cssi/SciSciGPT-SciSciNet huggingface dataset:
PK11195 labels activated microglia in Alzheimer's disease and in vivo in a mouse model using PET.

Activated microglia may promote neurodegeneration in Alzheimer’s disease (AD) and may also help in amyloid clearance in immunization therapies. In vivo imaging of activated microglia using positron emission tomography (PET) could assist in defining the role of activated microglia during AD progression and therapeutics. We hypothesized that PK11195, a ligand that binds activated microglia, could label these cells in postmortem AD tissues and in vivo in an animal model of AD using PET. [ 3 H](R)-PK11195 binding was significantly higher in AD frontal cortex compared to controls and correlated mainly with the abundance of immunohistochemically labeled activated microglia. With age, the brains of APP/PS1 transgenic mice showed progressive increase in [ 3 H](R)-PK11195 binding and [ 11 C](R)-PK11195 retention in vivo assessed using microPET, which correlated with the histopathological abundance of activated microglia. These results suggest that PK11195 binding in AD postmortem tissue and transgenic mice in vivo correlates with the extent of microglial activation and may help define the role of activated microglia in the pathogenesis and treatment of AD.
Ex post ≠ ex ante: Determining liability in hindsight.

Participants in three conditions (foresight, hindsight, and a modified hindsight condition designed to ameliorate the hindsight effect) assessed whether a municipality should take, or have taken, precautions to protect a riparian property owner from flood damage. In the foresight condition, participants reviewed evidence in the context of an administrative hearing. Hindsight participants reviewed parallel materials in the context of a trial. Three quarters of the participants in foresight concluded that a flood was too unlikely to justify further precautions-a decision that a majority of the participants in hindsight found to be negligent. Participants in hindsight also gave higher estimates for the probability of the disaster occurring. The debiasing procedure failed to produce any significant differences from the regular hindsight condition. The results suggest that absent an effective debiasing technique, risk assessments made in foresight will be judged harshly in hindsight.
Radio-frequency catheter ablation of cardiac arrhythmias: Appraisal of an evolving therapeutic modality

Since its introduction in 1985, there have been numerous reports of the use of radio-frequency (RF) current as an alternative energy source for catheter ablation. RF current (frequency range 150 kHz to 1 MHz), when delivered in bipolar mode, causes desiccation of tissue by creating a localized area of heat that results in discrete coagulation necrosis. An equivalent energy source such as direct current (DC) shock can be delivered at lower power (5 to 30 W) and lower voltage (30 to 80 V) for a longer pulse duration (10 to 60 seconds), thus eliminating barotraumatic effects. Because of its high frequency, RF current does not stimulate neuromuscular fibers, and general anesthesia during ablation is not needed. Studies in animals have shown that catheter-delivered RF energy can safely produce permanent complete or partial AV block, necrosis of atrial and ventricular myocardium adjacent to the mitral and tricuspid anuli potentially suitable for ablation of accessory pathways, and discrete lesions in the left and right ventricular myocardium. Recently, investigators from several centers have reported successful ablation of the AV junction (either complete or partial AV block) in patients with refractory supraventricular tachyarrhythmias, ablation of accessory pathways, and ablation of focal ventricular myocardium or a segment of a bundle branch in patients with drug-resistant ventricular tachycardia. Specific modification of AV conduction to cure AV nodal reentrant tachycardia has been successfully attempted. In all studies the application of RF current has not caused any serious complications.(ABSTRACT TRUNCATED AT 250 WORDS)
Smoothing of Noisy Laser Scanner Generated Meshes Using Polynomial Fitting and Neighborhood Erosion

This paper presents a method for removing geometric noise from triangulated meshes while preserving edges and other intended geometric features. The method iteratively updates the position of each mesh vertex with a position lying on a locally fitted bivariate polynomial. The user selects the width of the vertex neighborhood, the order of the fitted polynomial, and a threshold angle to control the effects of the smoothing operation. To avoid smoothing over discontinuities, the neighborhood can be eroded by removing vertices with normals that deviate beyond a threshold from the estimated median normal of the neighborhood. The method is particularly suitable for use on laser scanner generated meshes of automobile outer body panels. Smoothing methods used on these meshes must allow C 2 continuous equilibrium surfaces and must minimize shrinkage. Despite the abundance of existing smoothing schemes, none addresses both of these specific problems. This paper demonstrates the effectiveness of our method with both synthetic and real world examples. @DOI: 10.1115/1.1737381#
The effects of monocular lid suture upon the development of the lateral geniculate nucleus in squirrels (Sciureus carolinensis).

Three infant squirrels had the lids of one eye sutured prior to eye opening. The animals were killed when they were adults and the cells in the lateral geniculate nucleus were studied after Nissl staining. The nerve cells within the deprived geniculate layers are smaller than the normally innervated cells. However, this asymmetry is seen only in the segment of the lateral geniculate nucleus that receives its inputs from the binocular portion of the visual field. Areas receiving from the monocular portion show no significant changes in cell size or cell packing. Thus, visual deprivation by itself does not affect perikaryal growth in the lateral geniculate nucleus. Growth is affected only in those parts of the geniculo-cortical system in which the deprived cells have to compete with cells that are normally innervated.
A coat for all sequences

A new RNA aptamer–protein co-crystal surprisingly shows that bacteriophage MS2 coat protein uses a similar set of contacts to bind both a native RNA ligand and an RNA hairpin with a different secondary structure.
Understanding environmental influences on performing password-based mobile authentication

In a mobile environment, text-based passwords are still the most common mechanism for user authentication. Although various studies have been conducted to investigate what password composition policies are better oriented for mobile users, a limited study has been performed to understand the impact of password composition policies and environmental settings to mobile users' password typing abilities. In this paper, we present a study that investigates password strength, user behavior, and user sentiment across two password composition policies under two environmental conditions such as stationary (sedentary position) and on-the-go (while walking). From the study, we correlate our results with user behaviors under different environmental conditions to provide suggestions for password-composition policies for mobile-based authentication.
Activator-sigma interaction: A hydrophobic segment mediates the interaction of a sigma family promoter recognition protein with a sliding clamp transcription activator.

Activation of transcription at bacteriophage T4 late promoters and coupling of late transcription to concurrent replication requires a peculiar transcriptional activator, the gp45 sliding clamp of the T4 DNA polymerase. In order to activate transcription, the topologically DNA-linked trimeric gp45 must interact with two T4-encoded RNA polymerase-binding proteins, the gp33 co-activator, and the gp55 late sigma factor. The carboxy termini of gp55 and gp33 share a similar sequence, which has been shown to be required for response of late transcription to activation by gp45. Alanine-scanning mutagenesis of the C terminus of gp55 shows that residues within the short hydrophobic sequence L(D/A)FLYE, are necessary for gp55 to bind to gp45, and to respond maximally to transcriptional activation by gp45. When fused to GST, the peptide SLDFLYE suffices for specific gp45 binding. Thus, it constitutes the main gp55 epitope for gp45 interaction.
Chaperonin-mediated protein folding : fate of substrate polypeptide

Chaperonins are megadalton ring assemblies that mediate essential ATP-dependent assistance of protein folding to the native state in a variety of cellular compartments, including the mitochondrial matrix, the eukaryotic cytosol, and the bacterial cytoplasm. Structural studies of the bacterial chaperonin, GroEL, both alone and in complex with its co-chaperonin, GroES, have resolved the states of chaperonin that bind and fold non-native polypeptides. Functional studies have resolved the action of ATP binding and hydrolysis in driving the GroEL-GroES machine through its folding-active and binding-active states, respectively. Yet the exact fate of substrate polypeptide during these steps is only poorly understood. For example, while binding involves multivalent interactions between hydrophobic side-chains facing the central cavity of GroEL and exposed hydrophobic surfaces of the non-native protein, the structure of any polypeptide substrate while bound to GroEL remains unknown. It is also unclear whether binding to an open GroEL ring is accompanied by structural changes in the non-native substrate, in particular whether there is an unfolding action. As a polypeptide-bound ring becomes associated with GroES, do the large rigid-body movements of the GroEL apical domains serve as another source of a potential unfolding action? Regarding the encapsulated folding-active state, how does the central cavity itself influence the folding trajectory of a substrate? Finally, how do GroEL and GroES serve, as recently recognized, to assist the folding of substrates too large to be encapsulated inside the machine? Here, such questions are addressed with the findings available to date, and means of further resolving the states of chaperonin-associated polypeptide are discussed.
A method for analyzing temporal patterns of variability of a time series from Poincare plots.

The Poincare plot is a popular two-dimensional, time series analysis tool because of its intuitive display of dynamic system behavior. Poincare plots have been used to visualize heart rate and respiratory pattern variabilities. However, conventional quantitative analysis relies primarily on statistical measurements of the cumulative distribution of points, making it difficult to interpret irregular or complex plots. Moreover, the plots are constructed to reflect highly correlated regions of the time series, reducing the amount of nonlinear information that is presented and thereby hiding potentially relevant features. We propose temporal Poincare variability (TPV), a novel analysis methodology that uses standard techniques to quantify the temporal distribution of points and to detect nonlinear sources responsible for physiological variability. In addition, the analysis is applied across multiple time delays, yielding a richer insight into system dynamics than the traditional circle return plot. The method is applied to data sets of R-R intervals and to synthetic point process data extracted from the Lorenz time series. The results demonstrate that TPV complements the traditional analysis and can be applied more generally, including Poincare plots with multiple clusters, and more consistently than the conventional measures and can address questions regarding potential structure underlying the variability of a data set.
Effect of Soil Type and Exposure Duration on Mortality and Transfer of Chlorantraniliprole and Fipronil on Formosan Subterranean Termites (Isoptera: Rhinotermitidae)

The uptake and potential transfer of chlorantraniliprole and fipronil by the Formosan subterranean termite, Coptotermes formosanus Shiraki, was investigated in the laboratory by using donor-recipient model bioassays. Two different types of substrates, sandy loam soil (18.6% organic matter) and sand (0.19% organic matter), were used to evaluate how these treated substrates impact the direct mortality and transfer efficiency of the two nonrepellent termiticides tested at different concentrations. Chlorantraniliprole exhibited a more delayed mortality on termites than fipronil in sand. In soil, chlorantraniliprole did not cause higher mortality to either donor or recipient termite at any of the tested concentrations during a 21-d test period when compared with controls. Compared with the controls, a greater number of donors died in the soil treated with fipronil at 14 h postinteraction, and higher death of recipients occurred at 21 d but only in the 60-ppm concentration tested. Our data showed that chlorantraniliprole performed best in substrate with low organic matter against C. formosanus.
A spectral overlay method for dissimilar materials

The spectral overlay method is applied to examine the stress distribution along the interface between the two different materials. The essential feature of the spectral overlay method is that the high resolution of localized steep gradients can be achieved by overlaying a spectral interpolant on a standard finite element mesh. In order to evaluate this method and compare it with conventional finite element method, a test problem with high gradients in Poisson equation has been devised. The results show that this method is very powerful in capturing the shape of the gradient field and its peak value. Solutions for two problems with interfaces between dissimilar materials are then given to illustrate the effectiveness of this method.
A Heparin-sensitive Phospholipase A2 and Prostaglandin Endoperoxide Synthase-2 Are Functionally Linked in the Delayed Phase of Prostaglandin D2 Generation in Mouse Bone Marrow-derived Mast Cells

Abstract BALB/cJ mouse bone marrow-derived mast cells (BMMC) developed with interleukin (IL)-3 can be stimulated by c-kit ligand (KL) in the presence of IL-10 and IL-1β for sequential immediate and delayed generation of prostaglandin (PG) D2 through utilization of constitutive prostaglandin endoperoxide synthase (PGHS) −1 and induced PGHS-2, respectively (Murakami, M., Matsumoto, R., Austen, K. F., and Arm, J. P. (1994) J. Biol. Chem. 269, 22269-22275). We now report that BALB/cJ BMMC stimulated with KL + IL-10 + IL-1β also exhibit the biphasic release of [3H]arachidonic acid with an immediate phase over the first 10 min followed by a delayed phase from 2 to 7 h. The delayed phase of arachidonic acid release and of PGD2 generation was inhibited by heparin, which concomitantly released a phospholipase (PL) A2 from the cells into the supernatant. Both dexamethasone and a type II PLA2 inhibitor, 12-epi-scalaradial, suppressed delayed-phase PGD2 generation at concentrations that did not affect immediate eicosanoid generation. Transcripts for type IIA PLA2, as assessed by reverse transcription-polymerase chain reaction, were progressively induced in BALB/cJ BMMC treated for 2 to 7 h with KL + IL-10 + IL-1β; the induction of these transcripts was down-regulated by 10−6 M dexamethasone. The expression of steady-state transcripts and protein for cytosolic PLA2 (cPLA2) did not change. PGHS-2-dependent delayed-phase PGD2 generation elicited by IgE-dependent activation of BALB/cJ BMMC primed with KL + IL-10 was also accompanied by the induction of type IIA PLA2 transcripts and was suppressed by heparin, with concomitant release of PLA2 into the supernatant. However, both the direct, cytokine-stimulated and the cytokine-primed, IgE-dependent, delayed-phase PGD2 generation occurred in BMMC from C57BL/6J mice, which have a natural disruption of the type IIA PLA2 gene. Thus, kinetic, pharmacologic, and genetic analyses suggest that an inducible, heparin-sensitive PLA2, rather than cPLA2, provides arachidonic acid to concomitantly induced PGHS-2 for delayed-phase PGD2 biosynthesis in activated BMMC. Furthermore, this heparin-sensitive PLA2 likely represents a novel PLA2 or a new function for a known low molecular weight PLA2.
An electrochemical study of the Fe(III)/Fe(II) electrode reaction in the aluminum chloride+N-(n-butyl)pyridinium chloride molten salt system

Abstract The Fe(III)/Fe(II) electrode reaction was studied in the room temperature molten salt 2:1 molar ratio aluminum chloride+N-(n-butyl)pyridinium chloride at 30°C and in the 1:1 molar ratio aluminum chloride+N-(n-butyl)pyridinium chloride melt at 35°C. Techniques employed for this study were rotating disc electrode voltammetry, cyclic voltammetry and potentiometry. The results obtained in the 2:1 melt indicate that the charge transfer for reduction of Fe(III) is only moderately rapid (quasi-reversible) at glassy carbon and tungsten electrodes. In contrast the rate of reduction of Fe(III) appears to be mass transport controlled in 1:1 melt at these electrodes. Values of the standard heterogeneous rate constant, transfer coefficient, diffusion coefficient, and standard potential are reported for the Fe(III)/Fe(II) system.
A genetic algorithm approach to the design of ultra‐thin electromagnetic bandgap absorbers

A design methodology is presented for utilizing electromagnetic bandgap metamaterials, also known as artificial magnetic conductors, to realize ultra-thin absorbers. One approach that has recently been proposed is to place a resistive sheet in close proximity to a frequency-selective surface acting as an artificial magnetic conductor. However, we demonstrate in this paper that incorporating the loss directly into the frequency selective-surface can eliminate the additional resistive sheet, thereby further reducing the overall thickness of the absorber. The geometrical structure and corresponding resistance of this lossy frequency-selective surface is optimized by using a genetic algorithm to achieve the thinnest possible absorber. Two examples of genetically engineered electromagnetic bandgap metamaterial absorbers are presented and discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 61–64, 2003
The size distribution for Markov equivalence classes of acyclic digraph models

Bayesian networks, equivalently graphical Markov models determined by acyclic digraphs or ADGs (also called directed acyclic graphs or dags), have proved to be both effective and efficient for representing complex multivariate dependence structures in terms of local relations. However, model search and selection is potentially complicated by the many-to-one correspondence between ADGs and the statistical models that they represent. If the ADGs/models ratio is large, search procedures based on unique graphical representations of equivalence classes of ADGs could provide substantial computational efficiency. Hitherto, the value of the ADGs/models ratio has been calculated only for graphs with n = 5 or fewer vertices. In the present study, a computer program was written to enumerate the equivalence classes of ADG models and study the distributions of class sizes and number of edges for graphs up to n = 10 vertices. The ratio of ADGs to numbers of classes appears to approach an asymptote of about 3.7. Distributions of the classes according to number of edges and class size were produced which also appear to be approaching asymptotic limits. Imposing a bound on the maximum number of parents to any vertex causes little change if the bound is sufficiently large, with four being a possible minimum. The program also includes a new variation of orderly algorithm for generating undirected graphs.
Preparation and characterization of DL-(I- 14 C)- and D-(--)- -amino-n-butyric acid.

Abstract The preparation of DL -[1- 14 C ]-β-amino-n-butyric acid from [1-14C]vinylacetic acid, and the large scale preparation of D -(−)-β- amino -n- butyric acid from DL -β- amino -n- butyric acid by a microbiological method are described. A method for estimating the relative amounts of the D- and L-isomers of β-amino-n-butyric acid as their L-glutamyl derivatives is reported.
A training manual for geriatric education for patients and residents

A significant portion of the practice of most family practitioners includes the care of the older person. One area of significant magnitude within the geriatric curriculum of a family medicine program is the area of patient information and patient education. The need to improve residents knowledge and skills in providing patient information and education to older persons led to the development of a resident and patient education training manual. In this paper, the authors describe the development of the manual in terms of the nature of the content to be learned, the nature of the resident as learner, the nature of the patient as learner, and the nature of the instruction in a community based family practice program.
Cardiac retransplantation is an efficacious therapy for primary cardiac allograft failure.

Although orthotopic heart transplantation has been an effective treatment for end-stage heart failure, the incidence of allograft failure has increased, necessitating treatment options. Cardiac retransplantation remains the only viable long-term solution for end-stage cardiac allograft failure. Given the limited number of available donor hearts, the long term results of this treatment option need to be evaluated. 709 heart transplants were performed over a 20 year period at our institution. Repeat cardiac transplantation was performed in 15 patients (2.1%). A retrospective analysis was performed to determine the efficacy of cardiac retransplantation. Variables investigated included: 1 yr and 5 yr survival, length of hospitalization, post-operative complications, allograft failure, recipient and donor demographics, renal function, allograft ischemic time, UNOS listing status, blood group, allograft rejection, and hemodynamic function. Etiology of primary graft failure included transplant arteriopathy (n = 10), acute rejection (n = 3), hyperacute rejection (n = 1), and a post-transplant diagnosis of metastatic melanoma in the donor (n = 1). Mean age at retransplantation was 45.5 ± 9.7 years. 1 and 5 year survival for retransplantation were 86.6% and 71.4% respectively, as compared to 90.9% and 79.1% for primary transplantation. Mean ejection fraction was 67.3 ± 12.2% at a mean follow-up of 32.6 ± 18.5 mos post-retransplant; follow-up biopsy demonstrated either ISHLT grade 1A or 0 rejection (77.5 ± 95.7 mos post-transplant). Cardiac retransplantation is an efficacious treatment strategy for cardiac allograft failure.
Confirming Sγ products by blending isotopic doublets of HCl

Abstract Experimental confirmation is reported of a published technique, (2) applicable to the square root region which specifies the degree to which two Lorentz absorption lines, not necessarily equal, overlap. It also specifies the deficiency, γ, of the aggregate equivalent width of the blend from its value when the two lines are completely independent. The experiment was conducted at room temperature using pure HCl gas in a 3·34 m path at pressures from 2 to 750 torr. It consisted of sequentially pressure blending fundamental band isotopic doublets. The blended equivalent width of each doublet was compared to predictions from the aforementioned theory as a function of pressure, using previously published values of S and γ as the basis for its application. Published line strength values for the HCl fundamental band agree well only in the upper R ( J ≥7) branch. These were used to test the procedure. Predictions based upon divergent line strengths in the remainder of the band were then compared to the experimental results and confirm the accuracy of the S γ products of Benedict et al. (1) A polynomial representation of the Ladenburg-Reiche function is given which is useful in extending the procedure of Ref. (2) to the linear region. Finally, a new experiment is described, based upon the confirmed theory, which allows the validity of the Lorentz shape to be assessed as a function of pressure for various foreign broadeners and interaction potentials. Application to cometary abundance determinations is also discussed.
Further in vivo studies on attenuating morphine withdrawal: isoform-selective nitric oxide synthase inhibitors differ in efficacy

The N-methyl-D-aspartate (NMDA) receptor-nitric oxide (NO) pathway has been linked to opiate withdrawal. Pretreatments with four inhibitors of NO synthase, 7-nitro indazole, 3-bromo-7-nitro indazole, S-methyl-L-thiocitrulline and aminoguanidine, which exhibit different isoform selectivity in vitro, were evaluated for their ability to attenuate signs of naloxone-precipitated morphine withdrawal. In separate experiments, effects of NO synthase inhibitors on blood pressure were measured in naive and morphine-dependent rats. 7-Nitro indazole, 3-bromo-7-nitro indazole and S-methyl-L-thiocitrulline, which are specific inhibitors of the constitutive isoforms, produced dose-dependent reductions of several signs of withdrawal. Blood pressure was unaffected by the indazoles, whereas S-methyl-L-thiocitrulline produced a strong vasoconstrictor response. Aminoguanidine, which selectively inhibits inducible NO synthase, reduced fewer signs of opioid withdrawal, had a lower relative potency and exhibited no vasopressor activity. These data suggest that constitutive isoforms, but not the inducible isoform of NO synthase, have a primary role in NO-mediated processes that modulate the opioid withdrawal syndrome in the rat.
Rapid determination of hidden rheumatoid factor

A method for the determination of hidden 19S IgM rheumatoid factor based on separation by QAE-Sephadex A-50 chromatography followed by hemolytic assay is described. Hidden rheumatoid factor titers and IgM recoveries of sera were comparable to those obtained by the conventional acid gel filtration method. The QAE method saves time, requires only 250 microliters of serum and can be performed with a minimum of specialized equipment.
The cerebellum and spatial ability: dissection of motor and cognitive components with a mouse model system

The cerebellum has recently been linked to spatial navigation, as indicated by the inferior performance of cerebellar mutant or cerebellar lesioned animals in the water maze. The inability to dissociate motor from cognitive deficits in the impaired water maze performance has been a confounding variable in previous studies, however. In this study, we sought to define clearly the role of the cerebellar system in spatial navigation outside of motor control by creating a mouse model of Purkinje cell loss with intact motor ability, and testing these mice in the water maze. To this end, we made aggregation chimeras between Lc/+ mice, which lose all Purkinje cells postnatally, and +/+ control mice. Lc/+ mice are ataxic and show impaired rotor-rod performance. By contrast, we show that Lc/+ left arrow over right arrow +/+ chimeras above a threshold of Purkinje cell loss show no outward signs of motor impairment and demonstrated normal rotor-rod ability. In the water maze, we found that Lc/+ mice showed impaired performance in the place, cue and platform removal tasks, whereas Lc/+ left arrow over right arrow +/+ chimeras performed similarly to controls in all tasks. We found that the impaired performance in the water maze of Lc/+ mice resulted from both motor as well as cognitive impairment that could be separated from one another by statistical means. In addition, through the analysis of individual chimeric mice, the relationships between these deficits and the total number of Purkinje cells were determined and a specific role for Purkinje cells in search strategy was identified.
Parametric study of a corrosion model applied to lead–bismuth flow systems

Abstract The corrosion of steels exposed to flowing liquid metals is influenced by local and axial conditions of the flow systems. Despite of this, most existing corrosion models only consider the mean values based on local conditions. The present study refines a model for flowing liquid metal under non-isothermal conditions. The model is based on solving the mass transport equation in the boundary layer. Two kinds of flows are investigated: through an open pipe system and through a closed loop system. The model is applied to a lead–bismuth eutectic (LBE) test loop. A parametric study illustrates the effects of the axial temperature profile on corrosion. The study provides important insight to the design, operation and testing of such loop systems.
Power and energy in linearized physical systems

Abstract Although no truly linear physical systems exist, linearized system models are very often used in practice to study the dynamics of real systems and components. Here, the relations between the power and energy in a non-linear physical system and the analogous quantities associated with variables representing small deviations from steady-state values are studied. Sometimes a linearized system is energetically similar to the non-linear system from which it was derived, and in other cases, new types of energy elements appear which were not present in the original system. In order to show the structure of the systems, the results are presented in both equation form and in the form of bond graphs which are unique in exhibiting the power and energy structure of system models.
Properties of doubly-truncated gamma variables

The truncated gamma distribution has been widely studied, primarily in life-testing and reliability settings. Most work has assumed an upper bound on the support of the random variable, i.e. the space of the distribution is (0,u). We consider a doubly-truncated gamma random variable restricted by both a lower (l) and upper (u) truncation point, both of which are considered known. We provide simple forms for the density, cumulative distribution function (CDF), moment generating function, cumulant generating function, characteristic function, and moments. We extend the results to describe the density, CDF, and moments of a doubly-truncated noncentral chi-square variable.
Paper: Emerging medical applications of virtual reality: A surgeon's perspective

Medical applications for virtual reality (VR) technologies are just beginning to emerge. These include VR surgical simulators, telepresence surgery, complex medical database visualization, and rehabilitation. These applications are mediated through the computer interface and embody VR as an integral part of a paradigm shift in the field of medicine. The Green Telepresence Surgery System consists of two components, the surgical workstation and the remote worksite. At the remote site there is a 3-D camera system and responsive manipulators with sensory input. At the workstation there is a 3-D monitor and dexterous handles with force feedback. The VR surgical simulator is a stylized recreation of the human abdomen with several essential organs. Using a head-mounted display and DataGlove^(TM), a person can learn anatomy from a new perspective by 'flying' inside and around the organs, or can practice surgical procedures with a scalpel and clamps. Database visualization creates 3-D images of complex medical data for new perspectives in analysis. VR applications in rehabilitation medicine permit impaired individuals to perform tasks not otherwise available to them, allow accurate assessment and therapy for their disabilities, and help architects understand their critical needs in public or personal space. And to support these advanced technologies, the operating room and hospital of the future will be first designed and tested in virtual reality, bringing together the full power of the digital physician.
New approaches in analysis of soft X-rays using gratings

Abstract The properties of the state-of-the art transmission gratings are discussed and put in context with reflection gratings, zone plates and multi-layer mirrors. Efficiency as well as resolution of the systems are comparable but the different approaches have widely different emphasis and fields of application. The importance of alignment and continuous monitoring of the performance of a grazing incidence monochromator is emphasized and results from an analysis of alignment effects are presented. New developments in multiple combinations of different optical elements are discussed and proposed as important applications of synchrotron radiation.
Involuntary attention and brightness contrast

Carrasco, Ling, and Read (2004) reported that involuntary attention increased perceived contrast. We replicated Carrasco et al. and then tested anaalternative hypothesis: With stimuli near threshold, a peripheral cue biased observers to believe a stimulus had been presented in the cued location. Consistent with this hypothesis, the effect disappeared when we used higher-contrast stimuli. We further tested the guessing-bias hypothesis in three ways: (1) In a detection experiment, the cue affected bias, but did not increase d'; (2) when the cue followed the stimulus, we obtained the same results as when the cue preceded the stimulus; (3) in one experiment, some trials contained no stimulus, yet observers responded that the cued blank stimulus had higher contrast than the uncued blank stimulus. The results suggest that the effects of a noninformative peripheral cue are best described in terms of nonperceptual biases.
The NCI60 human tumour cell line anticancer drug screen

The US National Cancer Institute (NCI) 60 human tumour cell line anticancer drug screen (NCI60) was developed in the late 1980s as an in vitro drug-discovery tool intended to supplant the use of transplantable animal tumours in anticancer drug screening. This screening model was rapidly recognized as a rich source of information about the mechanisms of growth inhibition and tumour-cell kill. Recently, its role has changed to that of a service screen supporting the cancer research community. Here I review the development, use and productivity of the screen, highlighting several outcomes that have contributed to advances in cancer chemotherapy.
Inhibition of antigen-presenting cell functions by alcohol: implications for hepatitis C virus infection

The mechanisms of alcohol-induced immunosuppression include defects in innate and adaptive immune responses. Monocytes and dendritic cells (DCs) link innate and adaptive immune responses as they recognize viral antigens and induce antigen-specific T-cell activation. We investigated the effects of alcohol on antigen-presenting cell functions. Acute alcohol consumption by healthy volunteers (vodka, 2 ml/kg) resulted in significantly reduced antigen-presenting cell function of monocyte-derived DCs. Reduced allostimulatory capacity of DCs treated with alcohol in vitro correlated with decreased co-stimulatory molecule (B7.1 and B7.2) expression, as well as with reduced interleukin (IL)-12 and increased IL-10 concentrations, in mixed lymphocyte cultures. Dendritic cells recognize viral antigens in hepatitis C virus (HCV) infection, and HCV disease is accelerated in alcohol-dependent individuals. For patients with chronic HCV infection, we found reduced allostimulatory capacity of myeloid DCs. Furthermore, DC function was reduced by in vitro alcohol treatment of DCs obtained from HCV-infected patients, supporting the suggestion that viral factors and alcohol may interact to doubly suppress DC functions. We found that induction of maturation with lipopolysaccharide could not fully ameliorate the reduced DC allostimulatory capacity caused by alcohol treatment, HCV infection, or their combination. In addition, soluble factors in the supernatants obtained from mixed lymphocyte cultures containing alcohol-treated DCs or DCs obtained from HCV-infected patients could transfer inhibition of T-cell proliferation in cultures containing DCs obtained from healthy volunteers. Anti-IL-10 neutralizing antibody ameliorated the reduced mixed lymphocyte reaction containing DCs obtained from HCV-infected patients, whereas exogenous IL-12, but not anti-IL-10, treatment ameliorated the reduced T-cell proliferation induced by alcohol treatment of DCs obtained from healthy volunteers. Our results support the suggestion that both acute alcohol intake and in vitro alcohol treatment inhibit DC antigen-presenting cell function and support the hypothesis that viral factors interact with alcohol to reduce DC functions in HCV infection.
The computer generation of multinomial random variates

Abstract The generation of random variates from the multinomial distribution is often required in simulation studies involving methods for the analysis of discrete data. Although several methods have been proposed, comprehensive comparisons of the various algorithms have not been previously carried out. This paper describes seven methods for multinomial variate generation and compares them with respect to the criteria of accuracy, set-up time, simplicity of implementation, storage requirements, and generation time. Based on the results of an extensive empirical study, the Brown and Bromberg (Amer. Statist. 38, 1984) two-stage procedure is generally the fastest algorithm, but requires a complicated set-up phase and extensive storage requirements. The conditional distribution method using the modal binomial variate generator of Kemp (Commun. Statist.—Theor. Meth. 15, 1986) is shown to be a good all-purpose algorithm, in that it has wide applicability, does not require a set-up phase and extensive storage, and is reasonably competitive with the Brown—Bromberg algorithm in terms of generation time.
Biochemistry and structure of the glycan secreted by desiccation-tolerantNostoc commune (Cyanobacteria)

Filaments of the desiccation-tolerant cyanobacteriumNostoc commune are embedded within, and distributed throughout, a dense glycan sheath. Analysis of the glycan of field materials and of pure cultures ofN. commune DRH 1 through light and electron microscopy, immunogold labelling and staining with dyes, revealed changes in the pattern of differentiation in glycan micro-structure, as well as localized shifts in pH, upon rehydration of desiccated field material. A Ca/Si rich external (pellicular) layer of the glycan acts as a physical barrier to epiphytic bacteria on the surface ofN. commune colonies. A purified fraction (>12 kDa) of an aqueous extract of the glycan from desiccated field material contained glucose, N-acetylglucosamine, glucosamine, mannose, and galactosamine with ratios of 3.1∶1.4∶1∶0.1∶0.06, respectively. Lipid soluble extracts ofN. commune contained trehalose and sucrose and the levels of both became undetectable following cell rehydration. Intracellular cyanobacterial trehalase was identified using immunoblotting and its synthesis was detected upon rehydration of desiccated field cultures. Elemental analysis of glycan extracts showed a flux in the concentrations of salts in the glycan matrix following rehydration of desiccated colonies. Water-stress proteins (Wsp; most abundant proteins in glycan), a water soluble UV-A/B-absorbing pigment, the lipid-soluble UV-protective pigment scytonemin (in both its oxidized and reduced forms), as well as two unidentified cyanobacterial glycoproteins (75 kDa and 110 kDa), were found within the glycan matrix. An unidentified 68 kDa protein, the second most abundant protein in aqueous extracts of the glycan, was isolated and its N-terminal sequence was determined as AFIFGTISPNNLSGTSGNSGIVGSA. Gene bank searches with this sequence identified significant homologies (35–45%) with various carbohydrate-modifying enzymes. The role of the glycan in the desiccation tolerance ofN. commune is discussed with respect to structure/function relationships.
Very high resolution 3D surface scanning using multi-frequency phase measuring profilometry

Structured light projection is one of the most accurate non-contact methods for scanning surface topologies. The field of view of such a scan may range from millimeters to several meters. One of the most precise and robust methods of structured light is Phase Measuring Profilometry. This method utilizes a sinusoidal pattern that is laterally shifted across a surface. An image is captured at uniform intervals and the “phase” is recovered for each pixel position by correlating across the shifted patterns. In general, the more pattern shifts and the higher the spatial frequency, the more accurate the depth measurement becomes, at each pixel location. However, with a high frequency, ambiguity errors can occur, so a dual frequency approach is commonly used where a low frequency pattern is used for non-ambiguous depth, followed by high frequency pattern. The low frequency result is used to unwrap the high frequency to yield a non-ambiguous and precise phase. If the high frequency is too high, then ambiguity errors will occur. The solution is a multi-frequency method. We present experimental results for several variations of the multi-frequency approach yielding accuracies of 0.127mm standard deviation in depth with 0.92mm pixel spacing. With consumer camera mega pixel technology this equates to a 0.127mm deviation over a field of view of 2 to 3 meters. To achieve this level of accuracy also requires calibration for radial and perspective distortions. Applications for this technology include non-contact surface measurement and robotic and computer vision.
Post-divorce adaptation and the attribution of responsibility

A study was conducted to explore the possible relationship between post-divorce adjustment and the attributions divorced women give for the failure of their marriages. The study revealed that significantly more subjects who attributed their divorces to interactive rather than personal factors were more active, more socially skilled, happier, more optimistic, and less likely to blame themselves rather than outside forces for failures. The findings were also analyzed in light of whether or not subjects had initiated their divorce proceedings. The importance of making interactive attributions was discussed.
TH‐E‐214‐04: MR‐Guided Thermal Therapy Using Gold Nanoshells

MRI is increasingly being used to provide imaging‐guidance of high‐ temperature thermal therapies primarily due to its inherent sensitivity to temperature changes which make it attractive for monitoring and control, as well as multiple contrast mechanisms useful for planning, targeting and verifying therapy delivery in a single setting. These advantages have opened the door for a new generation of FDA cleared laser ablation systems which can use MRI guidance. Using compact, solid state lasers operating in the near infrared (NIR) regime along with actively cooled catheters which facilitate use of higher powers and larger lesions, interstitial laser ablation of deep seated lesions in areas such as brain, prostate, liver, kidney and bone are being investigated clinically. Goldnanoparticles (AuNP) can be designed to strongly absorb in the NIR portion of the spectrum. Even in the presence of relatively low applied power, which does not raise tissue temperatures to ablative levels, biologically relevant concentrations of AuNP aptly absorb the NIR energy generating ablative temperatures making them potent mediators of targeted laser induced thermal therapy. Because of their small size and ability to have their surface chemistry modulated for functionality, AuNP's may be designed to preferentially accumulate in a variety of diseased tissue. Additionally, unlike previous investigations using molecular dyes, these particles tend to maintain their effectiveness even at higher temperatures or laser power. Here we provide an overview of our experience using MR‐guidance and temperature imaging to investigate the potential for using AuNP as mediators for delivering highly conformal laser induced thermal therapy of soft‐tissue tumors using phantoms as well as in vivo small and large animal models. MR temperature imaging provides a means to demonstrate feasibility of these therapies in a variety of scenarios as well as monitor and control therapy delivery. In addition, temperature feedback can be used to validate computational models of AuNP mediated therapy as well. In this manner, MRI is used to both verify and shape the approach to these therapies. Educational Objectives: 1. Gain perspective on the potential role of goldnanoparticles in laser induced thermal therapies. 2. Understand the growing role of MR temperature imaging in clinical laser induced thermal therapy. 3. Understand the role of MR temperature imaging in the development and validation of goldnanoparticle mediated laser induced thermal therapies.
On boundary-hybrid finite element methods for the Laplace equation

Abstract About two decades ago, I. Babuska, J.T. Oden and J.K. Lee introduced finite element methods that calculate the normal derivative of the solution along the mesh interfaces and recover the solution via local Neumann problems. These methods for the treatment of the homogeneous Laplace equation were called ‘boundary-hybrid methods’. The approach was revisited in [12] for general symmetric and positive definite elliptic equations with homogeneous boundary conditions. The new approximation is nonconforming and lends itself well for an a posteriori error estimator for conforming finite element approximations. Numerical tests presented in [12] corroborated that the error estimates are accurate and cheap for conforming approximations. This paper provides the iterative solution methods and Galerkin discretization methods on which the numerical approximations in [12] were based.
Increasing hazard of Sprint Fidelis implantable cardioverter-defibrillator lead failure

Background The Medtronic Sprint Fidelis defibrillator lead is prone to fracture and was recalled in 2007 after 665 failures and five reported deaths. Approximately 150,000 patients at risk for sudden death in the United States have Sprint Fidelis leads. The rate of Sprint Fidelis lead failure may be increasing, and physicians are confronted with the decision to replace the lead prophylactically. Objective The purpose of this study was to determine if the hazard of Sprint Fidelis lead failure is changing and to compare its performance to other contemporary implantable cardioverter-defibrillator (ICD) leads. Methods Transvenous ICD leads implanted and followed at our two tertiary-care referral centers between January 2004 and December 2008 were included in the study. Lead failure data were entered prospectively by both centers via the Multicenter Registry. Clinical data were collected prospectively by each center and merged for the purpose of this study. Results During 5,700 implant years of follow-up (average 1.9 ± 1.3 years), 94 of 3,037 defibrillator leads failed (1.65%/year), including 72 (8.5%) of 848 Sprint Fidelis leads. The cumulative hazard of Sprint Fidelis failure was significantly greater compared to 2,189 other defibrillator leads ( P P Conclusion The hazard of Sprint Fidelis lead failure is increasing, whereas the failure rates of other defibrillator leads are low and stable. Physicians should consider these data when managing patients who have Sprint Fidelis leads.
Individualized, patient-centered application of consensus guidelines to improve the quality of breast cancer care.

Individualized, Patient-Centered Application of Consensus Guidelines to Improve the Quality of Breast Cancer Care Reshma Jagsi, MD, DPhil,* Benjamin D. Smith, MD,y Michael Sabel, MD,z and Lori Pierce, MD* *Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan; yDepartment of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas; and zDepartment of Surgery, University of Michigan, Ann Arbor, Michigan