cssi/SciSciGPT-SciSciNet huggingface dataset:
Incidence rates and risks of diethylstilbestrol-related clear-cell adenocarcinoma of the vagina and cervix: Update after 40-year follow-up.

Abstract Objective Women exposed to diethylstilbestrol (DES) in utero are at increased risk for the development of vaginal and cervical clear cell adenocarcinoma (CCA) at younger age. It is unknown if a second peak will occur in later life, the ages when CCA developed spontaneously in the pre-DES era. The complete epidemiologic curve of CCA has not been reported, yet. Methods We reviewed 720 cases of CCA from the CCA registry at the University of Chicago through 2014. Incidence rates and cumulative risks for CCA were calculated based on white women born in the U.S. from 1948 through 1971. Results In 420 CCA cases there was documented evidence of prenatal DES exposure. 80% were among those between ages 15 and 31 but some occurred as late as age 55. A small second peak occurred around age 42. The risk of DES-related CCA was highest in the 1951–1956 birth cohort and this birth cohort effect closely correlated with DES prescriptions over time in the U.S. (r=0.98, P =0.005). By age 50, the cumulative risk of CCA was 1 per 750 exposed women. CCA cases without evidence of DES exposure had similar ages, year of diagnosis, and birth cohort patterns as the documented DES-exposed cases, suggesting that some negative cases were exposed. Their inclusion raises the cumulative risk of CCA to 1 per 520. Conclusion With the largest data available, our results confirmed the association between prenatal DES exposure and clear cell adenocarcinoma. The study also refines the risks of DES-related CCA.
Quasistatic Error Modeling and Model Testing for a 5-Axis Machine

Abstract This paper presents an approach to modeling the quasistatic errors of a 5-axis machine tool with one redundant axis. By introducing errors to the ideal joints and shape transforms of the kinematics of the machine, an error model is obtained. First order error characteristics are used to parameterize the introduced errors. It is found that of the 52 introduced error parameters, only 32 have a linearly independent effect on the volumetric errors observed in the machine's workspace. To identify these error parameters, the volumetric error components at 290 randomly chosen points are measured with a laser tracker. The unknown parameters are obtained by least-squares estimation, and the resulting model able to reduce average magnitude of the volumetric error vectors at these points by an average of 90% of their original values. Further, the identified model was used to predict the errors observed in two independent test point sets (each set consisting of 48 points). A 75% reduction in the average magnitude of the error vectors was observed. A large fraction of the residual errors was found to be attributable to the thermal drift of the machine during the experiments where were not conducted in a thermally controlled environment and the positioning repeatability of the machine.
Coded caching for combination networks with cache-aided relays

We study a two-hop cache-aided network, where a layer of relay nodes connects a server and a set of end users, i.e., a combination network. We consider the case where both the relay nodes and the end users have caching capabilities. We provide upper and lower bounds which are applicable to any combination network, noting that previous work had focused on models where the relays do not have caches as well as schemes that were suitable for a special class of combination networks. Utilizing maximum distance separable (MDS) codes, we jointly optimize the placement and the delivery phases, demonstrating the impact of cache memories in alleviating the delivery load over the two hop communications. Moreover, we show how cooperation between the relay nodes and the end users can effectively replace the server during the delivery phase whenever the total memory at each end user and its connected relay nodes is sufficient to store the database.
Sphincterotomy and Stents in Benign and Malignant Disorders and Biliary ERCP

Advances in cross-sectional imaging, including magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS), have rendered endoscopic retrograde cholangiopancreatography (ERCP) a primarily therapeutic modality. Biliary sphincterotomy and stent placement are frequently part of the management of large bile duct stones, the relief of obstructive jaundice associated with benign and malignant strictures, the treatment of iatrogenic biliary leaks, etc. An individual’s training largely dictates their ERCP technique.
Iatrogenic Infertility After Curative Stem Cell Transplantation in Patients With Sickle Cell Disease

Allogeneic hematopoietic stem cell transplantation (HSCT), the only known cure for sickle cell disease, involves pretransplantation regimens (alkylating agents and radiation) that may cause sterili...
An Investigation of the Effects of Crack Front Curvature on the Crack-Tip Opening Displacement of A707 Steel

This paper examines the effects of crack front curvature on the fracture toughness (crack-tip opening displacement) of A707 steel. Fracture mechanics specimens, in which the radii of curvature of the crack fronts are controlled in an effort to simulate potential variations in crack front profiles in fracture experiments, were produced by machining and fatigue pre-cracking. Three-point bend crack-tip opening displacements (CTODc) were measured in accordance with the ASTM E-1290 code. The results show that the critical CTODc increases with increasing crack front curvatures between 0.05 and 0.17 mm−1. In all cases, stable crack growth and final catastrophic failure of the specimens are found to occur by transgranular ductile dimpled fracture, in which the ductile dimples are nucleated around MnS or Al2(Mg)O3 inclusions. The implications of the results are discussed for the measurement of critical CTODc in specimens with varying levels of crack front curvature.
Network: Theorizing Knowledge Work in Telecommunications

How does a telecommunications company function when its right hand often doesn't know what its left hand is doing? How do rapidly expanding, interdisciplinary organizations hold together and perform their knowledge work? In this book, Clay Spinuzzi draws on two warring theories of work activity - activity theory and actor-network theory - to examine the networks of activity that make a telecommunications company work and thrive. In doing so, Spinuzzi calls a truce between the two theories, bringing them to the negotiating table to parley about work. Specifically, about net work: the coordinative work that connects, coordinates, and stabilizes polycontextual work activities. To develop this uneasy dialogue, Spinuzzi examines the texts, trades, and technologies at play at Telecorp, both historically and empirically. Drawing on both theories, Spinuzzi provides new insights into how net work actually works and how our theories and research methods can be extended to better understand it.
Equal Access to Information? Evaluating the Accessibility of Public Library Web Sites in the State of Maryland

Public libraries in the United States have a long and proud tradition of providing access to information for all residents. Public libraries have been the equaliser - providing access to books, and both printed and electronic information, regardless of race, gender, religion, economic status, or disability. Since the mid-1990s, public libraries have also been providing direct access to the Internet for patrons who come to visit. And since that first burst of access to the Internet within public library buildings, libraries have been pushing to provide access to their resources through the Internet, so that patrons can search library catalogues, reserve resources and renew materials, and even access digital libraries of documents, all wherever the patrons happen to have Internet access - at home, work, or using mobile phones (Jaeger et al., 2011)
Analysis of Blind Source Separation Techniques for Eye Artifact Removal

Evaluation of several different eye artifact removal techniques for electroencephalographic data is presented in this paper. Data is taken from an emotion recognition experiment, in which subjects undergo five different emotions (joy, sadness, disgust, fear, and neutral). Preprocessing for the EEG Data includes filtering with a Butterworth band-pass filter and a 60Hz notch filter. Three different types of eye artifact removal techniques are explored using the preprocessed data: EOG based linear regression, Principal Component Analysis, and Independent Component Analysis. All techniques used electrooculographic (EOG) data to determine the criteria for feature extraction and removal. Evaluations from our experiments show that all techniques significantly reduce the effects of eye blinks and eye movements in the EEG. The developed metric used in experimentation shows that Independent Component Analysis reduced eye artifacts the best while keeping EEG portions unchanged (Average SSE of 0.1126 for clean EEG portions).
R. A. Fisher on the Design of Experiments and Statistical Estimation

On this occasion of the centenary year of Fisher’s birth, my purpose in this talk is to consider the relation between two of Fisher’s major contributions: his theory of experimental design and his theory of statistical estimation.
What tangled webs we weave.

Knots have been rigorously studied since the 1860s, but only in the past 30 years have they been made in the laboratory in molecular form. Now, the most complex small-molecule examples so far — a composite knot and an isomeric link, each with nine crossings — have been prepared.
Pre-therapy neutrophil-to-lymphocyte ratio and lymphocyte-to-monocyte ratio do not predict survival in patients treated with immune checkpoint inhibitors.

e15092Background: Inflammatory and immune responses in the tumor microenvironment play a critical role in tumor progression and host immune response. Neutrophil-to-lymphocyte ratio (NLR) and lympho...
Stability and Change: Policy Evolution on the Supreme Court of Canada, 1945–2005

Studies of the Supreme Court of Canada (SCC) focus largely on its policy-making role and its interpretation of the Charter of Rights. However, less studied are the Court's decisions in earlier periods, especially in comparison to the Charter years and in cases beyond civil rights and liberties. This study fills a gap in the scholarship by analyzing the universe of decisions from 1945 to 2005 in criminal, tax and tort cases. Utilizing Baum's (1988, 1989) method to examine policy change, I explore policy trends on the Supreme Court. The findings suggest that, for the most part, the SCC has remained a stable, consistent body over the course of its modern history. It appears that most of the variation in judicial output across time is due to issue change with some shifts due to personnel and membership change.
Estimating gluon saturation in dijet photoproduction in UPC

We study dijet production in the ultra-peripheral heavy ion collisions (UPC) at LHC within the saturation formalism. More precisely, we use an approach which is the large-$p_T$ approximation to the Color Glass Condensate on one hand, and the small-$x$ limit of the transverse momentum dependent (TMD) factorization on the other. The direct component of the dijet production in UPC at small $x$ probes the so-called Weizsacker-Williams (WW) TMD gluon distribution, which is not accessible in more inclusive processes, where rather the dipole TMD gluon distribution is probed. Although the WW TMD gluon distribution is not known from data, it can be calculated from the data-restricted dipole TMD gluon distribution using the mean field approximation. Using such approximated WW distribution we calculate various dijet observables in UPC and estimate the saturation effects.
Blaming the Victim of Acquaintance Rape: Individual, Situational, and Sociocultural Factors

Victims of rape are uniquely vulnerable for being blamed for their assault relative to victims of other interpersonal crimes and thus much research has been conducted to understand why this is the case. But the study of victim blaming in acquaintance rape cases is hindered by contradictory empirical results. Early investigations in victim blaming often treated acquaintance rapes and stranger rapes as synonymous and thus much of these data are suspect for drawing conclusions particular to acquaintance rape. This paper provides a comprehensive review of the research literature on victim blame in acquaintance rape cases, highlighting inconsistencies and drawing particular attention to areas of research in need of further exploration. Specifically, we review the commonly studied individual (perceiver) factors that influence victim blaming, as well as common situational (target) factors included or manipulated within sexual assault scenarios. Our review reveals many inconsistent findings and interactions between perceiver and scenario factors. In an effort to make sense of these complex interactions and inconsistent findings, we suggest a need for more transparency in describing the scenarios used in research on victim blaming in sexual assault cases and greater empirical attention to sociocultural factors that may influence blaming tendencies.
Real-time sediment plume modeling in the Southern California bight

With advances in engineering and technology, mining the deep sea for untapped rare metal resources from the bottom of the ocean has recently become economically viable. However, extracting these metal ores from the seabed creates plumes of fine particles that are deposited at various depths within the ocean, and these may be extremely harmful to the marine ecosystems and its components. Thus, for sustainable management, it is of utmost importance to carefully monitor and predict the impact of such harmful activities including plume dispersion on the marine environment. To forecast the plume dispersion in real-time, data-driven ocean modeling has to be coupled with accurate, efficient, and rigorous sediment plume transport computations. The goal of the present paper is to demonstrate the real-time applications of our coupled 3D-and time data-driven ocean modeling and plume transport forecasting system. Here, the region of focus is the southern California bight, where the PLUMEX 2018 deep sea mining real-time sea experiment was recently conducted (23 Feb - 5 Mar, 2018). Specifically, we demonstrate the improved capabilities of the multiscale MSEAS primitive equation ocean modeling system to capture the complex oceanic phenomenon in the region of interest, the application of the novel method of composition to efficiently and accurately compute the transport of sediment plumes in 3D+1 domains, and the portability of our software and prediction system to different operational regions and its potential in estimating the environmental impacts of deep sea mining activities, ultimately aiding sustainable management and science-based regulations.
Au2+ cannot catalyze conversion of methane to ethene at low temperature

The previously reported conversion of methane to ethene catalyzed by Au2+ at thermal energies, at odds with established thermodynamics, is investigated through a combination of experiments under both single-collision conditions using a guided ion beam tandem mass spectrometer (GIBMS) apparatus and at higher pressures using a selected-ion flow tube (SIFT) apparatus, as well as through density functional calculations. Production of Au2(C2H4)+ (or m/z 422) or Au2(C2D4)+ (or m/z 426) is significantly lower in the higher pressure SIFT experiments relative to previously reported results. The amount observed is consistent with a pathway initiating from a small fraction of a reactive species, potentially electronically excited Au2+* or Au2O+, isobaric with Au2(CH4)+. Extensive theoretical exploration of the potential energy surface for Au2(CH4)+ + CH4 shows no low-energy pathway that is consistent with ethene formation, with prohibitive barriers of 1–2 eV calculated along all identified reaction coordinates, consistent with previous calculations. GIBMS data do show the production of m/z 422 in the reaction of Au2(CH4)+ + CH4, consistent with the proposed key intermediate, but also provide evidence that this observed species is Au2(CO)+ arising from Au2O+, not Au2(C2H4)+ arising from Au2(CH4)+. The present results are consistent with the established thermochemistry for methane-to-ethene conversion, which unambiguously demonstrates that such conversion cannot proceed at thermal energies regardless of the presence of Au2+.
Elevated Neuroglobin Lessens Neuroinflammation and Alleviates Neurobehavioral Deficits Induced by Acute Inhalation of Combustion Smoke in the Mouse

Acute inhalation of combustion smoke produces long-term neurologic deficits in survivors. To study the mechanisms that contribute to the development of neurologic deficits and identify targets for prevention, we developed a mouse model of acute inhalation of combustion smoke, which supports longitudinal investigation of mechanisms that underlie the smoke induced inimical sequelae in the brain. Using a transgenic mouse engineered to overexpress neuroglobin, a neuroprotective oxygen-binding globin protein, we previously demonstrated that elevated neuroglobin preserves mitochondrial respiration and attenuates formation of oxidative DNA damage in the mouse brain after smoke exposure. In the current study, we show that elevated neuronal neuroglobin attenuates the persistent inflammatory changes induced by smoke exposure in the mouse brain and mitigates concordant smoke-induced long-term neurobehavioral deficits. Specifically, we found that increases in hippocampal density of GFAP and Iba-1 positive cells that are detected post-smoke in wild-type mice are absent in the neuroglobin overexpressing transgenic (Ngb-tg) mice. Similarly, the smoke induced hippocampal myelin depletion is not observed in the Ngb-tg mice. Importantly, elevated neuroglobin alleviates behavioral and memory deficits that develop after acute smoke inhalation in the wild-type mice. Taken together, our findings suggest that the protective effects exerted by neuroglobin in the brains of smoke exposed mice afford protection from long-term neurologic sequelae of acute inhalation of combustion smoke. Our transgenic mouse provides a tool for assessing the potential of elevated neuroglobin as possible strategy for management of smoke inhalation injury.
Chemical Flexibility of Mg in Pnictide Materials: Structure and Properties Diversity

Magnesium, element no. 12 on the periodic table, is the second member of the alkaline-earth metal family. Often, Mg is considered as an electropositive metal like its heavier congeners, Ca, Sr, and...
Context Matters: Using Art-Based Science Experiences to Broaden Participation beyond the Choir.

Dedicated science learning spaces such as science museums, science cafes, or science media attract mostly those who seek out science learning experiences. This self-selection represents a major cha...
Pseudomonas Can Survive Tailocin Killing via Persistence-Like and Heterogenous Resistance Mechanisms

Phage tail-like bacteriocins (tailocins) are bacterially produced protein toxins that mediate competitive interactions between cocolonizing bacteria. Both theoretical and experimental research has shown there are intransitive interactions between bacteriocin-producing, bacteriocin-sensitive, and bacteriocin-resistant populations, whereby producers outcompete sensitive cells, sensitive cells outcompete resistant cells, and resistant cells outcompete producers. These so-called rock-paper-scissors dynamics explain how all three populations occupy the same environment, without one driving the others extinct. Using Pseudomonas syringae as a model, we demonstrate that otherwise sensitive cells survive bacteriocin exposure through a physiological mechanism. This mechanism allows cells to survive bacteriocin killing without acquiring resistance. We show that a significant fraction of the target cells that survive a lethal dose of tailocin did not exhibit any detectable increase in survival during a subsequent exposure. Tailocin persister cells were more prevalent in stationary- rather than log-phase cultures. Of the fraction of cells that gained detectable resistance, there was a range from complete (insensitive) to incomplete (partially sensitive) resistance. By using genomic sequencing and genetic engineering, we showed that a mutation in a hypothetical gene containing 8 to 10 transmembrane domains causes tailocin high persistence and that genes of various glycosyltransferases cause incomplete and complete tailocin resistance. Importantly, of the several classes of mutations, only those causing complete tailocin resistance compromised host fitness. This result indicates that bacteria likely utilize persistence to survive bacteriocin-mediated killing without suffering the costs associated with resistance. This research provides important insight into how bacteria can escape the trap of fitness trade-offs associated with gaining de novo tailocin resistance.IMPORTANCE Bacteriocins are bacterially produced protein toxins that are proposed as antibiotic alternatives. However, a deeper understanding of the responses of target bacteria to bacteriocin exposure is lacking. Here, we show that target cells of Pseudomonas syringae survive lethal bacteriocin exposure through both physiological persistence and genetic resistance mechanisms. Cells that are not growing rapidly rely primarily on persistence, whereas those growing rapidly are more likely to survive via resistance. We identified various mutations in lipopolysaccharide biogenesis-related regions involved in tailocin persistence and resistance. By assessing host fitness of various classes of mutants, we showed that persistence and subtle resistance are mechanisms P. syringae uses to survive competition and preserve host fitness. These results have important implications for developing bacteriocins as alternative therapeutic agents.
Arthroscopic Management of Elbow Contractures

Elbow contracture is a common complication after an elbow injury and can limit the patient’s ability to perform essential daily activities. Historically elbow contracture release was performed through an open approach. Recently, with advances in elbow arthroscopy, there has been increased interest in performing contracture release through this minimally invasive approach. Arthroscopy offers several potential advantages including enhanced intra-articular visualization, decreased soft tissue trauma, less postoperative pain, and improved cosmesis. Despite these advantages, elbow arthroscopy has inherent risks due to the proximity of neurovascular structures to the portal sites. The risk for injury to these structures has been shown to be statistically higher in patients with an elbow contracture or patients undergoing capsular release.
Safety and Tolerability of Fluoroquinolones in Patients with Staphylococcal Periprosthetic Joint Infections.

BACKGROUND Fluoroquinolones (FQs) are known to be accompanied by significant risks. However, the incidence of adverse events (ADEs) resulting in unplanned drug discontinuation when used for periprosthetic joint infections (PJIs) is currently unknown. METHODS This study included 156 patients over the age of 18 treated for staphylococcal PJI with debridement, antibiotics, and implant retention between 1 January 2007 and 21 November 2019. Of the 156 patients, 64 had total hip arthroplasty (THA) and 92 had total knee arthroplasty (TKA) infections. The primary outcome was rate of unplanned drug discontinuation. Secondary outcomes included incidence of severe ADEs, unplanned rifamycin discontinuation, mean time to unplanned regimen discontinuation, and all-cause mortality. RESULTS Overall, unplanned drug discontinuation occurred in 35.6% of patients in the FQ group and 3% of patients in the non-FQ group. The rate of unplanned discontinuation of FQ regimens as compared with non-FQ regimens was 27.5% vs 4.2% (P = .021) in THA infections and 42% vs 2.4% (P < .001) in TKA infections. There was no significant difference in severe ADEs between FQ and non-FQ regimens in both THA and TKA infections. The overall rate of nonsevere ADEs in FQ compared with non-FQ regimens was 43.3% vs 6.1% (P < .001). FQs were associated with tendinopathy, myalgia, arthralgia, and nausea. CONCLUSIONS A significantly higher rate of unplanned drug discontinuation was associated with FQ as compared with non-FQ regimens. This provides a real-world view of the implications of FQ-related ADEs on unplanned discontinuation when used in prolonged durations for the management of staphylococcal PJIs.
Dumping, Antidumping Duties, and Price Undertakings: Policy Implications of Trade in Quality-Differentiated Products

This paper examines which types of firms, from a developed country (DC) or a less developed country (LDC), tend to practice dumping, using a two-market equilibrium analysis of trade in "like" products. Specifically, we present a vertical product differentiation model of duopolistic competition between a DC firm and an LDC firm under free trade to show that the DC firm sells a higher-quality product without dumping. In contrast, the LDC firm sells a lower-quality product and practices dumping in the DC market by charging a price lower than the product's price in its LDC market. As such, dumping is a signal of lower product quality. The imposition of an antidumping duty by the DC government increases domestic welfare. The LDC's social welfare may increase if its exporting firm accepts a price-undertaking rather than dumping. From the perspective of world welfare, defined by aggregating the welfare of the trading countries (DC and LDC), the trade damage measure of imposing antidumping fines on LDC dumping is Pareto-improving compared to free trade (under which dumping takes place) and price-undertakings.
Adult residual rectourethral fistula and diverticulum presenting decades after imperforate anus repair: a case report.

This report describes a rare surgical case of an intraabdominal mass in a middle-aged patient 40 years after imperforate anus repair. A 44-year-old Latino male with history of repaired anorectal malformation presented with recurrent urinary tract infections and rectal prolapse with bothersome bleeding and fecal incontinence. During his preoperative evaluation, he was initially diagnosed with a prostatic utricle cyst on the basis of magnetic resonance imaging findings, which demonstrated a cystic, thick-walled mass with low signal contents that extended inferiorly to insert into the distal prostatic urethra. However, at the time of surgical resection, the thick-walled structure contained an old, firm fecaloma. The final pathology report described findings consistent with colonic tissue, suggesting a retained remnant of the original fistula and diverticulum. Although rare, persistent rectourethral fistula tracts and rectal diverticula after imperforate anus repair can cause symptoms decades later, requiring surgical intervention. This is an important diagnostic consideration for any adult patient with history of imperforate anus.
Dug: A Semantic Search Engine Leveraging Peer-Reviewed Literature to Span Biomedical Data Repositories

Abstract Motivation As the number of public data resources continues to proliferate, identifying relevant datasets across heterogenous repositories is becoming critical to answering scientific questions. To help researchers navigate this data landscape, we developed Dug: a semantic search tool for biomedical datasets that utilizes evidence-based relationships from curated knowledge graphs to find relevant datasets and explain why those results are returned. Results Developed through the National Heart, Lung, and Blood Institute’s (NHLBI) BioData Catalyst ecosystem, Dug can index more than 15,911 study variables from public datasets in just over 39 minutes. On a manually curated search dataset, Dug’s mean recall (total relevant results/total results) of 0.79 outperformed default Elasticsearch’s mean recall of 0.76. When using synonyms or related concepts as search queries, Dug’s (0.28) far outperforms Elasticsearch (0.1) in terms of mean recall. Availability and Implementation Dug is freely available at https://github.com/helxplatform/dug. An example Dug deployment is also available for use at https://helx.renci.org/ui. Contact awaldrop@rti.org or scox@renci.org
Experimentally-Induced Alterations in the Kinetics of Erythrocyte Sickling

Erythrocyte sickling was measured in a reaction-limited system and the effect of pH, 2,3-DPG, and alkylureas on the rate of sickling was studied. Cells were subjected to sudden deoxygenation with sodium dithionite in a rapid-reaction parallel plate flow channel and individually tracked in time on video-tape. The time at which 50% of the originally discoidal cells sickled (t50) was measured. AS and SC cells demonstrated progressively decreased sickling times when the pH was lowered from 7.4 to 6.8. In contrast, there was little effect on the t50 of SS cells, unless the cells were in hypotonic medium. Metabolically induced decreases in red cell 2,3-DPG markedly increased the sickling times of SS cells. Alkylureas increased the t50 of SS cells 50% at 0.1 molar concentration. At 0.01 molar concentration no effect on the rate of sickling was observed. Alterations in sickling kinetics may be used in studying the effect of physiologic compounds and drugs on the sickling process.
Of Mice and Other Complaints

First Complaint: Drawn as I am to personal essays, I lose patience with those seductively titled by the subject they purport to address, Uke "anger" or "art" (the same thing?), when they're really just an excuse for a writer to talk about herself. It's a coy trick indeed, sneaking up on the reader Uke that in one guise, with the writing winking to say, "You know and I know it's not really 'education' or 'solitude' she has under those clothes . . . ." In defense of personal essays, of course, a form I madly envy, the reaUy good ones are not just self-indulgences, but expos?s of all those Uttle holes in the larger fabric of what we call universaUty. A good essay lets in a little light at a time.
A Hybrid Rough K-Means Algorithm and Particle Swarm Optimization for Image Classification

This paper proposes a hybrid rough K-means algorithm for image classification. The rough set theory is used to establish the lower and upper bound for data clustering in the K-means algorithm. Then, the particle swarm optimization (PSO) is employed to optimize the solutions of the rough K-means algorithm. The combined algorithm is called the Rough K-means PSO algorithm. Experimental results show that the proposed algorithm performs better and improves the classification in the blurred and vague areas of test images.
Perseveration and problem solving in infancy.

Publisher Summary This chapter summarizes research that has been conducted on the perservative responses of infants aged 6.5 to 11 months in a variety of tasks. It presents a model of infant perseveration in nonmemory-and-motor tasks, reviews evidence from support and containment tasks that supports this model, and examines how this model could be extended to account for infant perseveration in more traditional memory-and-motor tasks, such as delayed search tasks. Although obviously preliminary and in need of greater elaboration and refinement, it is believed that the approach holds great promise. First, it helps place infant perseveration in the broader context of human problem solving, and brings to light striking continuities in infants' and adults' responses to repeated events and problems. Second, it makes clear that a full account of infants' responses to events and problems will require detailed analyses of the contents of infants' representations in specific task situations, and the changes that take place in these representations as infants acquire expertise at the tasks.
NEGOTIATING TRADITION Tourism Retailers in Guatemala

Abstract Retailers serve as intermediaries between artisans and tourist consumers in the marketing of textile and craft products. This study examines the role of intermediaries by exploring retailers' perceptions of tradition as they contemplate, blend, and juxtapose textile product features for a tourism market. Qualitative research methods were employed to collect data. A related group of product characteristics emerged as being salient to defining Guatemalan textile traditions, including techniques, function and meaning, and tools and equipment. Retailers also conceptualized tradition in terms of concrete and abstract continua that guided their direct and theoretical decisions and served as a basis of negotiation concerning their products and businesses.
Huntington's disease: silencing a brutal killer.

Huntington’s disease (HD) is a progressive and invariably fatal autosomal dominant neurodegenerative disorder caused by expansion of the CAG repeat in exon 1 of the Huntingtin gene. CAG repeat expansion generates an extended, toxic polyglutamine tract in the mutant Huntingtin protein (The Huntington’s Disease Collaborative Research Group, 1993), which disrupts a stunningly large number of cellular pathways. Mutant Huntingtin is especially damaging to the medium spiny neurons of the striatum (Graveland et al., 1985), and degeneration in this region is thought to underlie the motor disturbances or —chorea that characterize the disease. In parallel, loss of striatal and cortical neurons disrupts patient cognition and alters mood and personality (Heinsen et al., 1994). The age of onset of HD varies with CAG repeat length (Brinkman et al., 1997; Duyao et al., 1993) 36 or more repeats is considered pathological, but some patients with 36 to 39 repeats remain asymptomatic well into old age. The vast majority of patients are heterozygous for the HD mutation; most have 39 to 50 repeats and develop symptoms between age 30 and 50. No current treatment can prevent or delay the progression of HD.
Thermal panting in domestic pigeons, Columba livia , and the barn owl, Tyto alba

The respiratory frequency and gular flutter frequency of 12 domestic pigeons and one barn owl were determined during exposure to air temperatures of 35–50 ° C. In both species respiratory and gular flutter frequencies increased with increasing body temperature (Tb) until maximum rates were obtained (Figs. 1, 4). In pigeons, the increase in respiratory frequency was preceded by a 0.5–1.4 ° C rise inTb. Gular flutter and panting occurred synchronously (Fig. 2), and mean maximum and minimum flutter rates were significantly different in the pigeon. These results demonstrate that under moderate thermal loads pigeons, and perhaps barn owls, do not pant at the resonant frequency of the respiratory system.
Abdominal injuries in restrained pediatric passengers

A statewide experience with pediatric abdominal visceral injury in restrained automobile passengers was compiled from the trauma registries of two academic institutions. Retrospective analysis of motor vehicle passenger injuries from 1987 to 1991 included age, sex, mechanism of injury, prehospital care, type of injury, therapeutic interventions, complications, and ultimate outcome. The records of over 2,000 patients evaluated for blunt trauma were reviewed, with 42 children fulfilling the following inclusion criteria: 15 years of age or younger, restrained in an automobile at the time of the accident, and diagnosed with an abdominal injury. Of the 42 patients studied, there were 20 boys and 22 girls; ages ranged from 2 months to 15 years (mean, 7.02 years). Six of 42 patients (14%) required extrication from the vehicle at the scene. Nineteen of 42 patients (45%) sustained belt-related abdominal wall bruising or erythema. The specific blunt visceral injuries noted were as follows: splenic 5, hepatic 5, bowel 6, renal 3, combined 6 (stomach, diaphragm, pancreas, or retroperitoneum). Twenty-three children (55%) had abdominal visceral injuries without external seat belt marks. Operative intervention was necessary in seven patients. A delay in diagnosing visceral injury occurred in 4 of 42 (10%) cases. One patient developed abdominal symptoms 72 hours after the accident. Length of hospital stay ranged from 1 to 45 days. Complications occurred in 4 (10%) of patients. There were two deaths due to injuries. Hollow and solid visceral injuries can occur in belted pediatric passengers during vehicular accidents. Both are a source of significant morbidity, and the patient should be evaluated carefully.(ABSTRACT TRUNCATED AT 250 WORDS)
Adaptive computer technology: An overview

The use of computers in many areas of daily life is now a fact. Banking, sales, transportation, education, and recreation are all influenced by the use of computers. The distinction between “adaptive” and “normal” equipment is breaking down as the objective of “user friendliness” becomes the accepted technology standard. A current tenet of microcomputers is that the friendliness of a computer has more to do with sophistication of the hardware and software than the physical condition of the user. As we move into the twenty‐first century, old concepts of competence, independence, intelligence, and freedom may be put aside in favor of ideals that will empower everyone.
DEVELOPMENT OF A SYSTEMS PERSPECTIVE FOR LONG DURATION SPACE FLIGHT MISSIONS USING A CREW SYSTEMS INTERACTIONS MODEL (CSIM)

The confinement and isolation of the crew of a long duration manned space flight mission such as the planned International Space Station or proposed expeditions to the Moon or Mars cause the social environment and the crew capabilities and limitations to be extremely influential to mission success. The systems engineering process must be executed within the constraints imposed by the system environment (including the social, technical, economic, and political (STEP) factors) as well as those constraints imposed by the personnel who must design, operate, and maintain the system. This process could be facilitated if the diverse sociological and psychological models were integrated to define a set of requirements for spacecraft design and criteria for crew selection and training. A Crew/System Interactions Model (CSIM) is presented as a tool for synthesizing and linking psychological and sociological theories. The CSIM would serve as a reference for improving and refining the causal relationships describing effects of crew actions and behaviors on the system, allowing the development of design criteria that are better tailored to the mission needs and operational requirements.
Psychosomatic disorders: psychotropic medications.

Abstract Psychiatric consultation in the management of the patient with psychosomatic disorders often occurs during a de terioration in the patient's clinical course. It is the task of the consultant to use the tools at his disposal to help the patient move toward more adaptive functioning. Often supportive care and brief psychotherapy are sufficient in creating this momen tum. If this intervention does not suffice, the use of psychotropic drugs is indicated. Several specific symptom complexes are dis cussed and recommendations for management are outlined.
Using a computational model of human color vision to perform object segmentation in natural images

Most recent attempts at object segmentation have been based on object motion in video sequences. However, object segmentation in still images is more difficult. Without motion cues, other cues must be found. Edge detection algorithms are able to extract object contours from images, and were once thought to hold promise for object segmentation in still images. However, additional processing is needed to distinguish between object contours and other edges, such as those produced by textures. The alternative method of region growing (based on luminance or color) has also proven rather ineffective for object segmentation in natural images. In contrast, humans are very successful at object segmentation in still images, suggesting that a model of the early human visual system (HVS) might reveal useful methods for more robust object segmentation in still images. The research results presented in this paper are derived from an HVS model that includes models of Type 1 and Type 2 color contrast cells, and double opponent color contrast cells. By combining the outputs of these cells with edge detected images, object contours can be better distinguished from other contours (such as texture contours and shadow contours) thus providing enhanced object segmentation in cluttered images.
Cylindrical Structures in the Chloroplasts of Sirogonium melanosporum

Cylindrical structures with outside diameters of 390 to 410 A have been observed in the chloroplasts of mature vegetative cells of the filamentous, green alga Sirogonium melanosporum. These cylindrical structures are either parallel to one another or randomly oriented in the stroma matrix of the chloroplast. Some of the outer cylindrical structures of the complex appear to be continuous with thylakoid membranes, suggesting a relationship between these two structures.
Laparoscopic suture hysteropexy for uterine prolapse.

Abstract Objective: Vaginal hysterectomy remains the accepted surgical treatment for women with uterine prolapse. The Manchester repair is favored in women wishing uterine preservation. Vaginal hysterectomy alone fails to address the pathologic cause of the uterine prolapse. The Manchester repair has a high failure rate and may cause difficulty sampling the cervix and uterus in the future. The laparoscopic suture hysteropexy offers physiologic repair of uterine prolapse. Method: At the laparoscopic suture hysteropexy, the pouch of Douglas is closed and the uterosacral ligaments are plicated and reattached to the cervix. Results: Forty-three women with symptomatic uterine prolapse were prospectively evaluated and underwent laparoscopic suture hysteropexy with a mean follow-up of 12 ± 7 months (range 6–32). The mean operating time for the laparoscopic suture hysteropexy alone was 42 ± 15 minutes (range 22–121), and the mean blood loss was less than 50 mL. On review, 35 women (81%) had no symptoms of prolapse and 34 (79%) had no objective evidence of uterine prolapse. Two women subsequently completed term pregnancies and were without prolapse. Both underwent elective cesarean delivery. Conclusion: The laparoscopic suture hysteropexy is effective and safe in the management of symptomatic uterine prolapse. The result is physiologically correct, without disfiguring the cervix. This may be an appropriate procedure for women with uterine prolapse wishing uterine preservation.
Effect of food and oral simulating fluids on dentine bond and composite strength

The effect of up to 30 days' immersion in 75% ethanol solution and in an artificial saliva (Moi-Stir) on the dentine shear bond strength (SBS) of three adhesive/composite systems (Tenure/Marathon One, Scotchbond Multi-Purpose/Z100 and Optibond/Herculite XRV) was evaluated. Two control series were stored either in 100% humidity or in air. Diametral tensile specimens (DTS) of the composites studied were stored in 75% ethanol for up to 30 days. The fracture mode and morphology of the failure interface were examined by scanning electron microscopy (SEM). Data were analysed using ANOVA and the Tukey LSD test. The SBS for all systems stored in Moi-Stir (24.8 +/- 3.0 MPa) and air (28.3 +/- 3.0 MPa) was not influenced by length of storage. Microscopic (SEM) examination of the debonded air, and Moi-Stir stored specimens showed that failure had primarily occurred through the dentine. Significant decreases (30-50%) in the SBS of all systems occurred after immersion in 75% ethanol. There was no significant difference among brands. The DTS of the composites showed significant decreases as a function of ethanol exposure. Marathon One and Herculite XRV showed significantly lower DTS after 14 days' storage while Z100 showed no reduction in DTS until after 30 days. The decrease in both SBS and DTS after storage in ethanol was a function of the square root of time (P < 0.001) and followed Fick's laws of diffusion. Ethanol diffusivity was approximated as 1.8 x 10(-6) cm2 s-1 for both SBS and DTS specimens, suggesting that alcohol attack in SBS specimens occurred primarily in the composite system.(ABSTRACT TRUNCATED AT 250 WORDS)
Precursors to engaged leaders in virtual project teams

Virtual project teams are becoming common organizational structures because firms seek to leverage geographically distributed, specialized knowledge to execute work. Performance in virtual teams can be increased through effective leadership. Although a growing body of research exists that identifies how effective leaders engage in interactions with their teams, we know less about how to strategically identify candidates for leadership positions who have high potential to become engaged leaders. Our research fills this gap by exploring how prior experiences can be used to predict engagement in interactions associated with effective leadership. Our research is based on analysis of 20 graduate students in four simulated virtual project teams executing a construction design and planning task. Results suggest that in virtual teams, engagement is conditioned by the technological context in which the work is executed. Our findings have implications for existing leadership training programs and contribute to theories about the appropriateness of shared leadership models for virtual project teams.
The role of membrane patch size and flow in regulating a proteolytic feedback threshold on a membrane: possible application in blood coagulation

Positive feedback controls in proteolytic systems are characterized by thresholds which are regulated by the concentration of the initial stimulus and the kinetic parameters for enzyme generation and inhibition. Significant complexity is added when a positive feedback is localized on a membrane in contact with a flowing medium, such as seen in the early steps of blood coagulation. A partial differential equation model of an archetypal feedback loop is examined in which a proteolytic enzyme catalyzes its own formation from a zymogen on a membrane in contact with a flowing medium. As predicted from prior solution-phase and membrane-phase analyses, the threshold conditions for activation of the system are regulated by the kinetics of enzyme generation and inhibition and by the density of reactant-binding sites on the membrane; but the present analysis also establishes how the feedback threshold is controlled by the flow rate of the adjacent medium and the physical size of the membrane patch on which the feedback loop is localized. For given systems of particular kinetic properties, lower flow rates or larger active patches of membrane can result in the activation threshold being exceeded, whereas higher flow rates or smaller membrane patches can prevent initiation. In addition to numerical simulation, a simplified non-flowing model is analyzed to formulate an approximate mathematical statement of the dependence of the minimum activatable patch size on the kinetic and other parameters.
Phase control of the competition between electronic transitions in a solvated laser dye

Abstract Excited state population can be manipulated by resonant chirped laser pulses through pump–dump processes. We investigate these processes in the laser dye LD690 as a function of wavelength by monitoring the saturated absorption of chirped ultrafast pulses. The resulting nonlinear absorption spectrum becomes increasingly complex as the pulse is tuned to shorter wavelengths. However, fluorescence measurements indicate that the excited state population depends weakly on chirp when the pump wavelength is far from the lowest order electronic transition. Using a learning algorithm and closed-loop control, we find nonlinear chirp parameters that optimize features in the transmission spectrum. The results are discussed in terms of competition between excited state absorption and stimulated resonant Raman scattering.