male and female maturation in freshwater present ecological risks different from those posed by hatchery populations of Pacific salmon. Yearling hatchery reared steelhead that fail to attain minimum thresholds for smoltification or exceed thresholds for male maturation tend to ‘residualize’ (i.e., remain in freshwater). Residuals pose ecological risks including size-biased interference competition and predation on juvenile salmon and trout. Three hatchery populations of steelhead in Hood Canal, WA were reared under growth regimes designed to produce a more natural age at smoltification (age-2) to aid in rebuilding their respective natural populations. Mean smolt sizes and size variability at age-2 were within the range of wild smolts for two of the three populations. The third population reared at a different facility under similar temperatures exhibited high growth rate variability and high male maturation rates (20% of all released fish). Experimentally comparing age-1 and age-2 smolt programs will help identify optimal rearing strategies to reduce the genetic risk of domestication selection and reduce residualism rates and associated negative ecological effects on natural populations. Investigations of Winthrop National Fish Hatchery summer-run steelhead will measure a) selection on correlated behavioral traits (‘behavioral syndromes’), b) degree of smoltification, c) changes in hormones that regulate gonad growth at key developmental stages, and d) conduct extensive post-release monitoring of fish reared under each growth regime.
Survival of fiber cells and fiber-cell messenger RNA in lens of rats maintained on a 50% galactose diet for 45 days

Previous work from this laboratory has shown that in cataractous lens from rats fed a 50% galactose diet up to 32 days, synthesis of crystallin mRNAs was reduced while synthesis of mRNAs for the non-crystallin proteins appeared to be maintained at equivalent or higher levels than found in the controls. In this study, we find that the population of mRNA from the 45-day cataractous lens included all of the crystallin mRNAs and substantial amounts of mRNAs for the non-crystallin proteins, in particular those proteins of molecular weights ranging from 45,000 to 92,000, and pIs from 5.5 to 7.0. At the 45-day cataractous stage, the observed mRNA products totaled between 100 and 120, while for the control they numbered between 40 and 50. In addition, hybrid-select measurements with a lambda gt11 MP26 clone established that MP26 mRNA persisted in the fiber cells of 11-, 20-, 32- and 45-day galactosemic lens. The data, therefore, suggest that continuous exposure of the lens to galactose apparently leads to significant fluctuations in mRNA synthesis and survival. Indirect immunofluorescence (with a monospecific polyclonal rabbit anti-MP26 antibody) and light-microscopy studies demonstrated that although the cortical fiber cells were swollen and structurally disoriented, they retained their nuclei, while the enucleated fiber cells were absent. The microscopy data also suggest that differentiation of the epithelial cells to fiber cells continued in the cataractous lens. Fiber-cell migration was backward as compared with the control, and the surviving cells were localized within the cortex and appeared to be surrounded by damaged cells or cell debris. It is suggested that persistent fiber-cell survival, and continued synthesis of various classes of mRNA by the nucleated cells in the cataractous lens could explain why reversal of cataracts results in recovery in both cell morphology and transparency in the non-nuclear portion of the lens.
Differential effects of safety in extinction of anxious responding to a CO2 challenge in patients with panic disorder.

Safety-relevant parameters are hypothesized to be important to the maintenance of pathological anxiety. The authors examined the effects of safety information and safety cues on anxious responding to a repeated 35% CO 2 challenge in 31 patients with panic disorder. Patients were randomly assigned to one of three conditions: (a) safety information, (b) safety information plus a safety cue, or (c) no safety information. In the safety information group, patients received accurate information regarding the benign effects of the CO 2 challenge. In the combined group, patients also received a safety cue that is salient for many patients with panic disorder (i.e., access to an anxiolytic pill during the challenge). The experimental manipulations did not differentially affect anxious responding following an initial challenge. However, after access to the anxiolytic was removed and the challenge procedure was repeated, those in the safety information alone condition showed lower subjective anxiety compared to those in the combined safety information/safety cue group. Findings suggest that safety information facilitates extinction of anxiety but only in the absence of safety cues.
Development, Characterization, and Application of a Versatile Single Particle Detection Apparatus for Time-Integrated and Time-Resolved Fluorescence Measurements—Part I: Theoretical Considerations

Recent progress in aerosol science has resulted in more challenging demands in the design of new particle beam introduction systems. In this paper, the concept of a variable orifice aerodynamic lens system is presented and supported by the numerical simulation results. This novel particle beam inlet can serve as either a narrow band pass filter (a particle segregator) that only confines particles with a specific size or a broad band pass filter (a particle concentrator) that allows particles with a wide size range to be concentrated on the beam axis. Following a brief description of the inlet system, computational details are described. Simulation of this inlet has been carried out by the commercial computational fluid dynamics protocol FLUENT. Focusing performance and characteristic of single-thin plate orifices have been first revealed and discussed, and then the dynamics and advantages of using multiple lenses with variable orifices are addressed. It is clearly shown that the focusing size range can be primarily adjusted by varying the working pressure, the orifice geometry, and/or the arrangement of orifices. As a result, a selection of the desired particle focusing size range can be achieved without the need of changing the inlet, thus increasing the versatility of the device for a broad range of applications.
A decision model for environmental R&D

Abstract In this paper, a simple decision model is formulated to investigate the optimal funding level for an environmental RD 2) the technical difficulty of the research area; 3) the potential payoffs involved in the decision that may be influenced by the research outcome; and 4) the prior knowledge of the key decision makers. Among other insights, analysis of the model demonstrated that the optimal research expenditure jumped from zero to a significant amount or conversely with small changes in parameters. The jump occurred when the expected cost of an uninformed decision equals the cost of research plus the expected cost of the contingent decision. In addition, the optimal research expenditure was sensitive to the technical difficulty of the research area.
How Globalization Can Cause Fundamental Curriculum Change: An American Perspective

Globalization, unlike 20th century social and economic developments, will cause fundamental rather than merely incremental educational change. `Globalization' refers to a complex of technological and economic factorsincluding the global spread of communicationtechnology networks, and the global integration ofproduct and labor markets. I argue that (1) there is a powerful new alliance among elites and educational consumers for fundamental change; (2) globalization destabilizes the internal processes of school organizations that constrain fundamental change,motivating educators to innovate; (3) globalization erodes the institutional categories of public discourse that hold standard school practice in place, allowing a `shadow institution' of non-standard educational agencies to form; and (4) new synthetic visions of educational institutions in better accord with models of rational action in networked environments, are being formulated; and (5) these are now guiding a convergence of piecemeal innovations towards a fundamentally transformed institutional pattern.
Consequences of restrictive and promotive managerial control among American university professors

Purpose – While managerial influence has received much research attention, Scholl has presented a fairly new approach to examining such influence. This approach distinguishes between restrictive (pushing one's wishes through, although they may run counter to the interests of another) and promotive control (influencing another in a way that is in line with his or her interests). The current research intends to offer a preliminary investigation into the relationships between these control tactics, leader‐member exchange, and organizational commitment.Design/methodology/approach – University faculty members (n=46) completed measures of restrictive and promotive control, leader member exchange and organizational commitment in relation to their department chairs.Findings – Statistical analysis indicates relationships exist between all variables of interest, but that leader‐member exchange mediates several managerial control‐organizational commitment relationships.Research limitations/implications – The main li...
On-the-fly string method for minimum free energy paths calculation

An improved and simplified version of the string method in collective variables for computing minimum free energy paths is proposed. The string is discretized into a finite number of images and in the new method these images are evolved concurrently with replicas of the original system while keeping their inter-distances equal via reparametrization. There is no need to compute the mean force by time-averaging, nor to project the force perpendicularly to the string. In this Letter, the algorithmic aspects of the on-the-fly string method are presented in detail and the method is tested on the solvated alanine dipeptide molecule.
High-pressure pulsatile lavage irrigation of fresh intraarticular fractures: effectiveness at removing particulate matter from bone.

Objective To determine the effectiveness of high-pressure pulsatile lavage (HPL) versus bulb syringe (BS) irrigation in removing particulate matter from metaphyseal cancellous bone. Design Four grams of particulate graphite were placed in twenty distal femoral intraarticular osteotomies performed on New Zealand rabbit hind limbs. Two groups of ten specimens were then irrigated using either HPL or BS irrigation. A representative coronal section from each specimen was then prepared for histologic evaluation using 400x light microscopy. The number and distribution of graphite particles-present as small (less than 20 micrometers), medium (20 to 50 micrometers), and large (greater than 50 micrometers) aggregates-were then recorded. Results The mean maximum perpendicular distance of graphite aggregates of all sizes from the osteotomy site was 12.4 millimeters (+/-SD 2.5) in the HPL group and 12.5 millimeters (+/-SD 2.0) in the BS group (p > 0.5). The mean number of aggregates within four 400x fields (1.08 millimeters) of the osteotomy site was 21.9 (+/-SD 22.0) in the HPL group and 21.8 (+/-SD 27.5) in the BS group (p > 0.5). The mean total number of aggregates in the area surveyed was 129.4 (+/-SD 79.6) in the HPL group and 137.5 (+/-SD 113.6) in the BS group (p > 0.5). Separate analyses controlling for aggregate size of the specimens also revealed no significant differences between HPL and BS irrigation. Conclusion HPL and BS irrigation appear equally effective in removing particulate matter from metaphyseal cancellous bone in an intraarticular fracture model. Furthermore, HPL does not appear to drive particulate matter farther into metaphyseal cancellous bone than BS irrigation.
Development of a high-speed 3-axis machine tool using a novel parallel-kinematics X-Y table

Abstract In this paper we discuss the development and performance evaluation of a high-speed, 3-axis milling machine using a novel parallel kinematics x-y table. The x-y table is based on a an inversion of the Oldham coupling. The advantages of this kinematic configuration include low inertia, uniform kinematic conditioning, and dynamically matched axes. The design of the x-y table makes this system particularly well suited for high-speed contouring in the x-y plane. The kinematics, dynamics, and mechanical design of the system are described. Linear and circular contouring experiments are conducted to evaluate the system capabilities. The stiffness of both the mechanism as well as the direct drive actuation system are measured and reported. The experimental results demonstrate that the proposed mechanism offers an attractive combination of performance characteristics for high-speed contouring and high-speed machining.
Thromboxane A2: an endothelium-derived vasoconstrictor in human internal mammary arteries.

Abstract The internal mammary artery (IMA) has become the conduit of choice for coronary artery bypass grafting. However, the IMA graft can exhibit vasoconstriction during the perioperative period. Experiments were designed to determine the role of cyclooxygenase products in human IMA during hypoxia. Rings of IMA, with and without endothelium, were suspended in organ baths containing physiologic salt solution. Rings were contracted with norepinephrine and then exposed to hypoxia for 15 minutes. In segments with endothelium, hypoxia inducted a transient relaxation followed by contraction. This contraction was associated with a significantly increased production of thromboxane B 2 , the stable metabolite of thromboxane A 2 (n = 10; from 120.7 ± 3.5 pg/mg wet tissue before hypoxia to 175.8 ± 5.2 pg/mg during hypoxia; p 2 could not be detected in samples from organ baths containing IMA segments without endothelium before or during hypoxia. This study demonstrated that endothelium of human IMA grafts releases thromboxane A 2 basally and that production is augmented by hypoxia, which acts to constrict the underlying vascular smooth muscle, increase vascular tone, and promote ischemic events such as vasospasm and thrombosis, particularly in hypoxemic patients.
Applying the Gelberg-Andersen Behavioral Model for Vulnerable Populations to Health Services Utilization in Homeless Women:

We applied the Gelberg-Andersen Behavioral Model for Vulnerable Populations to predict health services utilization (HSU) in 875 homeless US women. Structural models assessed the impact of predisposing (demographics, psychological distress, alcohol/drug problems, homelessness severity), enabling (health insurance, source of care, barriers) and need (illness) variables on HSU (preventive care, outpatient visits, hospitalizations). Homelessness severity predicted illness, barriers and less insurance. Distress predicted more barriers, illness and less outpatient HSU. Drug problems predicted hospitalizations. Barriers predicted more illness and less outpatient HSU. Health and homelessness indicators were worse for White women. Better housing, access to care and insurance would encourage appropriate HSU.
Using Local Trajectory Optimizers to Speed Up Global Optimization in Dynamic Programming

Dynamic programming provides a methodology to develop planners and controllers for nonlinear systems. However, general dynamic programming is computationally intractable. We have developed procedures that allow more complex planning and control problems to be solved. We use second order local trajectory optimization to generate locally optimal plans and local models of the value function and its derivatives. We maintain global consistency of the local models of the value function, guaranteeing that our locally optimal plans are actually globally optimal, up to the resolution of our search procedures.
Epicardial Adipose Tissue and Neural Mechanisms of Atrial Fibrillation

In this issue of Circulation: Arrhythmia and Electrophysiology , Nagashima et al1 reported that there is higher epicardial adipose tissue (EAT) volume and greater serum inflammatory biomarker levels in patients with persistent atrial fibrillation (PerAF) than in patients with paroxysmal atrial fibrillation (PAF). Furthermore, they noted that high dominant frequency (DF) sites are located adjacent to EAT sites. The authors proposed 2 possible explanations for these findings. One is that EAT secretes proinflammatory cytokines that alter local atrial and pulmonary vein (PV) electrophysiology and facilitates the development of atrial fibrillation (AF). The second is that EAT contains abundant ganglionated plexi. Activation of the autonomic nerves in the ganglionated plexi facilitates the maintenance of AF. The results of the present study extended their previous observation on EAT2 by providing new data on the correlation between high DF sites and EAT sites. These novel observations provide new insights into the anatomic and physiological differences between PAF and PerAF. Article see p 676 After the initial diagnosis of PAF, there is a slow (5%–10% per year) but steady progression to chronic (permanent or persistent) AF.3 Baseline echocardiographic variables, age, cardiomyopathy, and heart rate are independently associated with progression to chronic AF. On the other hand, PerAF is also frequently the initial diagnosis without preceding PAF episodes. How often PerAF and permanent forms of AF are preceded by recurrent PAF remains unclear. Improving the understanding of PAF to PerAF progression may help secondary prevention efforts to reduce the complications associated with AF. Wijffels et al4 performed intermittent rapid atrial pacing in goats to study the progression of PAF to PerAF. They found that when AF is maintained artificially, the duration of the paroxysms progressively increases, becoming sustained after 1 to 3 weeks of AF. The transition from PAF to PerAF …
Steric effect: A quantitative description from density functional theory

The concepts of steric energy, steric potential, and steric charge are introduced within the density functional theory framework. The steric energy, representing a hypothetical state with all electrons packed into the lowest orbital and other effects entirely excluded, is a measure of the intrinsic space occupied by an electronic system. It is exclusive, repulsive, and extensive, and it vanishes for homogeneous electron gas. When Bader's zero-flux boundary condition is adopted, atoms in molecules are found to achieve balanced steric repulsion among one another with vanished steric energy density interfaces. A few molecular systems involving conformation changes and chemical reactions have been investigated to examine the relative contribution of the steric and other effects, providing insights for a few controversial topics from a different perspective.
Design optimization of multi-coil resistive magnets

The design of multi-coil resistive magnets can be greatly improved by optimizing the numerous variables involved. We have developed a code that optimizes the design for maximum field. Maximum magnetic field at the center (the objective function) is sought under numerous geometric and mechanical constraints. We apply the penalty method to reduce the constrained problem to a sequence of unconstrained optimizations. The objective function and the majority of the constraints are nonlinear. The BFGS quasi-Newton method is used at the core of the optimization procedure. We give the mathematical problem formulation and describe the code implementation. The method is shown to be easily modified to account for new constraints. Examples of code results and typical nonlinear behavior of the function being minimized are shown.
Ion microbeam radiation system

An ion microbeam radiation test system has been built for studying radiation-induced charge collection and single event upsets in advanced semiconductor circuits. With this system, it is possible to direct an ion beam of a diameter as small as 1 mu m onto a circuit or test structure with a placement accuracy of 1 mu m. The components of the system and its operation are described. Applications are described which demonstrate the capabilities of the system. >
Theoretical studies of displacement deposition of nickel into porous silicon with ultrahigh aspect ratio

A model is developed to address the uniformity of displacement deposition of nickel inside porous silicon with an ultrahigh aspect ratio as high as 200. The nickel distribution is treated as a current distribution issue as in electrodeposition. It is shown that the deposition distribution along the pore depth exhibits a strong dependence on a polarization parameter ξ. High values of ξ correspond to mass transport limitations and lead to non-uniform distributions, whereas small ξ values, representing interfacial reaction control, produce uniform distributions. Non-uniform deposition primarily occurs at an initial stage in which the reaction is dominated by mass transfer. As the deposition process continues, the deposition rate drops to a low value, and the deposition uniformity shifts from Ni 2+ mass transport limitations to its interfacial reaction control, leading to uniform Ni 2+ concentration and deposition rate distributions. It is predicted that the non-uniformity at the initial stage could be remedied by increasing the bulk concentration of the nickel ions and decreasing the plating bath pH. In addition, the uniformity of the deposition distribution can be significantly improved by introducing inhibiting additive coumarin to the plating solution.
An effective treatment protocol for intraarterial drug injection.

Abstract Between 1972 and 1988, 48 patients with extremity ischemia after an intraarterial drug injection were treated with the following protocol: heparin, dextran 40, dexamethasone, elevation, and early mobilization of the extremity. A tissue ischemia score, derived by assessing the color, capillary refill, sensory function, and temperature of the extremity, was used to assess the ischemic injury. Each sign was scored either normal=0 or abnormal=1; then summed to provide the tissue ischemia score (range, 0 to 4). Twenty-four (50%) patients had an extremity tissue ischemia score ≤2. After treatment 22 of the 24 patients had a normal extremity, and 2 required limited digital amputations. In this group, outcome was comparable regardless of the time interval from intraarterial drug injection to treatment. Ten of 24 (50%) patients with an extremity tissue ischemia score >2 had a normal extremity, 3 had a functional deficit, and 11 required digital amputations. Twelve of the 24 patients were treated within 24 hours and had a significantly superior outcome when compared to the 12 who were treated more than 24 hours after intraarterial drug injection ( p
Network reconfiguration in distribution systems for loss reduction and load balancing

A general formulation of the feeder reconfiguration problem for loss reduction and load balancing is given, and a novel solution method is presented. The solution uses a search over different radial configurations created by considering switchings of the branch exchange type. To guide the search, two different power flow approximation methods with varying degrees of accuracy have been developed and tested. The methods are used to calculate the new power flow in the system after a branch exchange and they make use of the power flow equations developed for radial distribution systems. Both accuracy analysis and the test results show that estimation methods can be used in searches to reconfigure a given system even if the system is not well compensated and reconfiguring involves load transfer between different substations. For load balancing, a load balance index is defined and it is shown that the search and power flow estimation methods developed for power loss reduction can also be used for load balancing since the two problems are similar. >
Uncoupling of Genomic and Epigenetic Signals in the Maintenance and Inheritance of Heterochromatin Domains in Fission Yeast

Many essential aspects of genome function, including gene expression and chromosome segregation, are mediated throughout development and differentiation by changes in the chromatin state. Along with genomic signals encoded in the DNA, epigenetic processes regulate heritable gene expression patterns. Genomic signals such as enhancers, silencers, and repetitive DNA, while required for the establishment of alternative chromatin states, have an unclear role in epigenetic processes that underlie the persistence of chromatin states throughout development. Here, we demonstrate in fission yeast that the maintenance and inheritance of ectopic heterochromatin domains are independent of the genomic sequences necessary for their de novo establishment. We find that both structural heterochromatin and gene silencing can be stably maintained over an ∼10-kb domain for up to hundreds of cell divisions in the absence of genomic sequences required for heterochromatin establishment, demonstrating the long-term persistence and stability of this chromatin state. The de novo heterochromatin, despite the absence of nucleation sequences, is also stably inherited through meiosis. Together, these studies provide evidence for chromatin-dependent, epigenetic control of gene silencing that is heritable, stable, and self-sustaining, even in the absence of the originating genomic signals.
Arsenic Trioxide Is a Potent Inhibitor of the Interaction of SMRT Corepressor with Its Transcription Factor Partners, Including the PML-Retinoic Acid Receptor α Oncoprotein Found in Human Acute Promyelocytic Leukemia

The SMRT corepressor complex participates in transcriptional repression by a diverse array of vertebrate transcription factors. The ability to recruit SMRT appears to play a crucial role in leukemogenesis by the PML-retinoic acid receptor α (RARα) oncoprotein, an aberrant nuclear hormone receptor implicated in human acute promyelocytic leukemia (APL). Arsenite induces clinical remission of APL through a incompletely understood mechanism. We report here that arsenite is a potent inhibitor of the interaction of SMRT with its transcription factor partners, including PML-RARα. Arsenite operates, in part, through a mitogen-activated protein (MAP) kinase cascade culminating in phosphorylation of the SMRT protein, dissociation of SMRT from its nuclear receptor partners, and a relocalization of SMRT out of the nucleus into the cytoplasm of the cell. Conversely, inhibition of this MAP kinase cascade attenuates the effects of arsenite on APL cells. Our results implicate SMRT as an important biological target for the actions of arsenite in both normal and neoplastic cells.
Metal ion catalysis in chemisorption anddehydrogenation of alkanes on aluminium hydroxide clusters, revealed bytheoretical calculations

Electron-correlated DFT calculations with a large basis set show that propane adds to coordinatively unsaturated aluminium, as in the clusters (HO)3Al(OH2)x (x = 0, 1), by aluminium insertion into a C–H bond, followed by hydrogen migration to an oxygen atom and predict correctly experimental observations; the alternative pathway involving alkyl–oxygen interaction has a much higher energy barrier and does not predict correctly the experimental results.
Expression of membrane-bound HLA-G at the maternal-fetal interface is not associated with pregnancy maintenance among patients with idiopathic recurrent pregnancy loss.

Recurrent pregnancy loss (RPL) has many known aetiologies. However, using current diagnostic testing, a large fraction of recurrent pregnancy losses remain unexplained. Many of these may have immune underpinnings. HLA-G is a non-classical MHC class I product whose fairly restricted expression at the maternal‐fetal interface suggests a role in successful embryonic implantation and/or subsequent pregnancy maintenance. The study of immune-mediated RPL should be enhanced by comparing groups of idiopathic RPL patients with normal fetal chromosomes to RPL patients with known chromosomal abnormalities in their index pregnancies. We hypothesized that if alteration of HLA-G expression at the maternal‐fetal interface were associated with immune-mediated RPL, such changes might be detectable using these comparisons. HLA-G protein expression at the maternal‐fetal interface in maternal and gestational age-matched women with history of idiopathic RPL and normal male fetuses were compared with expression in RPL patients with known fetal trisomy 16 in their index pregnancy. We detected no significant quantitative differences in the levels of HLA-G between these groups of RPL patients. Within the limitations of this study, we conclude that HLA-G expression is not a major immunological determinant of pregnancy maintenance among patients with idiopathic RPL.
Studies on the development of Rhodnius prolixus and the effects of its symbiote Nocardia rhodnii.

Rhodnius prolixus Stal (Hemiptera: Reduviidae) is the host of an actinomycete, Nocardia rhodnii , in nature. Intermolt periods of laboratory-reared R. prolixus were shorter when the bugs were raised aposymbiotically on mouse blood compared to those raised on rabbit blood. Control groups of contaminated R. prolixus fed on mice and rabbits had similar although slightly longer intermolt periods than those grown without the symbiote on mouse blood.
All Spiking, Sustained ON Displaced Amacrine Cells Receive Gap-Junction Input from Melanopsin Ganglion Cells

Retinal neurons exhibit sustained versus transient light responses, which are thought to encode low- and high-frequency stimuli, respectively. This dichotomy has been recognized since the earliest intracellular recordings from the 1960s, but the underlying mechanisms are not yet fully understood. We report that in the ganglion cell layer of rat retinas, all spiking amacrine interneurons with sustained ON photoresponses receive gap-junction input from intrinsically photosensitive retinal ganglion cells (ipRGCs), recently discovered photoreceptors that specialize in prolonged irradiance detection. This input presumably allows ipRGCs to regulate the secretion of neuromodulators from these interneurons. We have identified three morphological varieties of such ipRGC-driven displaced amacrine cells: (1) monostratified cells with dendrites terminating exclusively in sublamina S5 of the inner plexiform layer, (2) bistratified cells with dendrites in both S1 and S5, and (3) polyaxonal cells with dendrites and axons stratifying in S5. Most of these amacrine cells are wide field, although some are medium field. The three classes respond to light differently, suggesting that they probably perform diverse functions. These results demonstrate that ipRGCs are a major source of tonic visual information within the retina and exert widespread intraretinal influence. They also add to recent evidence that ganglion cells signal not only to the brain.
Frequency and time to onset of community-acquired respiratory tract infections in patients receiving esomeprazole: a retrospective analysis of patient-level data in placebo-controlled studies.

Summary Background Debate continues on whether a causal association exists between the use of proton pump inhibitors (PPIs) and the risk of respiratory tract infections, in particular pneumonia. Aim To investigate the occurrence of community-acquired respiratory tract infections, including pneumonia, in patients receiving esomeprazole. Method A retrospective investigation of pooled data on adverse events related to respiratory tract infections, originally reported in 24 randomised, double-blind clinical studies, was conducted. The frequencies of respiratory tract infections and their relative risks were calculated retrospectively for the total patient population (9602 patients receiving esomeprazole and 5500 receiving placebo) and for sub-populations defined according to sex, age, esomeprazole dose, indication and geographical region. The cumulative frequency of first occurrence of events was calculated over 180 days. Results Frequencies of respiratory tract infections were similar in patients receiving esomeprazole and in those receiving placebo (any respiratory tract infection or signs/symptoms potentially indicating an respiratory tract infection, 0.278 and 0.296 patients per patient-year; lower respiratory tract infections, 0.048 and 0.058 per patient-year; pneumonia, 0.006 and 0.009 per patient-year, respectively). The relative risk for any respiratory tract infection in patients receiving esomeprazole compared with placebo was 0.94 (95% CI, 0.86–1.04). For lower respiratory tract infections, the relative risk was 0.82 (95% CI, 0.65–1.03) and for pneumonia, 0.66 (95% CI, 0.36–1.22). Sub-analyses by demographics, dose and indication yielded similar results to the overall analysis. The occurrence of respiratory tract infections was evenly distributed over time and similar in the esomeprazole and placebo groups. Conclusion There is no causal association between treatment with esomeprazole and the occurrence of community-acquired respiratory tract infections, including pneumonia.