cssi/SciSciGPT-SciSciNet huggingface dataset:
Learning without the Phase: Regularized PhaseMax Achieves Optimal Sample Complexity

The problem of estimating an unknown signal, $\mathbf x_0\in \mathbb R^n$, from a vector $\mathbf y\in \mathbb R^m$ consisting of $m$ magnitude-only measurements of the form $y_i=|\mathbf a_i\mathbf x_0|$, where $\mathbf a_i$'s are the rows of a known measurement matrix $\mathbf A$ is a classical problem known as phase retrieval. This problem arises when measuring the phase is costly or altogether infeasible. In many applications in machine learning, signal processing, statistics, etc., the underlying signal has certain structure (sparse, low-rank, finite alphabet, etc.), opening of up the possibility of recovering $\mathbf x_0$ from a number of measurements smaller than the ambient dimension, i.e., $m<n$. Ideally, one would like to recover the signal from a number of phaseless measurements that is on the order of the "degrees of freedom" of the structured $\mathbf x_0$. To this end, inspired by the PhaseMax algorithm, we formulate a convex optimization problem, where the objective function relies on an initial estimate of the true signal and also includes an additive regularization term to encourage structure. The new formulation is referred to as {\textbf{regularized PhaseMax}}. We analyze the performance of regularized PhaseMax to find the minimum number of phaseless measurements required for perfect signal recovery. The results are asymptotic and are in terms of the geometrical properties (such as the Gaussian width) of certain convex cones. When the measurement matrix has i.i.d. Gaussian entries, we show that our proposed method is indeed order-wise optimal, allowing perfect recovery from a number of phaseless measurements that is only a constant factor away from the degrees of freedom. We explicitly compute this constant factor, in terms of the quality of the initial estimate, by deriving the exact phase transition. The theory well matches empirical results from numerical simulations.
Nurse perceptions of the impact of demands and resources on wellbeing, satisfaction and commitment

This paper explores the relationship between three types of organizational resources (job control, social support and organizational justice) and the impact of job demands on nurse's health and att...
AN APPROACH TO FIELD TRAINING

The field training program of the Department of Public Health, Indiana University School of Medicine, provides the student with ten weeks of actual inspection work on an individual basis with quali...
‘SCALD-ED’ Block: Superficial Cutaneous Anesthesia in a Lateral Leg Distribution within the Emergency Department – A Case Series

Abstract Background In the midst of a nationwide opioid epidemic, focus has been placed on identifying and utilizing safe, effective opioid-free analgesic alternatives. Lower-extremity peripheral nerve blockades are common and often involve both motor and sensory anesthesia, resulting in leg weakness and ambulatory difficulty. The aim of this case report is to describe an ultrasound-guided peripheral nerve block technique (superficial cutaneous anesthesia in a lateral (leg) distribution within the emergency department [‘SCALD-ED’ block]) that provides motor-sparing, purely sensory anesthesia after a superficial injury to the lateral leg in patients presenting to the emergency department. Discussion Two separate patients presenting with lateral leg pain after superficial injury (burn, cellulitis) reported continued breakthrough pain despite a standard analgesic modality of combination acetaminophen and ibuprofen. With the patient placed in prone position for ultrasound-guided access to lower-extremity nerve branches, the lateral sural cutaneous nerve (LSCN) was identified by tracing its pathway from the proximal sciatic nerve to the common peroneal (fibular) nerve to the superficial peroneal (fibular) nerve. Five mL of lidocaine (1%, with epinephrine) was injected along the superficial LSCN route for anesthetic blockade. Temporal assessments of anesthetic effect and pain improvement, and monitoring of motor or ambulatory impairment were conducted at regular intervals to assess the efficacy and feasibility of the blockade. Regional anesthesia along the LSCN sensory distribution was experienced at 7–9 min post blockade. Peak analgesic effect was experienced at 25–29 min. The duration of anesthesia was 120–150 min. A negligible amount of delayed sensory anesthesia was noted along the distal sural nerve distribution. No motor deficit, ambulatory difficulty, or adverse effects were experienced in either patient post blockade. Conclusion The LSCN is an identifiable target under ultrasound guidance, susceptible to localized, purely sensory blockade of pain from superficial cutaneous lateral leg injuries.
Modules for the Technical Skills Section of the OSCE Component of the American Board of Anesthesiology APPLIED Examination.

Introduction To assess communication and professionalism, as well as technical skills related to patient care, the American Board of Anesthesiology (ABA) has begun administering an Objective Struct...
Synthesis of 2-chloro-5,7-dihydro-6 H -pyrrolo[2,3- d ]pyrimidin-6-one

Abstract 1,3-Dihydro-2H-indol-2-ones (oxindoles) and 1,3-dihydro-2H-pyrrolopyridin-2-ones (azaoxindoles) are useful scaffolds that have been explored for various pharmaceutical uses. Herein we report the synthesis of 2-chloro-5,7-dihydro-6H-pyrrolo[2,3-d]pyrimidin-6-one ( 5 ) and its derivatives, and the application of 5,7-dihydro-6H-pyrrolo[2,3-d]pyrimidin-6-ones (diazaoxindoles) as novel scaffold to kinase research areas.
Cache Replacement Policies

Abstract This book summarizes the landscape of cache replacement policies for CPU data caches. The emphasis is on algorithmic issues, so the authors start by defining a taxonomy that places previou...
Reply to Comment on “Should Organic Chemistry Be Taught as Science?”

This is a response to the Comment on “Should Organic Chemistry Be Taught as Science?”, which adopts the premise that organic chemistry, as experienced by most undergraduates, is more akin to an alg...
Finding Faith in Foreign Policy: Religion and American Diplomacy in a Post-Secular World: By Gregorio Bettiza. New York: Oxford University Press, 2019, 336 pp., $74.00 (Hardback), ISBN 9780190949464

Although the ‘return of religion’ to the field of international relations has been underway for many years, there are still few intensive examinations of how religious actors, values and considerat...
Update on anti-inflammation mechanism of ketogenic diet

The ketogenic diet (KD) is an effective treatment for refractory epilepsy, including some inflammation-induced epileptic encephalopathies, and the mechanism of it is complicated.KD, through multiple targets, plays the role to inhibit pathogens, control inflammation and regulate immune function.In experiments, KD provides an anti-inflammatory effect in some rat models of fever.It has been shown that, KD decreases peripheral edema, attenuates thermal nociception and reduce arachidomic acid level in circulation.KD blocks Nod-like receptor protein 3(NLRP3), nuclear factor-kappa B(NF-κB), oxygen free radicals, and improves Peroxisome proliferator-actived Receptor(PPAR)γ level, to reach the effect of anti-inflammatory.This review focuses on ketogenic diet anti-inflammatory mechanism and the recent advances in clinical application. Key words: Ketogenic diet; Inflammation; Nervous system
Hybrid analysis reveals how DNA sequence governs genomic location and DNA contacts of bacterial chromatin H-NS filaments

Gene silencing in bacteria is mediated by chromatin proteins, of which Escherichia coli H-NS is a paradigmatic example. H-NS forms multimeric nucleoprotein filaments with either one or two DNA duplexes, but the structures of these linear or bridged filaments remains unknown. Neither the determinants of H-NS genomic distribution nor the arrangements of H-NS DNA binding domains (DBDs) in linear or bridged filaments are currently defined. To address these questions, which are central to understanding gene silencing in bacteria, we developed a hybrid approach that combines a new method for in vitro chromatin reconstitution and mapping (Nitro-seq), ChIP-seq, nuclease-tagged DBDs to map DNA contacts, {middle dot}OH footprinting, molecular dynamics, and robust bioinformatic analyses. We find that DNA sequence principally governs genomic location of all filament types with indistinguishable sequence specificity, that DBD-DNA contacts vary in orientation and precise position with [~]10-bp spacing, and that unchanging contacts in linear and bridged filaments support a hemi-sequestration model of linear-to-bridged filament switching.
Intelligent welding system technologies: State-of-the-art review and perspectives

Abstract Welding systems are being transformed by the advent of modern information technologies such as the internet of things, big data, artificial intelligence, cloud computing, and intelligent manufacturing. Intelligent welding systems (IWS), making use of these technologies, are drawing attention from academic and industrial communities. Intelligent welding is the use of computers to mimic, strengthen, and/or replace human operators in sensing, learning, decision-making, monitoring and control, etc. This is accomplished by integrating the advantages of humans and physical systems into intelligent cyber systems. While intelligent welding has found pilot applications in industry, a systematic analysis of its components, applications, and future directions will help provide a unified definition of intelligent welding systems. This paper examines fundamental components and techniques necessary to make welding systems intelligent, including sensing and signal processing, feature extraction and selection, modeling, decision-making, and learning. Emerging technologies and their application potential to IWS will also be surveyed, including Industry 4.0, cyber-physical system (CPS), digital twins, etc. Typical applications in IWS will be surveyed, including weld design, task sequencing, robot path planning, robot programming, process monitoring and diagnosis, prediction, process control, quality inspection and assessment, human-robot collaboration, and virtual welding. Finally, conclusions and suggestions for future development will be proposed. This review is intended to provide a reference of the state-of-the-art for those seeking to introduce intelligent welding capabilities as they modernize their traditional welding stations, systems, and factories.
What’s your angle? Analyzing angled parking via satellite imagery to aid bike-network planning:

U.S. cities prioritize the storage of automobiles over the safe movement of bicycles. While this generally occurs by allocating street curbs for car parking instead of bike lanes, the privileging o...
Small intestinal immunopathology and GI-associated antibody formation in hereditary alpha-tryptasemia.

Background Hereditary alpha-tryptasemia (HαT) is characterized by elevated basal serum tryptase due to increased copies of the TPSAB1 gene. Individuals with HαT frequently present with multisystem complaints, including anaphylaxis and seemingly functional gastrointestinal (GI) symptoms. Objective We sought to determine the prevalence of HαT in an irritable bowel syndrome cohort and associated immunologic characteristics that may distinguish patients with HαT from patients without HαT. Methods Tryptase genotyping by droplet digital PCR, flow cytometry, cytometry by time-of-flight, immunohistochemistry, and other molecular biology techniques was used. Results HαT prevalence in a large irritable bowel syndrome cohort was 5% (N = 8/158). Immunophenotyping of HαT PBMCs (N ≥ 27) revealed increased total and class-switched memory B cells. In the small bowel, expansion of tissue mast cells with expression of CD203c, HLA-DR, and FceRI, higher intestinal epithelial cell pyroptosis, and increased class-switched memory B cells were observed. IgG profiles in sera from individuals with HαT (N = 21) significantly differed from those in individuals with quiescent Crohn disease (N = 20) and non-HαT controls (N = 19), with increased antibodies directed against GI-associated proteins identified in individuals with HαT. Conclusions Increased mast cell number and intestinal epithelial cell pyroptosis in the small intestine, and class-switched memory B cells in both the gut and peripheral blood associated with IgG reactive to GI-related proteins, distinguish HαT from functional GI disease. These innate and adaptive immunologic findings identified in association with HαT are suggestive of subclinical intestinal inflammation in symptomatic individuals.
The Flip Side of the Coin: Potential Hazards Associated with Standardization in Healthcare.

Healthcare has a lengthy history of quality improvement efforts. Perhaps due to the success of standardization methods in fields such as manufacturing and aviation, similar approaches are often proposed in healthcare quality improvement initiatives. However, fundamental differences can make the translation to use in healthcare challenging. In manufacturing, the outcome is typically a product with a certain range of tolerances; in healthcare, the goal is to maintain or restore a biological system to some desired state. In addition, people, an inextricable part of the healthcare system, are generally more complex and inherently variable than other components of a system. Patients, providers, and more all have unique needs and capabilities that must be accounted for during systems design, making standardization efforts different than in other industries. This paper discusses how different types of standardization may introduce hazards and opportunity costs as they interact with various elements of a healthcare system.
Regulation of the nicotinic acetylcholine receptor by serine and tyrosine protein kinases.

Neurotransmitter receptors play a central role in the process of signal transduction across synapses between neurons. Neurotransmitters released from the presynaptic neuron diffuse across the synaptic cleft and bind to neurotransmitter receptors in the membrane of the postsynaptic neuron. The neurotransmitter receptors then transduce this signal across the postsynaptic membrane either by directly activating ion channels or by regulating the level of intracellular second messengers in the postsynaptic neuron. Because of the essential role of neurotransmitter receptors in synaptic transmission, the short and long term modulation of neurotransmitter receptor function could be an extremely effective mechanism for the regulation of synaptic plasticity. What are the molecular mechanisms that may be involved in the modulation of neurotransmitter receptor function? Studies on the regulation of cellular metabolism over the past four decades have shown that protein phosphorylation is the primary mechanisms in the regulation of almost all cellular processes (Edelman et al, 1987, Nairn et al, 1985, Hunter et al, 1985).
A numerical dissipation rate and viscosity in flow simulations with realistic geometry using low-order compressible Navier–Stokes solvers

Abstract Recently it has become increasingly clear that the role of numerical dissipation, originating from the discretization of governing equations of fluid dynamics, rarely can be ignored regardless of the formal order of accuracy of a numerical scheme used in either explicit or implicit Large Eddy Simulations (LES). The numerical dissipation inhibits the predictive capabilities of LES whenever it is of the same order of magnitude or larger than the sub-grid-scale (SGS) dissipation. The need to estimate the numerical dissipation is most pressing for low-order methods employed by commercial CFD codes. Following the recent work of Schranner et al. (2015) the equations and procedure for estimating the numerical dissipation rate and the numerical viscosity in a commercial code are presented. The method allows to compute the numerical dissipation rate and numerical viscosity in the physical space for arbitrary sub-domains in a self-consistent way, using only information provided by the code in question. The procedure has been previously tested for a three-dimensional Taylor–Green vortex flow in a simple cubic domain and compared with benchmark results obtained using an accurate, incompressible spectral solver. In the present work the procedure is applied for the first time to a realistic flow configuration, specifically to a laminar separation bubble flow over a NACA 0012 airfoil at Ma = 0.4 and Re = 50 , 000 . The method appears to be quite robust and its application reveals that for the code and the flow in question the numerical dissipation can be significantly larger than the viscous dissipation or the dissipation of the classical Smagorinsky SGS model.
The check-pointed and error-recoverable MPI JAVA library of agent teamwork grid computing middleware

We are implementing a fault-tolerant mpiJava API on top of the AgentTeamwork grid-computing middleware system. Our mpiJava implementation consists of the mpiJava API, the GridTcp socket library, and the user program wrapper, each providing a user with the standard mpiJava functions, facilitating message-recording/error-recovering socket connections, and monitoring a user process. This paper presents the application framework, mpiJava implementation, and communication performance in AgentTeamwork.
A traveling salesman objective function that works

An Ising-like objective function has been used by J. Hopfield (1985) and others for finding the optimal tour in a traveling salesman problem using a neural network. This function contains four terms: one which reflects the length of the tour and three more penalty terms which attempt to maintain a feasible solution. These terms are combined into a weighted sum using four coefficients determined by the user. The quality of the final solution is very sensitive to these weighting factors, and good values for them are difficult to find when even a moderate number of cities are considered. A novel objective function is developed here that requires one weighting factor the value of which is easily determined. The use of this function in combination with an algorithm combining characteristics of neural networks and simulated annealing allows good, valid solutions to be found. >
Involvement of long terminal repeat U3 sequences overlapping the transcription control region in human immunodeficiency virus type 1 mRNA 3' end formation.

Abstract In retroviral proviruses, the poly(A) site is present in both long terminal repeats (LTRs) but used only in the 3' position. One mechanism to account for this selective poly(A) site usage is that LTR U3 sequences, transcribed only from the 3' poly(A) site, are required in the RNA for efficient processing. To test this possibility, mutations were made in the human immunodeficiency virus type 1 (HIV-1) U3 region and the mutated LTRs were inserted into simple and complex transcription units. HIV-1 poly(A) site usage was then quantitated by S1 nuclease analysis following transfection of each construct into human 293 cells. The results showed that U3 sequences confined to the transcription control region were required for efficient usage of the HIV-1 poly(A) site, even when it was placed 1.5 kb from the promoter. Although the roles of U3 in processing and transcription activation were separable, optimal 3' end formation was partly dependent on HIV-1 enhancer and SP1 binding site sequences.
Twenty-year follow-up of the Hancock modified orifice porcine aortic valve.

Abstract Background . The entire experience with the Hancock modified orifice porcine bioprosthetic aortic valve from 1976 to 1996 at the Brigham and Women's Hospital has been reviewed. Eight hundred forty-three patients received this valve with a total follow-up of 61,114 months, and a mean follow-up of approximately 72.5 months. There were 490 men and 353 women, and the predominate lesion was aortic stenosis (636 of 843); 365 (43%) patients required a concomitant coronary artery bypass graft operation. Methods . Patients were followed prospectively in the Brigham Cardiac Valve Data Registry, and the data were analyzed by the SAS statistical package, using actuarial survival curves and incidence per patient-year of morbidity and mortality. Results . The overall operative mortality was 45 of 843 (5.3%) with 23 of 478 (4.8%) for isolated aortic valve replacement and 22 of 365 (6.0%) for aortic valve plus coronary artery bypass graft operation. The major morbidity of this valve was structural valve dysfunction, which was significantly related to the age of the patient in whom the valve was placed. Actuarial probability of freedom from structural valve degeneration at 5, 10, and 15 years overall was 99% ± 1%, 79% ± 3% and 57% ± 4%, at 15 years, respectively. In patients younger than 50 years, freedom from structural valve dysfunction was 16% ± 8%, whereas in the age group older than 70 years it was 87% ± 5% ( p = 0.0005). Thromboembolism at 10 and 15 years was 81% ± 3% overall, 84% ± 2% in patients in normal sinus rhythm, and 57% ± 13% in patients with chronic atrial fibrillation. Conclusions . The Hancock modified orifice aortic valve, despite its more complicated fabrication, has been a reliable porcine bioprosthetic valve and can be used reliably in patients older than 70 years because of its low structural valve degeneration rate, and protection from stroke and anticoagulant hemorrhage in those patients in sinus rhythm.
When Problem Solving Prevents Organizational Learning

We propose that research on problem‐solving behavior can provide critical insight into mechanisms through which organizations resist learning and change. In this paper, we describe typical front‐line responses to obstacles that hinder workers’ effectiveness and argue that this pattern of behavior creates an important and overlooked barrier to organizational change. Past research on quality improvement and problem solving has found that the type of approach used affects the results of problem‐solving efforts but has not considered constraints that may limit the ability of front‐line workers to use preferred approaches. To investigate actual problem‐solving behavior of front‐line workers, we conducted 197 hours of observation of hospital nurses, whose jobs present many problem‐solving opportunities. We identify implicit heuristics that govern the problem‐solving behaviors of these front‐line workers, and suggest cognitive, social, and organizational factors that may reinforce these heuristics and thereby prevent organizational change and improvement.
Experimental validation of modular transformer converter based Convertible Static Transmission Controller for transmission grid management

For power flow control with specific attention to renewable energy resources based transmission in a meshed network, less complex coordinated control can be obtained with the proposed Convertible Static Transmission Controller (CSTC) concept which is connected across the substation power transformer and can be reconfigured to the required modes of operation. Convertible Static Transmission Controller (CSTC) is a versatile transmission controller which can perform several functions including power flow control for renewable resources transmission and transformer back-up for disaster management or life extension purposes. Different connecting configuration options (shunt-shunt, series-shunt, and series-series) can be obtained in the proposed transmission controller. In this paper, the control structure of CSTC in different modes of operation is presented, and dynamic performance of the CSTC based on the proposed control structures is further investigated in three different connecting configurations in PSCAD/EMTDC environment. Lab-scale experimental results are also presented to evaluate the performance of CSTC in three different modes of operation.
Venom-conducting teeth in a Triassic reptile

I REPORT here the discovery of highly distinctive reptilian teeth of early Late Triassic age from the Newark Supergroup of Virginia1, which are distinguished by the development of a deeply infolded median groove on both the labial and lingual surfaces of the blade-like crowns. On the basis of the close structural similarity to comparable features in the two living species of the lizard Heloderma and on the poison-fangs in extant venomous snakes2–5, it is suggested that these grooves functioned in venom conduction. This would represent the earliest instance of the use of oral toxins among reptiles (comprising diapsids and turtles) recorded to date.
Probing single molecules in microcavities

We describe recent results of experiments probing single molecules in the surface of spherical microcavities. Effects of spatial photoselection have been recently observed through changes in the single-molecule fluorescence photon statistics. In addition to being a sensitive probe of the highly interesting boundary region between classical and quantum mechanics, cavity-modified spontaneous emission and the possibility of single-molecule stimulated emission hold exciting promise as a means of exceeding sensitivity limitations such as photobleaching and absorption saturation in single molecule fluorescence detection. Ongoing efforts such as fluorescence imaging of single molecules on the surface of microspheres and attempts to observe single- molecule stimulated emission will also be described.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
DNA-binding and dimerization domains of adenosine 3',5'-cyclic monophosphate-responsive protein CREB reside in the carboxyl-terminal 66 amino acids

The expression of genes in response to cAMP is mediated by one or more trans-activator proteins, CREBs, that bind to cAMP-responsive enhancers (CREs) of the general motif 5'-TGACGTCA-3'. The carboxyl-terminal amino acid sequences of two isoforms of CREB, CREB-327 and CREB-341, deduced from the cDNAs consist of a positively charged (basic) region adjacent to a leucine zipper motif. Three peptides corresponding to the hypothetical DNA-binding and dimerization domains of CREB-327 were synthesized. A peptide that includes both the basic and leucine zipper domains binds to the CRE specifically. Moreover, this peptide readily forms CRE-binding heterodimers with full-length CREB both synthesized by in vitro cell-free translation and isolated from PC-12 cells, but did not heterodimerize with in vitro translated jun or fos. Two other peptides, either partially or totally lacking the basic region, but containing the intact leucine zipper domain, readily form dimers but do not bind to the CRE. We conclude that the carboxy-terminal basic and leucine zipper regions are necessary and sufficient for specific binding of CREB to the CRE as a homodimer. The leucine zipper domain is responsible for the dimerization, and the basic region confers binding specificity for the CRE. Heterodimerization of CREB-327 does not form heterodimers with jun or fos.
Management of lower extremity wounds in patients with peripheral arterial disease: a stratified conservative approach

Background Traditional wound care algorithms include aggressive detection of peripheral arterial disease (PAD) and treatment with revascularization for all patients with PAD and lower extremity wounds. Not every patient with PAD and a wound meets Transatlantic Inter-Society Consensus (TASCII) criteria for critical limb ischemia. We hypothesize that a conservative approach to selected patients with PAD and lower extremity wounds may be safe, provide acceptable limb salvage, and that failure of this approach does not translate into increased limb loss. Methods Veterans referred with PAD and nonhealing ulcers/wounds were prospectively enrolled into our Prevention of Amputation Care Team program. Patients were stratified according to management strategies which included revascularization, primary amputation, palliative limb care, and aggressive local care without revascularization (conservative group). Patients were assigned to conservative management group on the basis of transcutaneous oxygen measurement (TcpO2) and ankle–brachial index (ABI). Healing rates, need for “late” revascularization, major amputation rates, and survival of this conservative group were analyzed in terms of ABI and ankle pressures. Results Between January 2006 and March 2009, a total of 190 lower extremity wounds in 178 patients with PAD were analyzed. Forty-nine patients with 52 wounds (27.9%) were deemed candidates for conservative treatment. During mean follow-up of 14.5 months, complete wound healing was documented in 33 patients (35 wounds: 67%). Mean time to complete wound healing was 4.5 months. Predictors of healing included mean ABI (0.62 vs. 0.42 [ p 70 mm Hg ( p = 0.025). Sixteen patients (17 wounds: 33%) were not healed at the time of analysis. Of these, three patients (four wounds: 8%) showed active healing and 13 (13 wounds: 25%) failed conservative management. Nine patients (9 wounds: 17%) underwent late revascularization. There was one case of amputation (2%) and six cases of mortalities (12.2%). There was no increase in the rates of limb loss and mortality in patients who failed conservative management and underwent “late” revascularization. Conclusions Conservative management of lower extremity nonhealing wounds in selected patients with PAD is successful in over two-thirds of the patients. The failure of conservative management does not increase mortality or amputation rates. When the TcPO2 is >30 mm Hg, the ABI and the TASC II definition of critical limb ischemia predict wound healing and should be key factors in considering conservative therapy.
The amniotic sheet: a truly benign condition?

Objective Amniotic sheets are the result of uterine synechiae that have been encompassed by the expanding chorion and amnion. Radiologically they are seen as ‘shelves’ in the amniotic cavity. The benign nature of such amniotic sheets has been documented in many case series in the literature. The objective of this study was to determine the characteristics (if any) of amniotic sheets that predict fetal outcome. Methods Between January 2001 and December 2002, detailed scans were performed in 30 476 singleton pregnancies at 18–32 weeks' gestation. Of these, 44 cases of amniotic sheets were detected. The characteristics studied were site of amniotic sheet and whether the amniotic sheet was complete (i.e. no free edge seen on ultrasound) or incomplete (i.e. presence of free edge seen on ultrasound). The primary fetal outcome studied was stillbirth. Results The incidence of amniotic sheets was 0.14%. Two were complete and 42 were incomplete. Of the 38 cases with known outcomes there were two intrauterine deaths. There was no association between fetal outcome and the uterine location of the amniotic sheet (i.e. upper two-thirds vs. lower third, P = 0.5). There was, however, an association between the completeness of the amniotic sheets and intrauterine death (P = 0.002). Both instances of intrauterine death occurred in the two cases with complete amniotic sheets. Postmortem examination suggested that cord accidents were the cause of intrauterine death in both cases. Conclusions This study supports the view that incomplete amniotic sheets are benign. It also suggests for the first time that complete amniotic sheets may be associated with intrauterine death. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
A Generalization of Bieberbach's Theorem.

In 1912 Bieberbach proved that every compact flat Riemannian manifold M is finitely covered by a flat torus. More precisely, M has the form (F\G)/H where G is a group of translations of Euclidean space, F c G is a discrete subgroup, and H is a finite group of isometries of the space of right cosets F\G. For a proof see e.g. Wolf [18]. The condition that M has a flat Riemannian metric can be separated into two conditions. First, M has an affine structure a distinguished covering by coordinate charts, whose coordinate changes are affine. Second, M has a Riemannian metric whose coefficients in the affine charts are constants. In this paper we relax the second condition. A polynomial Riemannian metric on the affine manifold M is a Riemannian metric whose local expression in affine coordinates has the form ~gi~(x)dxidx ~ where the gij are polynomial functions on Euclidean space E. By letting the gij be rational functions on E, we arrive at the more general notion of a rational Riemannian metric. (It is not assumed that these expressions define Riemannian metrics on all of E.) The object of this paper is to determine which affine manifolds have polynomial Riemannian metrics and to give examples of affine manifold having rational Riemannian metrics.
Examination of the effects of increasing Gs protein on β2-adrenergic receptor, Gs, and adenylyl cyclase interactions

We have examined the effect of increased Gs protein levels on the abilities of three different β2-agonists to induce GTP shifts and stimulate adenylyl cyclase response in an effort to investigate the kinetic association between the β2-adrenergic receptor Gs and adenylyl cyclase. Agonist competition binding analysis and adenylyl cyclase concentration-response assays revealed that increases in Gs protein resulted in proportional increases in the areas of the GTP shift and adenylyl cyclase activity. Changes in the magnitude of the GTP shift were evaluated with a novel and straightforward approach for analyzing the GTP shift data that allowed us to determine the proportion of high agonist affinity binding receptor population and the apparent dissociation constant between the agonist bound receptor and Gs, regardless of the Gs protein level or the type of β2-agonist. Using this method, we concluded that increased Gs results in the accumulation of the receptor population displaying high affinity towards agonist (HRGs) by increasing the number of receptor-Gs complexes (to a receptor:Gs protein ratio of about 0.7 at maximal Gs expression) without affecting the affinity between hormone bound receptor and Gs. Using the Gs protein levels determined with our novel analysis, we ran simulations using the theoretical shuttle model equation that relates the EC50 to available Gs. Fitting the simulations to experimental data required a receptor to catalytic unit ratio of 0.45 and revealed at least two distinct stages for β2-agonist-stimulated adenylyl cyclase activity, namely, the activation of Gs by the β2-adrenergic receptor (a step whose rate is dependent on the type of agonist used to stimulate activity), and the activation of adenylyl cyclase by active Gs (a step whose rate is independent of the type of agonist).
Dopamine autoreceptor stimulation increases protein carboxyl methylation in striatal slices.

: We have investigated the possibility that protein carboxyl methylation is involved in coupling dopamine autoreceptor stimulation to intracellular events such as inhibition of dopamine synthesis or release. The dopamine agonists apomorphine and TL-99 were found to stimulate methyl ester formation in striatal slices preloaded with [3H]methionine. The stimulatory effects of apomorphine were dose-dependent, were not due to changes in [3H]methionine uptake or S-[3H]-adenosyl-methionine formation, and were blocked by the stereospecific dopamine antagonist (+)-butaclamol. Stimulation of methyl ester formation by dopamine agonists is readily observed only when slices are prepared from rats pretreated with reserpine to deplete endogenous brain catecholamines. This suggests that in slices prepared from normal rats endogenous dopamine (DA) released during slice preparation and incubation masks the effects produced by exogenously administered dopamine agonists on protein carboxyl methylase (PCM) activity. Additional experiments suggested that the effects of apomorphine were mediated via an interaction with DA autoreceptors rather than with postsynaptic DA receptors. Destruction of monoamine neurons and their associated autoreceptors by injecting 6-hydroxydopamine into the area of the medial forebrain bundle abolished the stimulatory effects of apomorphine on methyl ester formation in striatal slices. Furthermore the putative selective DA autoreceptor agonist EMD 23 448 was also found to stimulate methyl ester formation in striatal slices. These findings, discussed in terms of calcium-dependent functions, support the hypothesis that PCM may be a key component in the biochemical transduction of DA autoreceptor stimulation.
Leptospirosis in Swine Caused by Leptospira Pomona

Reports from various parts of the world indicate that swine are important hosts for Leptospira pomona.1'10 Evidence of infection by this organism has also been demonstrated in other species, including cattle and man.8-10 It has been established that pigs may serve as reservoir hosts for the disease in man;2 furthermore, there is reason to believe tihat an interchange of infection occurs between swine and cattle.10-11 The disease produced in pigs by Lept. pomona has not. yet been fully defined, nor has its significance been appraised. The following investigations were initiated to consider certain aspects of the problem of leptospirosis in swine that seemed to be of importance: (a) a determination of the incidence of Lept. pomona in the swine population, (b) the characterization under controlled experimental conditions of Lept. pomona infection in swine, (c) the possibility that nfected pigs might be a reservoir of infection for cattle.
The relationship of early-onset regular smoking to alcohol use, depression, illicit drug use, and other risky behaviors during early adolescence: Results from the youth supplement to the Third National Health and Nutrition Examination Survey

Abstract Purpose: Recently we found that the early onset of regular tobacco use is as predictive of lifetime drug use and depressive disorders as it is of alcohol use disorders [Alcohol.: Clin. Exp. Res. 23 (1999) 513.]. This finding, which paralleled findings regarding early onset of alcohol use [J. Subst. Abuse 10 (1998) 59.], suggested that early regular use of any drug might simply be an indicator of risk for a constellation of problem behaviors. The purpose of the present study is to test this hypothesis as well as to study the strength and patterns of associations among these problem behaviors already present among youth. The results will permit description of more precise profiles to identify groups of children at risk. Methods: Using data for respondents aged 12–16 from the Third National Health and Nutrition Examination Survey (NHANES III), descriptive statistics were calculated and logistic regression models were estimated. Results: Descriptive analyses indicated that in comparison with those who never smoked, or who simply experimented, early-onset regular smokers, both those who began at age 13 or younger and those who did so between 14 and 16, were those most likely to use alcohol and other drugs as well as have school problems and early sexual experiences culminating in pregnancy. Multivariate logistic regression analyses were conducted to assess the associations among these high-risk behaviors. Implications: These results support the hypothesis that early onset of smoking is but an indicator of a syndrome of problem behaviors already in place during childhood. They also suggest that the significance of an age onset variable may differ depending on the age of the sample used. As follow-up data are collected, we expect to learn much about the natural course of the distinct risk groups identified in the analyses by studying longitudinally this nationally representative group of early adolescents.
Incidence of Parthenogenesis in Eggs of Various Strains and Varieties of Domestic Turkeys, Meleagris Gallopavo

Abstract Since 1953 considerable work at this Station has been devoted to the study of parthenogenetic development in Beltsville Small White (BSW) turkey eggs. Most of the work dealt with the incidence of parthenogenesis as influenced by selection and by environmental factors. It also was of interest to determine how widespread this form of development was, and to what extent it occurred, in eggs of other varieties and strains of domestic turkeys. These tests involved a total of 3,048 unfertilized eggs from 116 young turkeys representing 9 different varieties, strains, and variety crosses. Three of the groups were secured from commercial sources, the remainder were from State experiment stations. None of the hens involved had been selected for a high incidence of parthenogenetic development. In conducting the parthenogenetic tests, the same general procedures were followed as those outlined by Olsen and Marsden (1953), i.e., eggs from virgin hens were incubated at . . .
Measurement of lesions by endoscopy : an overview

Background and Study Aims : Endoscopic measurement of lesion size is important in the design and conduct of clinical trials, in determining prognosis and choosing forms of therapy. Endoscopes are constructed with wide-angle lenses that distort the image significantly by creating a relative compression of points in the periphery of the image. Methods : Published studies on endoscopic lesion measurement were identified using a computerized search of electronic databases (MedLine). Results and Conclusions : Currently used clinical methods of estimating lesion size (visual estimation or comparison to a target of known size, e.g., open biopsy forceps) are flawed and inaccurate. Results from studies using image processing or the stereoendoscope are particularly promising for the future.
Parameter estimation and sensitivity analysis in an agent-based model of Leishmania major infection

Computer models of disease take a systems biology approach toward understanding host-pathogen interactions. In particular, data driven computer model calibration is the basis for inference of immunological and pathogen parameters, assessment of model validity, and comparison between alternative models of immune or pathogen behavior. In this paper we describe the calibration and analysis of an agent-based model of Leishmania major infection. A model of macrophage loss following uptake of necrotic tissue is proposed to explain macrophage depletion following peak infection. Using Gaussian processes to approximate the computer code, we perform a sensitivity analysis to identify important parameters and to characterize their influence on the simulated infection. The analysis indicates that increasing growth rate can favor or suppress pathogen loads, depending on the infection stage and the pathogen's ability to avoid detection. Subsequent calibration of the model against previously published biological observations suggests that L. major has a relatively slow growth rate and can replicate for an extended period of time before damaging the host cell.
The Past 25 Years of Surgery

The past 25 years have seen an explosion in interest and progress in the diagnosis and treatment of vitreoretinal diseases, especially retinal detachments. This progress has paid high dividends in the prevention of blindness and the clinical care of patients. The major advances during this period are the development of a binocular stereoscopic indirect ophthalmoscope combined with scleral depression, the introduction of a scleral buckling procedure to close retinal breaks, the development of instruments capable of producing controlled focal irritation in the ocular fundus, and the advent of direct surgical removal of the vitreous.
Large strain deformation of polycrystalline metals at low homologous temperatures

Abstract Large strain compression data (true strains to about −3.0) are presented for polycrystalline α U and α Fe at room temperature. The results, together with other published data at low homologous temperatures (≈0.2 Tm), where Tm is the absolute melting temperature, suggest that a steady-state flow stress σs is approached after extensive strain-hardening, α U exhibits a very high strain-hardening rate, with σs ≈ 2900 MPa (420 ksi) indicating that cold-working is a very potent method of strengthening this metal. All the data evaluated can be fit by the stress-strain relation σ = σs− exp (−(Ne)p)(σs− σy), where σy is the yield stess, p is a constant equal to a for the metals analyzed, N is a constant associated with the strain-hardening characteristics of a material, σ is true stress, and e is true strain.
Interleukin-1 in human ovarian cells and in peripheral blood monocytes increases during the luteal phase: Evidence for a midcycle surge in the human

Abstract OBJECTIVE : Resident ovarian macrophages are thought to be critically involved in cyclic ovarian events. A prominent macrophage product, interleukin-1, has been shown to affect ovarian cell function. In this report we present evidence for an intrafollicular periovulatory interleukin-1 surge. Additionally, we demonstrate that interleukin-1β messenger ribonucleic acid in peripheral blood monocytes increases threefold during the luteal phase of the menstrual cycle over that found in the follicular phase. STUDY DESIGN : Follicular fluid cells isolated as a byproduct of transvaginal oocyte retrievals in gonadotropin-stimulated in vitro fertilization cycles were immunoprobed for the presence of interleukin-1 protein. Late follicular phase cumulus and granulosa cells obtained from an aspirated preovulatory follicle were likewise probed. RESULTS : Although the in vitro fertilization – retrieved cells stained positive for interleukin-1 protein, the late follicular phase cells were devoid of the protein. Granulosa cells from in vitro fertilization cycles were examined for interleukin-1 protein binding sites with iodinated interleukin-1α protein. These cells were found to have approximately 2000 binding sites per cell. Poly A + messenger ribonucleic acid isolated from peripheral blood monocyte samples from women during the follicular and luteal phases and from male controls were probed for interleukin-1 ribonucleic acid content by means of Northern analysis. The luteal samples contained a threefold higher interleukin-1 messenger ribonucleic acid content than did the follicular phase samples or the controls. CONCLUSION: The ovarian interleukin-1 protein increase taken together with increased peripheral blood monocyte interleukin-1 messenger ribonucleic acid suggests that interleukin-1 production increases at midcycle. (AM J OBSTET GYNECOL 1994; 170:1000-7.)
Saddam's failed counterstrike: Terrorism and the Gulf War

As the 1990–1991 Gulf crisis unfolded, leaders of the UN coalition against Iraq became increasingly concerned about the possibility of terrorism accompanying the initiation of hostilities with Bagh...
Use of gracilis muscle as a “walking” flap for repair of a rectovaginal fistula

Summary Rectovaginal fistula is a rare but debilitating complication of a variety of pelvic operations. Management remains challenging with high incidence of failure. The majority of patients eventually require surgical intervention. Several surgical procedures have been described including local repair, muscle transposition, or laparotomy. Among the muscles used for rectovaginal fistula repair, the gracilis muscle interposition flap is an excellent option. However, in a small percentage of cases it fails, and alternative techniques should be entertained. We describe the case of a 50-year-old female who underwent stapled hemorrhoidopexy that was complicated by a 30 mm rectovaginal fistula, and required fecal diversion. Four months later, gracilis muscle interposition flap was performed but failed. The right gracilis flap was then re-used successfully as a "walking" flap. At three months the patient underwent closure of the temporary loop ileostomy, and continues to do well with no evidence of rectovaginal fistula recurrence one year later. To our knowledge, this is the first report of the use of a gracilis muscle as a "walking" flap for repair of a rectovaginal fistula, and should be considered as an alternative appropriate treatment for persistent rectovaginal fistulas after failure of initial gracilis muscle interposition flap.