cssi/SciSciGPT-SciSciNet huggingface dataset:
Delayed referral of venous ulcers increases resource usage.

Abstract Objective Venous insufficiency is often not readily recognized as a contributing etiology to nonhealing wounds by nonvascular surgery specialists, potentially delaying appropriate treatment to achieve wound healing and increasing healthcare costs. The objective of the present study was to understand the time and resources used before the definitive treatment of venous ulcers. Methods A single-institution retrospective medical record review of C6 patients undergoing radiofrequency saphenous and perforator vein ablation from May 2016 to January 2018 identified 56 patients with 67 diseased limbs. The numbers of inpatient, emergency department, and wound care visits and the intervals to vein ablation from the initial evaluation of the ulceration by a healthcare provider were collected. The demographics, comorbidities, previous venous interventions, wound characteristics, duplex ultrasound imaging, and available wound healing follow-up through July 2018 were assessed for all patients. Results For the 67 limbs examined, 588 total healthcare visits were performed for wound assessment before a referral to a vascular surgeon, with 413 visits at a wound care center (70% of all visits). Other specialty visits included emergency medicine (17.9% of limbs) and rheumatology (22.4% of limbs). Six patients (nine limbs) were admitted to inpatient services for treatment of their ulceration. Overall, the patients were seen an average of 8.6 ± 9.7 times for their ulcer with the wound center before determination of a contributing venous etiology and subsequent treatment. These visits translated to a median of 230 days (interquartile range, 86.5-1088 days) between the first identification of the ulcer by healthcare providers and subsequent accurate diagnosis and definitive treatment of their venous disease with radiofrequency saphenous and perforator vein ablation. After intervention, 18.64% of the limbs had healed at 1 month, 33.92% had healed at 3 months, 50% had healed at 6 months, and 82.92% had healed by 12 months. Conclusions An earlier and accurate diagnosis of the venous contribution to ulcers and subsequent appropriate treatment of venous etiologies in wound formation by a vascular venous specialist could significantly improve healing and minimize resource usage.
A survey of extant organizational and computational setups for deploying predictive models in health systems

Objective Artificial intelligence (AI) and machine learning (ML) enabled healthcare is now feasible for many health systems, yet little is known about effective strategies of system architecture and governance mechanisms for implementation. Our objective was to identify the different computational and organizational setups that early-adopter health systems have utilized to integrate AI/ML clinical decision support (AI-CDS) and scrutinize their trade-offs. Materials and methods We conducted structured interviews with health systems with AI deployment experience about their organizational and computational setups for deploying AI-CDS at point of care. Results We contacted 34 health systems and interviewed 20 healthcare sites (58% response rate). Twelve (60%) sites used the native electronic health record vendor configuration for model development and deployment, making it the most common shared infrastructure. Nine (45%) sites used alternative computational configurations which varied significantly. Organizational configurations for managing AI-CDS were distinguished by how they identified model needs, built and implemented models, and were separable into 3 major types: Decentralized translation (n = 10, 50%), IT Department led (n = 2, 10%), and AI in Healthcare (AIHC) Team (n = 8, 40%). Discussion No singular computational configuration enables all current use cases for AI-CDS. Health systems need to consider their desired applications for AI-CDS and whether investment in extending the off-the-shelf infrastructure is needed. Each organizational setup confers trade-offs for health systems planning strategies to implement AI-CDS. Conclusion Health systems will be able to use this framework to understand strengths and weaknesses of alternative organizational and computational setups when designing their strategy for artificial intelligence.
BReATHE interventions (Beating Regional Asthma Through Health Education)-an innovative approach to children's asthma care in the North East and North Cumbria, UK: an interventional study.

To objective of this project was to reduce unplanned hospital admission rates in children related to asthma to the Newcastle upon Tyne Hospitals National Health Service Trust (NUTH). Multiple educational interventions were introduced both locally and regionally including: a collection of educational materials aimed at young people and families, schools, primary care and secondary care on the website www.beatasthma.co.uk; regional training days; a nurse-led one-stop clinic; a new pathway following an acute attendance to hospital with an asthma attack; a local asthma service and cascade training for schools. The primary outcome measure was reduction in unplanned hospital admission rates in children due to asthma to the NUTH. Results showed that admission rates had been increasing at a sustained rate of approximately 30% each year in the 3 years prior to our intervention. After the Beating Regional Asthma Through Health Education interventions, unplanned admissions to NUTH reduced by 29% and this reduction has been sustained for the last 3 years. This compares with a regional increase of 10% over the same time period. In conclusion, simple but effective educational interventions resulted in a significant and sustained reduction in unplanned asthma admissions to NUTH. Further work is underway to extend the reach of these interventions into primary care and schools.
Social Protection and the Market in Latin America: The Transformation of Social Security Institutions

Social security institutions have been among the most stable post-war social programs around the world. Increasingly, however, these institutions have undergone profound transformation from public risk-pooling systems to individual market-based designs. Why has this 'privatization' occurred? Why do some governments enact more radical pension privatizations than others? This book provides a theoretical and empirical account of when and to what degree governments privatize national old-age pension systems. Quantitative cross-national analysis simulates the degree of pension privatization around the world and tests competing hypotheses to explain reform outcomes. In addition, comparative analysis of pension reforms in Argentina, Brazil, Mexico and Uruguay evaluate a causal theory of institutional change. The central argument is that pension privatization emerges from political conflict, rather than from exogenous pressures. The argument is developed around three dimensions: the double bind of globalization, contingent path-dependent processes, and the legislative politics of loss imposition.
The effect of vestibular rehabilitation on adults with bilateral vestibular hypofunction: a systematic review

Purpose :A dults with bilateral vestibular hypofunction (BVH) experience signi ficant disability. A systematic review assessed evidence for vestibular rehabilitation (VR). Number of studies :1 4 studies. Materials/methods :S earch identi fication of studies based on inclusion criteria: (a) population: adults with BVH of peripheral origin; (b) interventions: vestibular exercises, balance training, education, or sensory prosthetics; (c) comparison: single interventions or compared to another psychophysical intervention, placebo, or healthy population; (d) outcomes: based on International Classification of Functioning, Disability and Health (ICF) Body Functions and Structure, Activity, and Participation; (e) study designs: prospective and interventional, Levels of Evidence I to III per Centre of Evidence-based Medicine grading. Coding and appraisal based on ICF framework and strength of evidence synthesis. Results :F ive Level II studies and nine Level III studies: All had outcomes on gaze and postural stability,five with outcomes on gait speed and perceptions of oscillopsia and disequilibrium. Conclusions :( a) Moderate evidence strength on improved gaze and postural stability (ICF-Body Functions) following exercise- based VR; (b) Inadequate number of studies supporting benefi to f VR on ICF-Participation outcomes; (c) Sensory prosthetics in early phase of development. Clinical relevance :M oderate evidence strength in support of VR from an impairment level; clinical practice and research needed to explore interventions extending to ICF-Activity and Participation.
Tracheal Tissue Engineering

We provide a description of the structure and function of the mammalian trachea. This is followed by a discussion of medical conditions and current treatment modalities. We then provide specific examples of tissue engineering as it applies to fabricating the trachea.
The effect of acquired immunologic tolerance on the development of leukemia.

In these experiments, viable spleen cells from young, healthy AKR mice were injected intravenously into newborn C3H f /Bi mice. Acquired tolerance to normal skin and leukemic cell homografts from AKR mice was demonstrated in the C3H animals. This presence of "cellular chimerism" with lymphoid cells from a strain of mice with a high spontaneous incidence of leukemia did not result in the development of this disease in the host animals. These tolerant C3H f /Bi mice were also found not to be susceptible as adults to leukemia induction with cell free filtrates from leukemic tissues of AKR mice.
Information Poor, Information Rich: Rural America and the Internet

ABSTRACT Rural America has traditionally lagged behind urban areas in the delivery of information goods and services. Two major barriers to enhanced information access: distance and a limited number of information resources, can be negated by telecommunications networks such as the Internet. Using three common Internet telecommunications systems, the Cooperative Extension Service is examined as a developing resource of networked information for rural America.
Studies on acute leukemia and infectious mononucleosis of childhood. II. Ultrastructure of cultured lymphoblastoid cells.

Abstract The light- and electron-microscopic features of lymphoblastoid cells in long-term cultures appeared similar regardless of whether these cells were derived from bone marrows of children with leukemia or infectious mononucleosis. Most of these cells closely resembled immature cells of lymphoid origin; a few resembled plasma cells. Three strains derived from a child with leukemia and five strains derived from five children with infectious mononucleosis were studied. Several hundred cells of each strain were examined. In spite of this extensive search, leukemia-like virus particles were not found in the eight strains examined.
Studies on the energy metabolism of pig red cells. I. The limiting role of membrane permeability in glycolysis.

Abstract 1. 1. Pig red cells do not glycolyze in vitro, even though the necessary enzymes can be demonstrated in hemolysates. Although ATP levels are adequate, the cell has a very low permeability to glucose. During an 8-h incubation, ATP (2.58 ± 0.06 μM/ml erythrocytes) decreases by 50% whether glucose is present or not. 2. 2. Amphotericin B, a polyene antibiotic which interacts with membrane sterols, induces glycolysis in these cells. This is associated with an increase in permeability to glucose as well as sodium and potassium. 3. 3. ATP falls rapidly in the presence of amphotericin B. Part of this can be shown to be dependent on an increase of cell sodium with a concomitant stimulation of active transport. ATP is spared if the incubation is carried out in a medium of the same ionic composition as the cells, or if ouabain is added along with amphotericin B. 4. 4. The metabolic effects of amphotericin B are not specific for glucose. The cells can also form lactate from other common hexoses (mannose, fructose, galactose) when treated with the drug. 5. 5. It is concluded that pig cells have a capacity for significant glycolytic activity which is normally limited by their low permeability to glucose. Once an effective substrate gains admission to the cell, glycolysis ensues. If measures are taken to spare ATP, it can be readily shown that this glycolis contributes to the maintenance of energy stores. 6. 6. The substrate used by these cells for energy metabolism in vivo remains unknown. Analysis of plasma reveals to be the only sugar present in any detectable amount.
Credentialing of pharmacy technicians in the USA.

Objective This review will compare the USA and UK regarding pharmacy technicians' roles, it will summarize the current roles and responsibilities of pharmacy technicians in the USA, public perception of pharmacy technicians, pharmacy organizations' perspectives on pharmacy technician credentialing, academic programmes for pharmacy technicians, accreditation of pharmacy technician programmes, pharmacy technician certification exams and differing perspectives on the push for standardized technician training. It will conclude with observations regarding the importance of standardized pharmacy technician training. Methods Articles were identified via searches of PubMed and IPA from inception to November 2010 related to credentialing of pharmacy technicians. Search terms included pharmacy technician, pharmacy technician certification, pharmacy registration, technician education and technician requirements. Articles describing the roles and responsibilities of a technician, public perception of technicians, demographics, certification processes and the future of technician roles were included. An Internet search was also performed to identify articles in the lay press related to this topic. Key findings Providing a pharmacy technician with proper training and education is necessary for operating a successful pharmacy. In the USA, mandating a national standardized training programme is the source of the debate. Current rules and regulations regarding the training and education needed for a pharmacy technician vary from state to state in the USA. Attitudes of technicians towards standardized training may be difficult to change. Conclusion This paper provides a review of pharmacy technicians' roles and responsibilities across different pharmacy settings. Although the literature provides some insight, more studies are needed to assess the value and impact of the knowledge and skills possessed by certified pharmacy technicians with standardized training compared with technicians with site-specific or limited training.
Investigation of Social Networks and Discussions in STEM Education Communities on Twitter

With the increasing importance of STEM education and the popularity of micro blogging, it becomes important to study the nature of the social network within STEM education in order to observe how members of that community work together. A social network analysis (SNA) was conducted to examine the nature of the STEM education community and its key players on Twitter. The findings from the SNA will show: categories of the key players in this social network, to what extent a community exists on the Twitter platform, and the types of interactions that users contribute to the community, and kinds of information being discussed.
Pledge (and Hedge) Allegiance to the Company

Companies include equity in a compensation package to align the interests of management with those of shareholders. It is not uncommon for an executive who has been employed at a company for many years to accumulate a substantial dollar ownership position in the company. With a concentration of wealth in a single financial asset, the executive may want to limit his or her exposure by hedging a portion of the position through financial instruments or pledging shares as collateral for a loan. While there are many reasons why a board may want to allow an executive to hedge or pledge an equity ownership position, there are also many reasons why this may be a cause for concern. We examine these issues in detail. Can boards explain why they do or do not allow executive hedging? If an executive has hedged the equity position, why does the board continue to grant new equity and not cash? Topics, Issues and Controversies in Corporate Governance and Leadership: The Closer Look series is a collection of short case studies through which we explore topics, issues, and controversies in corporate governance. In each study, we take a targeted look at a specific issue that is relevant to the current debate on governance and explain why it is so important. Larcker and Tayan are co-authors of the book Corporate Governance Matters, and A Real Look at Real World Corporate Governance.
A study of sub-millimeter wave coupled dielectric waveguides using the GIE method

The coupling properties of coupled dielectric waveguides were evaluated by using a novel and powerful method, the GIE (generalized integral equation) method, which relies on the concept of equivalent planar polarization dipole moments to simulate the guides. Generalized impedance boundary conditions are enforced to provide a simple planar integral equation. This method can account for multiple dielectric strips on different levels. Phase constants of the different modes and coupling characteristics were calculated for several structures, such as rib waveguides and insulated image guides. >
Vortexlet models of flapping flexible wings show tuning for force production and control

Insect wings are compliant structures that experience deformations during flight. Such deformations have recently been shown to substantially affect induced flows, with appreciable consequences to flight forces. However, there are open questions related to the aerodynamic mechanisms underlying the performance benefits of wing deformation, as well as the extent to which such deformations are determined by the boundary conditions governing wing actuation together with mechanical properties of the wing itself. Here we explore aerodynamic performance parameters of compliant wings under periodic oscillations, subject to changes in phase between wing elevation and pitch, and magnitude and spatial pattern of wing flexural stiffness. We use a combination of computational structural mechanics models and a 2D computational fluid dynamics approach to ask how aerodynamic force production and control potential are affected by pitch/elevation phase and variations in wing flexural stiffness. Our results show that lift and thrust forces are highly sensitive to flexural stiffness distributions, with performance optima that lie in different phase regions. These results suggest a control strategy for both flying animals and engineering applications of micro-air vehicles.
Rheological controllability of double-ended MR dampers subjected to impact loading

The vast majorities of the applications of MR dampers have been for transportation applications-mainly shock absorbers for automobile suspensions, heavy truck seats, and racecar suspensions-where the MR device is not subjected to very high velocities. For these applications, as well as many others, although the MR device is most often subjected to relatively low velocities, the MR fluid which passes through a narrow piston gap can experience very high velocities and shear rates. Yet, there is very little known about the dynamics of MR fluids at these very high shear rates. This study will provide some of the results from an extensive experimental study that was conducted on the impact dynamics of MR dampers, at the Advanced Vehicle Dynamics Laboratory of Virginia Tech. For brevity, the results that are included in this paper are limited to those for a double-ended MR damper, which is most suitable for impact applications. For an impact velocity of 160 in/s and drop mass of 55 lb, the results indicate that the double-ended MR damper transmits relatively large forces, which are hypothesized to be due to the large size of the damper and the large amount of MR fluid that needs to be accelerated in the damper. For all of the tests on the double-ended MR damper, the fluid became controllable once the piston velocity dropped below a threshold value. The relationship between the threshold value and fluid characteristics showed that the transition to controllable tended to occur at about the same point as the transitioning of the fluid flow from turbulent to laminar.
A common 40 amino acid motif in eukaryotic RNases H1 and caulimovirus ORF VI proteins binds to duplex RNAs

Eukaryotic RNases H from Saccharomyces cerevisiae , Schizosaccharomyces pombe and Crithidia fasciculata , unlike the related Escherichia coli RNase HI, contain a non-RNase H domain with a common motif. Previously we showed that S.cerevisiae RNase H1 binds to duplex RNAs (either RNA-DNA hybrids or double-stranded RNA) through a region related to the double-stranded RNA binding motif. A very similar amino acid sequence is present in caulimovirus ORF VI proteins. The hallmark of the RNase H/caulimovirus nucleic acid binding motif is a stretch of 40 amino acids with 11 highly conserved residues, seven of which are aromatic. Point mutations, insertions and deletions indicated that integrity of the motif is important for binding. However, additional amino acids are required because a minimal peptide containing the motif was disordered in solution and failed to bind to duplex RNAs, whereas a longer protein bound well. Schizosaccharomyces pombe RNase H1 also bound to duplex RNAs, as did proteins in which the S.cerevisiae RNase H1 binding motif was replaced by either the C.fasciculata or by the cauliflower mosaic virus ORF VI sequence. The similarity between the RNase H and the caulimovirus domain suggest a common interaction with duplex RNAs of these two different groups of proteins.
Case report 345

This 88-year-old man was admitted to Johns Hopkins Hospital for evaluation of a mass in the right hand, which he first noted when he began to use a cane. The patient complained of weakness of the right hand, pain at night and persistent numbness of the right thumb, index and middle fingers. Physical examination demonstrated thenar atrophy and a minimally tender 2 x 3 cm mobile mass at the base of the thenar eminence. The overlying skin appeared normal; no swelling, erythema or fluctuation was noted. Sensation in the right thumb, index finger and radial aspect of the middle finger was decreased to soft touch. The thumb-to-fifth finger apposition was 3/5 on the right and s/5 on the left.
A Kinetic Study of the SCWO of a Sulfonated Lignin Waste Stream

The kinetics of the supercritical water oxidation (SCWO) of a sulfonated lignin waste from an industrial source was investigated using a semi-batch, continuous-flow tube reactor. Experiments were carried out at reduced pressures from 0.9 to 1.4 and reduced temperatures from 0.9 to 1.2. In addition, the feed concentration, excess oxidant, flow rate in the reactor, and reactor length were varied to obtain a wide range of experimental residence times and conversions. The residence time and conversion data were used to calculate the reaction orders and Arrhenius parameters. The kinetic model was validated by comparison of the predicted to the experimental conversions. Overall, the results of the kinetic analysis were found to compare very favorably with those from model compound studies in the literature. Based on these results, it was concluded that the overall rate-limiting step was the oxidation of the sufonated lignin ring C−C bonds.
Mariner 6 and mariner 7 ultraviolet spectrometer: in-flight measurements of simulated jupiter atmosphere.

In-flight UV spectrometric measurements of simulated Jupiter atmosphere, using sunlit gas mixture released from Mariner spacecraft in interplanetary space
Can epidural catheters penetrate dura mater? An anatomical study

Summary A study using postmortem dura mater and arachnoid mater showed that catheter perforation of dura did not occur. In contrast, perforation of arachnoid proved easy.
Formal verification of dependable distributed protocols

Abstract Dependable distributed systems often employ a hierarchy of protocols to provide timely and reliable services. Such protocols have both dependability and real-time attributes, and the verification of such composite services is a problem of growing complexity even when using formal approaches. Our intention in this paper is to exploit the modular design aspects appearing in most dependable distributed protocols to provide formal level of assurance for their correctness. We highlight the capability of our approach through a case study in formal modular specification and tool-assisted verification of a timestamp-based checkpointing protocol. Furthermore, during the process of verification, insights gained in such a stack of protocols have assisted in validating some additional properties those dealing with failure recovery.
The Parameter Inference for Nearly Nonstationary Time Series

Abstract A first-order autoregressive (AR) time series Yt = βY t-1 + et is said to be nearly nonstationary if β is close to 1. For a nearly nonstationary AR(1) model, it is shown that the limiting distribution of the least squares estimate of β obtained by Chan and Wei (1987) can be expressed as a functional of the Ornstein-Uhlenbeck process. This alternative expression provides a simple and efficient means to tabulate the percentiles of the limiting distribution that furnishes a useful procedure to test for near nonstationarity. Based on the eigenvalue-eigenfunction consideration, it is shown that the Ornstein-Uhlenbeck formulation possesses an infinite series expansion that extends the result of Dickey and Fuller (1979) to the nearly nonstationary model. Numerical calculations based on different representations of the limiting distribution are performed and compared. It is found that the Ornstein-Uhlenbeck expression provides a better algorithm for tabulating the percentiles. Applications to other time ...
Gas exchange characteristics of leaves of four species of grain amaranth

Abstract Four species of the C4 genus Amaranthus, A. cruentus, A. caudatus, A. hypochondriacus and A. hybridus , were grown at Salt Lake City, Utah for the determination of gas exchange characteristics of recently matured leaves. The response of CO 2 assimilation to leaf temperature, measured at high quantum flux, was very similar in all species, each exhibiting a temperature optimum of approximately 37°C. Above about 40°C, all species showed high temperature inhibition, manifested as an irrversible time-dependent decline in CO 2 assimilation. All four exhibited high rates of net CO 2 assimilation exceeding 40 μmol m −2 s −1 at quantum fluxes of 2.0 mmol m −2 s −1 , but none was completely light-saturated at such intensities. Leaf conductance to water vapor declined with decreasing quantum flux in all species, but less rapidly than assimilation, resulting in increasing values of internal CO 2 concentration ( c i ). Quantum yield values in three species ( x =0.048±0.003 mol( CO 2 /mol(photons))) were similar to those reported previously for NAD-malic enzyme type C4 dicots, but leaves of A. hybridus , which were deep purple in color, exhibited a lower quantum yield, presumably due to light absorption by betacyanin pigments not involved in photosynthesis. All four species had net photosynthesis versus c i responses typical of C4 species, with a steep initial linear response to c i followed by a fairly abrupt transition to saturation in the region of 100–150 μl l −1 . Under near-optimal measurement conditions and high quantum flux, all species maintained c i values close to the region at which saturation was reached ( x =148±17 μ l l −1 ). Data pooled acrossspecies relating net photosynthesis measured at 2.0 mmol m −2 s −1 quantum flux and 35°C to Kjeldahl nitrogen content revealed a linear relationship, the slope of which was not significantly different ( P =0.05) from those reported in two otudies employing C4 species.
Location control of electron donors and acceptors in photoinduced charge separation across surfactant interfaces

Abstract The efficiency of photoinduced charge separation across surfactant interfaces of micelles and vesicles depends in part on the location of electron donors and acceptors relative to the interface. Achievement and assessment of control of such location by the addition of pendant alkyl chains to donors and acceptors are reviewed. The net photo-ionization efficiency can be measured by electron spin resonance of radical ions in frozen surfactant solutions. Assessment of relative locations of radical ions with respect to a surfactant interface has been achieved by analysis of electron spin-echo modulation with deuterated water at the interface. Alkylmethylviologen electron acceptors are shown to be particularly useful for location control of photo-ionization efficiency in vesicles and less so in micelles. Electron donors investigated for location control include alkylated ruthenium tris(bipyridyl) species and alkylphenothiazine sulphonate derivatives. Photoinduced conversion of alkylmethylviologen radic...
The effect of wavelength on the polymerization of multi(meth)acrylates with disulfide/benzilketal combinations

Abstract As an alternative to asymmetric iniferters like XDT ( p -xylylene bis( N , N -diethyldithiocarbamate), the use of DMPA (2,2-dimethoxy-2-phenylacetophenone) in combination with TED (tetraethylthiuram disulfide) has been proposed as a means of studying living radical polymerizations and creating crosslinked polymers without trapped radicals. This dual initiator system ideally could imitate XDT. The DMPA would photocleave and initiate the reaction via carbon radicals while the TED would photocleave and terminate via dithiocarbamyl (DTC) radicals. In this contribution, we report that for the case of TED and DMPA photoinitiated systems, the nature of the living polymerization and the polymerization kinetics are dependent on the wavelength of light used. Kinetic studies of TEGDMA (triethylene glycol dimethacrylate) photocured with monochromatic light at wavelengths 290, 310, 324, and 365 nm were performed using differential scanning calorimetry. TED was added in incremental amounts to determine its effect on the polymerization as a function of wavelength and concentration. The results suggest that termination via DTC radicals becomes more prominent as the irradiating wavelength is increased. A model was developed that incorporates three modes of chain breaking, where carbon–carbon termination, carbon-DTC termination, and chain transfer to TED are all referred to as chain breaking reactions. The model fit the data well after the maximum rate of polymerization. Furthermore, the model predicts that termination involving TED and its derivatives dominates over carbon radical–carbon radical termination when the ratio of TED:DMPA is 1:2 or higher in TED. Therefore, TED:DMPA combinations can be used as an alternative to conventional iniferters as long as a sufficient amount of TED has been added so that carbon–sulfur chain breaking reactions dominate over traditional termination. Infrared analysis of several samples proved that TED:DMPA combinations greater than 1:2 can prevent trapped carbon radicals from persisting in polymer networks after cure.
Programmed cell death 1 (PD-1) and its ligand PD-L1 are required for allograft tolerance

Programmed cell death-1 (PD-1, CD279) and its widely expressed, inducible ligand, PD-L1 (CD274), together dampen T cell activation, but whether they are essential for allograft tolerance is unknown. We show, using gene-deficient mice and blocking mAbs in wild-type mice, that costimulation blockade is ineffectual in PD-1(-/-) or PD-L1(-/-) allograft recipients, or in wild-type allograft recipients treated with anti-PD-1 or anti-PD-L1 mAb. Alloreactive PD-1(-/-) CD4 and CD8 T cells had enhanced proliferation and cytokine production compared to wild-type controls, and anergy could not be induced in PD-1-deficient CD4 T cells. We conclude that without inhibitory signals from PD-1 ligation, alloantigen-induced T cell proliferation and expansion cannot be regulated by costimulation blockade, and peripheral tolerance induction cannot occur.
3D face identification: experiments towards a large gallery

3D face recognition technologies, with a computation time of a few seconds, perform well for person verification. However, current 3D face recognition approaches are too slow for person identification, even for a watch list of only a few hundred face models. By transforming scanned 3D faces into a canonical face format, storage size is greatly compressed and standard feature extraction is enabled: combining these advantages allows a probe scan to be matched to hundreds or thousands of gallery scans in a few seconds on a commodity computer. We report several experiments that extract a sparse feature representation from the canonical 3D face surface and then perform recognition of a probe face based on the sparse features. We expect to have a trade off between algorithm speed and recognition performance. The best results achieved so far are a rank-1 recognition rate of 98.2% and a speed of 1900 face matches per second. Extrapolating these results suggests that multistage systems could achieve comparable or better recognition rates over large galleries within 5 seconds of compute time.
Why Stress Is Bad for Your Brain

Several recent studies of humans correlate stress with atrophy of the hippocampus, an area of the brain required for memory and cognition. In his Perspective, Sapolsky argues that the underlying causal agent may be glucocorticoids secreted in abnormally high amounts under stressful conditions.
Latent hepatitis B is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis C

Latent hepatitis B is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis C
Feedback can at most double Gaussian multiple access channel capacity (Corresp.)

The converse for the discrete memoryless multiple access channel is generalized and is used to derive strong bounds on the total capacity (sum of the rates of all the senders) of an m -user Gaussian multiple access channel in terms of the input covariance matrix. These bounds are used to show that the total capacity of the channel with feedback is less than twice the total capacity without feedback. The converse for the general multiple access channel is also used to show that for any m -user multiple access channel, feedback cannot increase the total capacity by more than a factor of m .
Use of digital images to differentiate reactions of collections of yellow starthistle (Centaurea solstitialis) to infection by Puccinia jaceae

Yellow starthistle (YST) (Centaurea solstitialis) is an invasive weed in the USA and a target of classical biological control. However, the precise geographical origin(s) of YST in the USA is not known. This study was conducted to learn whether the origin(s) of YST in California, USA could be determined on the basis of digital image analysis (DIA) of YST reactions to isolates of the rust Puccinia jaceae. One trial was conducted with two isolates of P. jaceae and another trial with only one of these isolates. Six different YST collections were tested. The DIA consistently detected and measured rust pustules on YST leaves. Compared to visual assessment, DIA was a fair predictor of the number of rust pustules per leaf. There were no differences between isolates of P. jaceae in reactions of different YST collections in the first trial. Differences in plant reactions between trials were predominately due to more disease incidence and severity in the second trial, which was probably from the greater amount of inoculum. Based on analyses of variance and canonical discriminative analyses, YST from California appeared most closely related to the YST collection from Erzurum, Turkey. In examination of squared Mahalanobis distances, all collections, except the collection from Turkey, were significantly distant from the California collection in both trials. More studies are necessary to determine the precise area(s) of origin (within Turkey and neighboring countries) of YST in the USA. Digital image analysis of rust reactions can be a powerful tool to do this.
Steady-State of The SLAW Mobility Model

Movement patterns of mobile nodes significantly affect the performance of a Mobile Ad hoc Network (MANET) routing protocol. Thus, it is essential that the mobility traces generated by a mobility model closely match the trace data collected from experiments. In addition, the probability distribution of mobile nodes (over the simulation area) varies with time before it comes to a steady-state. In other words, distribution of mobile nodes in steady-state is independent of their initial position. If traces generated by a mobility model are used before its steady-state is reached, this variability in distribution may lead to misleading results, called initialization bias. Thus, for credible MANET simulations, it is required that a mobility model used (1) is realistic (i.e., its mobility traces closely match the experimental data) and (2) starts in a steady- state (i.e., there is no initialization bias). In this work, we analyze a recently published realistic mobility model, called SLAW. The SLAW mobility model is based on real GPS traces collected from five outdoor sites. Previous work with SLAW is done by discarding the first few hours of simulation time; however, discarding initial data does not guarantee that the model has reached its steady-state. Thus, the main contribution of our work is that we provide methods for sampling from the steady- state distributions of mobile nodes' locations and pause- times. Sampling from the steady-state distributions allows the SLAW mobility model to start in a steady-state and thus, avoids initialization bias related to the mobility model.
Effects of Playing Videogames on Children's Aggressive and Other Behaviors

Noting the pervasiveness of videogames in American culture, the authors set out to examine the effects that playing videogames has on children. Thirty-one children were matched on sex, randomly assigned to play either a violent (karate) videogame or a nonviolent (jungle vine swinging) videogame, and then observed during free play. The main results were that the children who had played the jungle swing videogame later played more with a jungle swing toy and that the children who played the violent videogame later showed more aggression. The authors interpreted the findings as an indication that young children who play videogames later tend to act similarly to how their videogame character acted.
Comparison of Naive Sixth-Grade Children With Trained Professionals in the Use of an Automated External Defibrillator

Background—Survival after out-of-hospital cardiac arrest (OHCA) is strongly influenced by time to defibrillation. Wider availability of automated external defibrillators (AEDs) may decrease response times but only with increased lay use. Consequently, this study endeavored to improve our understanding of AED use in naive users by measuring times to shock and appropriateness of pad location. We chose sixth-grade students to simulate an extreme circumstance of unfamiliarity with the problem of OHCA and defibrillation. The children’s AED use was then compared with that of professionals. Methods and Results—With the use of a mock cardiac arrest scenario, AED use by 15 children was compared with that of 22 emergency medical technicians (EMTs) or paramedics. The primary end point was time from entry onto the cardiac arrest scene to delivery of the shock into simulated ventricular fibrillation. The secondary end point was appropriateness of pad placement. All subject performances were videotaped to assess safety...
Predictors and outcomes of scleroderma renal crisis: The high-dose versus low-dose D-penicillamine in early diffuse systemic sclerosis trial

Objective The reported frequency of scleroderma M01-R renal crisis (SRC) in diffuse systemic sclerosis (SSc; scleroderma) is 15–20%. Early use of angiotensin-converting enzyme (ACE) inhibitors has markedly improved outcome. The present analysis reexamines the prognostic factors for and outcome of SRC in a prospective cohort of patients with early diffuse SSc. Methods We retrospectively evaluated the cohort of SSc patients who participated in the High-Dose Versus Low-Dose D-Penicillamine in Early Diffuse SSc trial. Patients with diffuse cutaneous scleroderma were enrolled if their disease duration was <18 months. Because the trial failed to show a difference between treatment groups, the data were pooled. Results One hundred thirty-four SSc patients entered the observation period a mean ± SD of 0.8 ± 0.3 years after onset of SSc. SRC occurred in 18 patients a mean ± SD of 0.9 ± 1.1 years after entry. During a mean ± SD 4.0 ± 1.1 years of followup after entry, 9 of the 18 patients died (mean ± SD 0.6 ± 0.9 years after SRC onset). Baseline characteristics that predicted SRC included a modified Rodnan skin thickness score of ≥20 (P < 0.01), enlarged cardiac silhouette on radiograph (P = 0.04), large joint contractures (wrist, elbow, knee) (P = 0.008), and prednisone use at entry (P = 0.01). Baseline characteristics that did not predict SRC included age, sex, race, Health Assessment Questionnaire score, fist closure, handspread, lung involvement, muscle weakness, erythrocyte sedimentation rate, and platelet count. In 5 of 10 subjects for whom at least 2 sequential skin scores were available, skin scores increased significantly (P = 0.012) in the 6 months before onset of SRC. Conclusion SRC occurred in 13% of patients soon (mean 11 months) after entry into the cohort. Predictors of SRC identified in this study included higher than average skin score, prednisone use at study entry, large joint contractures, and heart enlargement. Our data suggest, however, that low-dose prednisone alone was not associated with the onset of SRC, except in the appropriate clinical setting. Although ACE inhibitors and dialysis are now readily available, SRC continues to be associated with poor survival (in this study, 50% of patients with SRC died).
APX-hardness of domination problems in circle graphs

We show that the problem of finding a minimum dominating set in a circle graph is APX-hard: there is a constant δ > 0 such that there is no (1 + δ)-approximation algorithm for the minimum dominating set problem on circle graphs unless P = NP. Hence a PTAS for this problem seems unlikely. This hardness result complements the (2 + e)-approximation algorithm for the problem [M. Damian, S.V. Pemmaraju, A (2 + e)-approximation scheme for minimum domination on circle graphs, J. Algorithms 42 (2) (2002) 255-276].
Redemocratization, Electoral Engineering, and Party Strategies in Chile, 1989-1995

Can the deliberate manipulation of electoral rules help achieve political moderation and stability? An unusual electoral system in Chile provides a dramatic, albeit controversial, instance of political engineering. The binominal system, promulgated by the outgoing Pinochet government, mandates two-member districts for the upper and lower legislative chambers. Binominal electoral rules occupy a middle ground between majoritarian and PR systems. In Chile, the binominal system has provided incentives to form broad alliances, and has encouraged centripetal political competition, without generating extreme disproportionality between votes and seats. Using Lijphart's index, disproportionality was 5.80 in 1989 and 5.75 in 1993—higher than most PR systems, but lower than most plurality systems.
Simultaneous near-infrared diffusive light and ultrasound imaging

We have constructed a near-real-time combined imager suitable for simultaneous ultrasound and near-infrared diffusive light imaging and coregistration. The imager consists of a combined hand-held probe and the associated electronics for data acquisition. A two-dimensional ultrasound array is deployed at the center of the combined probe, and 12 dual-wavelength laser source fibers (780 and 830 nm) and 8 optical detector fibers are deployed at the periphery. We have experimentally evaluated the effects of missing optical sources in the middle of the combined probe on the accuracy of the reconstructed optical absorption coefficient and assessed the improvements of a reconstructed absorption coefficient with the guidance of the coregistered ultrasound. The results have shown that, when the central ultrasound array area is in the neighborhood of 2 cm × 2 cm, which corresponds to the size of most commercial ultrasound transducers, the optical imaging is not affected. The results have also shown that the iterative inversion algorithm converges quickly with the guidance of a priori three-dimensional target distribution, and only one iteration is needed to reconstruct an accurate optical absorption coefficient.
Ford Motor Company and the Firestone tyre recall

This paper was prepared as the basis for a class discussion rather than to illustrate either effective or ineffective handling of an administrative situation. It may be appropriate for public affairs, business and public policy, and/or crisis management courses at the undergraduate or graduate level. In conjunction with this case, it may be useful to use the framework for crisis management developed by Dr Ian I. Mitroff, the Harold Quinton Distinguished Professor of Business Policy at the Marshall School of Business, University of Southern California. This best practice model is discussed in ‘Managing Crises Before They Happen’, which Mitroff published in 2001 with Gus Anagnos, Vice President of Comprehensive Crisis Management. This case leads the audience through the Ford–Firestone tyre crisis from 1997—when Ford began to learn of a problem with Firestone tyres on its popular Explorer sport-utility vehicle—up until the summer of 2001, just after Ford recalled 13 million Firestone tyres and the National Highway Transportation and Safety Administration cleared Ford of further investigation into potential defects in the Explorer. The case addresses potential causes of the tyre problem, how Ford handled the crisis from a corporate public affairs perspective and, tangentially, how Firestone handled the issue. Copyright © 2003 Henry Stewart Publications
Methoctramine, a cardioselective muscarinic cholinergic antagonist, prevents fentanyl‐induced bradycardia in the dog

A controlled study examining the effects of the cardioselective muscarinic cholinergic antagonist methoctramine on fentanyl-induced bradycardia was performed in six dogs. Five doses of methoctramine (6, 10, 20, 30 and 60 micrograms/kg) followed by fentanyl (20 micrograms/kg) were administered randomly on separate days. Fentanyl caused a significant reduction in heart rate from baseline values. Moreover, fentanyl produced a variety of arrhythmogenic actions indicative of vagal hyperactivity, including sinus bradycardia, second-degree atrioventricular block and ventricular and supraventricular escape beats. Administration of methoctramine 5 min before fentanyl injection prevented the bradycardic effects of fentanyl in a dose-dependent manner, with high doses of methoctramine causing sinus tachycardia. Using regression analysis, the dose of methoctramine necessary to prevent fentanyl-induced bradyarrhythmias without causing tachycardia was calculated as 14.4 micrograms/kg. The study confirmed that fentanyl administration in the conscious dog causes profound bradycardia with bradyarrhythmias. The cardioselective muscarinic antagonist agent methoctramine prevented the bradycardic effects of fentanyl.