cssi/SciSciGPT-SciSciNet huggingface dataset:
Computational x-ray crystallography as a signal recovery problem

The goal in x-ray crystallography is to recover a signal from measurements of the magnitude squared of its Fourier transform. We describe a Bayesian statistical approach using a Markov random field model of the signal and a least squared error reconstruction criteria. The key computation is the computation of the a posteriori mean of the Markov random field given the data. We approximate this mean with the cluster approximation and use a continuation method to solve the resulting fixed-point equation. A small numerical example is presented.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Migration of Escherichia coli dnaB protein on the template DNA strand as a mechanism in initiating DNA replication.

Abstract The first step in conversion of ϕX174 singlestranded DNA to the duplex replicative form in vitro is the synthesis of a nucleoprotein intermediate [Weiner, J. H., McMacken, R. & Kornberg, A. (1976) Proc. Natl. Acad. Sci. USA 73, 752-756]. We now demonstrate that dnaB protein (approximately one molecule per DNA circle) is an essential component of the intermediate and retains its ATPase activity. Synthesis of RNA primers, dependent on dnaG protein (primase), occurred only on DNA that had been converted to the intermediate form. In a coupled RNA priming-DNA replication reaction the first primer synthesized was extended by DNA polymerase III holoenzyme into full-length complementary strand DNA. In RNA priming uncoupled from replication, multiple RNA primers were initiated on a ϕX174 circle. The single dnaB protein molecule present on each DNA circle participated in initiation of each of the RNA primers, which appear to be aligned at regular intervals along the template strand. We propose that dnaB protein, once bound to the template, migrates in a processive fashion along the DNA strand, perhaps utilizing energy released by hydrolysis of ATP for propulsion; in this scheme the actively moving dnaB protein acts as a “mobile promoter” signal for dnaG protein (primase) to produce many RNA primers. Schemes are proposed for participation of dnaB protein both in the initiation of replication at the origin of the Escherichia coli chromosome and in the initiation of primers for nascent (Okazaki) fragments at a replication fork.
Constructions of sparse uniform hypergraphs with high chromatic number

A random construction gives new examples of simple hypergraphs with high chromatic number that have few edges and-or low maximum degree. In particular, for every integers k ≥ 2, r ≥ 2, and g ≥ 3, there exist r-uniform non-k-colorable hypergraphs of girth at least g with maximum degree at most ⌈r kr-1 lnk⌉. This is only 4r2 lnk times greater than the lower bound by Erdos and Lovasz (Colloquia Math Soc Janos Bolyai 10 (1973), 609–627) that holds for all hypergraphs (without restrictions on girth). © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Mechanisms for the Impact of Whole Grain Foods on Cancer Risk

Dietary guidance recommends consumption of whole grains for the prevention of cancer. Epidemiologic studies find that whole grains are protective against cancer, especially gastrointestinal cancers such as gastric and colonic, and hormonally-dependent cancers including breast and prostate. Four potential mechanisms for the protectiveness of whole grains against cancer are described. First, whole grains are concentrated sources of dietary fiber, resistant starch, and oligosaccharides, fermentable carbohydrates thought to protect against cancer. Fermentation of carbohydrates in the colon results in production of short chain fatty acids that lower colonic pH and serve as an energy source for the colonocytes. Secondly, whole grains are rich in antioxidants, including trace minerals and phenolic compounds, and antioxidants have been proposed to be important in cancer prevention. Thirdly, whole grains are significant sources of phytoestrogens that have hormonal effects related to cancer protection. Phytoestrogens are thought to be particularly important in the prevention of hormonally-dependent cancers such as breast and prostate. Finally, whole grains mediate glucose response, which has been proposed to protect against colon and breast cancer.
Biomarkers for late-onset neonatal sepsis

The diagnosis of healthcare-associated infections is problematic because of the overlap between clinical signs associated with 'normal' physiological disturbances and those of bacteremia or fungemia. Earlier diagnosis of sepsis in critically ill infants would enable timely administration of antibiotics and discontinuation of treatment in infants with a low probability of sepsis. A recent study by Ng et al. identified two novel biomarkers for late-onset neonatal sepsis: the des-arginine variant of serum amyloid A and apolipoprotein C-II. These markers may be of value in the identification of neonates with bacteremia or fungemia.
Analysis of spin-echo rephasing with pulsatile flow in 2D FT magnetic resonance imaging.

The effects of pulsatile flow on spin phases in spin-echo magnetic resonance imaging are considered. General expressions for the spin phases of the first four echoes are derived in terms of the Fourier coefficients of flow. These expressions are valid for any time-dependent acceleration and, hence, are not restricted to constant acceleration. The derived expressions are then theoretically evaluated for aortic flow and examined at different points in the cardiac cycle. Our results show that rephasing may occur at certain points in the cardiac cycle for either even or odd echoes depending upon the particular Fourier coefficients of the velocity function and the spin-echo delay time. However, even-echo rephasing is not always necessarily valid. Furthermore, the possibility of determining the flow velocities in the body with an appropriate series of imaging studies is also discussed. © 1987 Academic Press, Inc.
Professional Development Needs and Practices among Educators and School Psychologists.

This chapter discusses research showing that despite the high level of interest in motivation and self-regulation, teachers and school psychologists do not target these variables frequently in their assessment, intervention, or instructional activities.
Social Comparison Choice During Ability Evaluation The Effects of Comparison Publicity, Performance Feedback, and Self-Esteem

Using the rank-order paradigm, the effects of comparison publicity, performance feedback, and self-esteem on ability-related social comparison choices were examined. Subjects chose the highest ranked score less frequently when comparison was expected to be public rather than private, when performance feedback suggested failure rather than success, and when subjects were low rather than high in self-esteem. In contrast to previous reports of a stable tendency for subjects to select first the highest ranked score when the range of scores is unknown, the combination of anticipated public social comparison, low score, and low self-esteem created a preference for this score that was descriptively less frequent than chance. It was argued that these results provide converging evidence for social comparison choices motivated by defensive concerns.
High Thermoelectric Figure of Merit in PbTe Alloys Demonstrated in PbTe–CdTe

PbTe alloys have been the most efficient materials for thermoelectric power generation since the 1950s. In addition to the observed lattice thermal conductivity reduction by alloy scattering, recent efforts targeting electronic-transport enhancement through band structure engineering have demonstrated a design route to achieve extraordinary thermoelectric performance. Guided by these recent results, the current work discusses the influence of alloying CdTe in p-type PbTe where the solubility is strongly temperature-dependent. Beneficial changes to the band structure and effective scattering of phonons are concurrently inferred when the PbTe–CdTe precipitate composite is expected to become a solid solution at high temperature, enhancing the peak thermoelectric figure of merit to ~1.7. This work emphasizes the importance of solid solution alloys of PbTe for thermoelectric power-generation applications and also provides an upper limit of about 1 micrometer to the average distance between interfaces above which phonon scattering by composite interfaces is ineffectual.
Death comes alive; technology and the re‐conception of death

(1997). Death comes alive; technology and the re‐conception of death. Science as Culture: Vol. 6, No. 3, pp. 444-466.
Optimal Binary Prediction for Group Decision Making

We address the problem of optimally forecasting a binary variable for a heterogeneous group of decision makers facing various (binary) decision problems that are tied together only by the unknown outcome. A typical example is a weather forecaster who needs to estimate the probability of rain tomorrow and then report it to the public. Given a conditional probability model for the outcome of interest (e.g., logit or probit), we introduce the idea of maximum welfare estimation and derive conditions under which traditional estimators, such as maximum likelihood or (nonlinear) least squares, are asymptotically socially optimal even when the underlying model is misspecified.
Rapid Determination of Reaction Kinetics with an Automated Microfluidic System

Kinetic information is used to determine the optimal reaction conditions, to successfully scale up a reaction from the laboratory to the pilot plant, and to improve process control. Obtaining accurate kinetics using conventional benchtop equipment and techniques, however, requires numerous experiments and can be complicated by sluggish mixing and heat-transfer rates. To improve the speed and efficiency in gathering reaction kinetics, we present an automated, silicon microreactor system that uses a sequential experimentation framework driven by model-based optimization feedback for online reaction rate parameter determination. The method, based on Information Theory and Bayesian Statistics, first selects the appropriate global reaction rate expression. After determining the correct rate law, a D-optimal strategy precisely estimates the pre-exponential and activation energy of the rate constant. The approaches are validated experimentally with a model system, the Diels−Alder reaction of isoprene and maleic ...
The therapeutic treatment provided in cases involving physical child abuse: a description of current practices

Objective: The purpose of this study was to explore the therapeutic treatment provided by mental health practitioners in cases involving physical child abuse to describe generally the amount and type of treatment provided to the abused child and other significant people involved in the abuse. Method: An instrument was designed to determine what therapeutic treatment was provided by practitioners in the previous year and sent to 689 mental health workers in the state of Kentucky: Licensed Clinical Social Workers, Clinical Members of the American Association of Marriage and Family Therapists, and Kentucky Department of Social Services Caseworkers. Results: The family was seen as the primary client most frequently with the focus of therapy being to provide a safe environment for the child or to improve family relationships. Abused children were found to receive only seven of the 23 sessions generally provided in these cases to overcome the deleterious effects of the abuse. Conclusions: The findings indicate that physically abused children may need more treatment to overcome their traumatic experiences. Since the family and the perpetrator have therapeutic requirements, these services need to be additional sessions. While the safety of the child is of paramount importance, the victim needs appropriate and effective treatment to surmount the detrimental consequences of the maltreatment.
Interaction of poly C with cis‐ and trans‐diamminedichloroplatinum (II): Secondary structure effects

The interactions of the ribonucleotide poly C with cis- and trans-diamminedichloroplatinum (II) were probed with Raman spectroscopy. Both platinum compounds attack the N-1 position of the cytosine residue, while the trans form appears to attack the PO2− as well. Raman difference spectra obtained from samples of poly C containing similar amounts of the respective Pt compounds indicate that the trans form is able to disrupt the secondary structure of poly C to a greater degree than the cis form. This latter observation may be a contributing factor in the low therapeutic index exhibited by the trans form.
Abusive Supervision and Employee Outcomes: The Influence of Contract Violation and PsyCap

In this paper, we focus on recent work that has found that when subordinates are abused by their supervisors, they are likely to retaliate against the organization and/or organizational members by ...
Importance of contouring the cervical spine levels in initial intensity-modulated radiation therapy radiation for head and neck cancers: implications for re-irradiation

Aim: To evaluate the maximum differential cervical spinal (C-spine) cord dose in intensity-modulated radiation therapy (IMRT) plans of patients undergoing radiotherapy for treatment of head and neck cancer. Materials and Methods: The C-spine of ten head and neck cancer patients that were planned using IMRT and each cervical vertebral body and the right and left sides was contoured by splitting the cord in the center. Dose-volume histograms (DVH) and maximum point doses were obtained for each contour and compared. Results: The dose to the cord varied with the location of the primary tumor but such variation was not consistently seen. This report provides information that is critical for planning reirradiation treatments. We recommend that contouring of the C-spine cord with IMRT should include outlining of each cervical cord level and identification of the right and the left sides of the cord on each plan.
Mechanisms of active and passive rifting

Abstract In this paper we obtain two solutions relating to the alternative active and passive hypotheses for continental rifting. Active rifting assumes the impingement of a mantle plume on the base of the continental lithosphere. We determine the rate of lithosphere thinning due to this impingement. We conclude that it takes 50–75 million years to thin the continental lithosphere to the base of the crust; the long length of time required appears to rule out this lithospheric erosion mechanism as a viable mechanism for complete lithospheric thinning. We suggest that diapiric penetration is the mechanism by which hot mantle rock reaches the base of the continental crust at a rift. We have also obtained values for the tensional stresses generated by the diapiric penetration of hot asthenospheric rock into the lithosphere. The stress levels are obtained as functions of lithospheric and crustal thinning factors. These stresses may lead to rift propagation and the splitting of a continent.
A Study of Symptom Distress, Health locus of Control, and Coping Resources of Aging Post-Polio Survivors

Nearly one-half of the estimated 1.63 million American patients who survived the polio epidemics of the 1940s and 1950s are re-experiencing symptoms of the acute illness. This exploratory study of 125 aging post-polio survivors examined the differences of symptom distress, health locus of control, and coping resources for survivors who had and those who had not incurred a chronic physical disability following the acute phase of poliomyelitis. The Symptom Rating Test, the Multidimensional Health locus of Control Scale, and the Coping Resources Inventory were used. No significant differences were found between disability groups concerning symptom distress, health locus of control, or coping resources. However, significant negative correlations were found between coping resources and both the quantity and severity of symptom distress. The differences found between perceived health locus of control and both coping resources and symptom distress were marginally significant.
Regulation of HIV-1 Transcription in Activated Monocyte Macrophages

DNA-binding and functional assays examined the role played by NF-IL6 in regulation of HIV-1 transcription in human monocyte/macrophages (U937 cells), stimulated with LPS+PMA. When incubated with nuclear extracts from stimulated cells, a region (-189/-147), containing the major NF-IL6-binding sequence and the USF site, interacted selectively with USF1 and USF2. Anti-C/EBPbeta reacted poorly with the complexes produced with the wild-type probe. In contrast, complex formation with NF-IL6 was clearly evident in experiments analyzing a probe containing an insertion in the USF site. In functional assays, increasing concentrations of a decoy against NF-IL6 reduced gene expression from the LTR of the wild-type HIV-1 variant, supporting a critical role for NF-IL6 in regulation of HIV-1 transcription in stimulated monocyte/macrophages. The decoy also reduced gene expression from a deletion construct lacking NF-IL6-binding sequences. The results implied that in LPS+PMA-stimulated monocyte/macrophages, the endogenous NF-IL6 could act via a site-independent pathway in upregulation of HIV-1 transcription. Analysis of a short DNA segment, containing the -189/-147 region, suggested functional interactions of NF-IL6 and USF. In activated cells exogenous NF-IL6 enhanced dramatically gene expression through a short DNA segment containing the NF-kappaB sites, supporting functional interactions of NF-IL6 and NF-kappaB.
Adenovirus-mediated Gene Transfer of a Heat Shock Protein 70 (hsp70i) Protects Against Simulated Ischemia ☆

We have recently shown that the overexpression of a heat shock protein 70 (hsp 70) in a rat myogenic cell line confers protection against simulated ischemia. We also developed and demonstrated that overexpression of this protein, in the hearts of transgenic mice, protects against ischemia/reperfusion injury. We have now inserted the hsp70 gene in an adenoviral vector and show that we are able to transfer and achieve overexpression of this protein in neonatal cardiomyocytes and in the rat myogenic cell line H9c2. We find that cells infected with the adenoviral-hsp70i construct are rendered tolerant to simulated ischemia as compared to cells infected with a control recombinant adenoviral construct. In conclusion, our results demonstrate the feasibility of using adenoviral vectors to overexpress the hsp70 in myogenic cells, specially in cardiomyocytes, and the efficiency of this approach for providing protection against myocardial ischemia.
The spectrum of liver and spleen injuries in children: failure of the pediatric trauma score and clinical signs to predict isolated injuries.

Study objectives: To determine whether potentially life-threatening intra-abdominal injuries occur in the absence of multisystem trauma in children, and to determine the usefulness of physical examination and a pediatric triage score in the assessment of liver and spleen injuries in children. Design: Retrospective study. Setting: Admissions to a children's hospital from October 1982 through September 1989 who were found to have liver or spleen injuries. Seventy-seven patients were identified; 55 were male, 22 were female. Mean age was 9 years and 3 months (± 56 months) with a range of 22 months to 20 years, 4 months. Clinical signs were recorded and a Pediatric Trauma Score (PTS) and Injury Severity Score (ISS) were calculated for each patient. Measurements and main results: Fifty-four patients (70%) had a spleen injury, 18 (23%) had a liver injury, and five (7%) had both liver and spleen injuries. Patients were managed without surgery in 63 of 77 cases (82%); two died. Fifty-one of 77 patients (66%) received an ISS of 18 or less; 26 patients (34%) received a score of more than 18. Forty-four of the 51 patients (86%) with an ISS of 18 or less had a normal pulse (120 or less); 48 of the 51 (94%) had a normal systolic blood pressure (90 mm Hg or more). A strong negative correlation ( r = −0.80; P = .001) was found between the two scores for children with multiple severe injuries (ISS of more than 18); there was poor correlation ( r = −0.04; P > .05) between the two scores for isolated liver or spleen injury (ISS of 18 or less). Conclusions: We conclude that liver or spleen damage may be present in children without other injuries and must be considered with a high index of suspicion, and that neither the initial clinical findings nor the PTS reliably predicts liver or spleen injuries in children with focal abdominal injuries.
Supporting Non-Tenure-Track Faculty at 4-Year Colleges and Universities: A National Study of Deans' Values and Decisions.

This study examines the values held by 264 academic deans and the decisions they make pertaining to supporting non-tenure-track faculty (NTTF). Multiple analyses are utilized to examine the prevalence of supportive policies for both full- and part-time NTTF, as well as the extent to which deans’ values are associated with the existence of these policies on college and university campuses. Findings reveal that deans’ values play a significant role in organizational decisions to support NTTF, and part-time faculty remain under-supported in the academy. Implications for practice are discussed.
Temperature dependence of nuclear spin-lattice relaxation in the heavy-fermion superconducting state

Abstract Some features of the experimental data on nuclear spin relaxation time T 1 in the heavy-fermion superconducting state can be explained by taking into account the effect of the electron Zeeman energy. It is found that at intermediate temperatures the usual quasiparticle spin-flip scattering dominates, while at very low temperatures a new process, pair creation (annihilation), dominates and gives T -1 1 ∝ T .
Direct inhibition of the NOTCH transcription factor complex

Direct inhibition of transcription factor complexes remains a central challenge in the discipline of ligand discovery. In general, these proteins lack surface involutions suitable for high-affinity binding by small molecules. Here we report the design of synthetic, cell-permeable, stabilized α-helical peptides that target a critical protein–protein interface in the NOTCH transactivation complex. We demonstrate that direct, high-affinity binding of the hydrocarbon-stapled peptide SAHM1 prevents assembly of the active transcriptional complex. Inappropriate NOTCH activation is directly implicated in the pathogenesis of several disease states, including T-cell acute lymphoblastic leukaemia (T-ALL). The treatment of leukaemic cells with SAHM1 results in genome-wide suppression of NOTCH-activated genes. Direct antagonism of the NOTCH transcriptional program causes potent, NOTCH-specific anti-proliferative effects in cultured cells and in a mouse model of NOTCH1-driven T-ALL. The NOTCH complex is of tremendous interest because of its role as a master developmental regulator of gene transcription, a substrate for γ-secretase and an oncogene inappropriately activated in many cancers including T-cell leukaemias. Like the majority of transcription factors, NOTCH was thought to be untargetable by synthetic cell-permeable molecules. But now a promising NOTCH antagonist has been designed, and found to be effective in reducing leukaemia growth in a mouse model. The hydrocarbon-stapled peptide SAHM1 acts by preventing assembly of the active transcriptional complex, providing a potentially valuable tool for studies of the role of NOTCH and a starting point for therapeutic agents. In addition, the direct targeting of transactivation complexes may be applicable to several other transcription factor complexes previously considered untargetable. It is notoriously difficult to target transcription factors with aberrant activity in cancer. Inappropriate activation of the NOTCH complex of transcription factors is directly implicated in the pathogenesis of several disease states, including T-cell acute lymphoblastic leukaemia. The design of synthetic, cell-permeable, stabilized α-helical peptides that disrupt protein–protein interactions in NOTCH is now described.
DETERMINING A SUSTAINABLE APPROACH FOR MANAGING AN ESTUARY MOUTH - A CASE STUDY

Estuaries and their floodplains represent locations where significant population, industry and environmental interests exist. Sand spits located at estuary mouths are one factor in influencing both hydrodynamics and geomorphology. As such, their management is important as regards managing both flood and coastal risk, and the evolution of designated flora and fauna. This paper describes a study to develop a way forward for managing Dawlish Warren sand spit, located at the mouth of the Exe Estuary in Devon, UK. Dawlish Warren sand spit is important as it influences geomorphological evolution of the mouth and wider estuary, provides storm sheltering for up to 2,900 properties and national transport infrastructure in the estuary, is an internationally designated Special Area of Conservation (SAC), and influences the wider Exe Estuary Special Protection Area (SPA).
Ribonucleases May Limit Recovery of Ribonucleic Acids From Archival Human Temporal Bones

Messenger ribonucleic acid (mRNA) for actin was detected in celloidin-embedded archival human temporal bone sections with reverse transcription polymerase chain reaction (RT-PCR). Actin mRNA was detected in 10% of sections analyzed. One possible reason for this modest detection incidence is enzymatic degradation of RNA by exogenously introduced ribonucleases (RNases). We have identified steps of the temporal bone processing protocol for archival storage in which exogenous RNases could be introduced to the tissue, and have verified that the bone sections are exposed to these enzymes. We have demonstrated that implementing precautions to minimize exogenous RNase contamination during processing improves recovery of intact RNA. This study indicates that although gene expression analysis of archival human temporal bones may be limited by enzymatic degradation of RNA, simple modification of processing protocol can improve yield of informative data.
Perforated duodenal ulcer associated with ovarian hyperstimulation syndrome: Case Report

Ovarian hyperstimulation syndrome (OHSS) remains the most serious medical complication of controlled ovarian stimulation. An unusual case of perforated duodenal ulcer following critical OHSS is presented. A 29 year old nulligravid woman with polycystic ovarian syndrome underwent her first attempt at in-vitro fertilization. She was admitted to the hospital with critical OHSS and subsequently found to have a perforated posterior duodenal ulcer. She underwent exploratory laparotomy, antrectomy and gastrojejunostomy. Pathological analysis of her gastric antrum confirmed chronic gastritis and Helicobacter pylori. She required prolonged assisted ventilation, vasopressor support, multiple i.v. antibiotics, blood product replacement and nutritional support. The patient was hospitalized for a total of 47 days and then transferred to a rehabilitation facility for an additional 30 days before being discharged to home. In this critically ill patient with OHSS, severe stress associated with invasive monitoring and multiple medical therapies in the intensive care unit as well as H. pylori infection appear to be the most probable causative factors of her perforated viscus. Prompt recognition of potential complications and proper medical intervention are essential in the management of patients with OHSS. Avoidance strategies are still needed.
The Probability That Random Positive Integers Are 3-Wise Relatively Prime

A list of positive integers are 3-wise relatively prime if every three of them are relatively prime. In this note we consider the problem of finding the probability that k positive integers are 3-wise relatively prime and give an exact formula for this probablility.
Spectroscopic and ligand-binding properties of an oxygen-binding heme protein from Chromatium vinosum

Magnetic circular dichroism spectra were obtained for the oxidized and reduced forms of cyanide, azide and carbon monoxide complexes of an O2-binding hemeprotein isolated from the photosynthetic purple sulfur bacterium, Chronatium vinosum. Cyanide binding to the protein, which results in formation of a low-spin complex, was highly pH dependent with little complex formation observed at pH values near or below 7.
A method to correct for scatter, spillover, and partial volume effects in region of interest analysis in PET

Scatter and spatial resolution effects degrade the accuracy of radioactivity concentration estimates obtained from positron emission tomography (PET) data. The authors present and evaluate a methodology for region quantification which accounts for these degradations. The method is based on analysis of sinogram data and does not require dynamic data sequences to be reconstructed. Moreover, estimates of region variance are also produced which may be used to define weights for model analyses that use weighted least squares minimization in order to obtain unbiased parameter estimates. The authors evaluate the method using both simulation and measured data and find that, with an appropriate model of scatter and spatial resolution effects, it is unbiased and capable of quantifying myocardial concentration with no more than a 5% error in accuracy for myocardium as thin as 10 mm.
PROTEIN COAGULATION AND ITS REVERSAL : SERUM ALBUMIN

1. It is possible to prepare crystalline, soluble, heat-coagulable serum albumin from coagulated serum albumin. 2. In the cases so far studied, the more soluble a denatured protein, the more easily its denaturation can be reversed.
Biliary tract complications after liver transplantation

Biliary tract complications are an important source of morbidity after liver transplantation, and present a challenge to all involved in their care. With increasing options for transplantation, including living donor and split liver transplants, the complexity of these problems is increasing. However, diagnosis is greatly facilitated by modern noninvasive imaging techniques. A team approach, including transplant hepatology and surgery, interventional endoscopy and interventional radiology, results in effective solutions in most cases, such that operative reintervention or retransplantation is rarely required.
Some critical tribological issues in contact and near-contact recording

Critical tribological issues concerning contact and near-contact recording arise naturally as an extension of similar concerns for conventional air bearing recording systems. Issues of surface conformity, spacing variation, and impact response become even more important in light of the smoother surfaces and more restrictive magnetic spacing requirements. The authors present results of studies in these areas. First, they consider the friction variation around a track of a read-write head sliding in contact with a thin film disk. A measure of conformity is sought between the surfaces whose variation will correlate with the friction variation. Next, the authors study some important issues related to spacing variation for flying sliders by measurement and simulation. Finally, the slider dynamics associated with asperity contact is simulated for advanced sliders. >
Developing the evidence for evidence-based practice.

In this issue of CMAJ , Deshauer and colleagues[1][1] note that most (93%) trials of drugs for the treatment of depression last less than 6 months (typically 6–8 weeks); indeed, most are conducted for registration purposes by industry. Despite the widely accepted view that depression is chronic or
TAXONOMY OF PSEUDOMONAS PISCICIDA (BEIN) BUCK, MEYERS, AND LEIFSON.

Abstract Hansen, A. J. (University of Idaho, Moscow), O. B. Weeks, and R. R. Colwell. Taxonomy of Pseudomonas piscicida (Bein) Buck, Meyers, and Leifson. J. Bacteriol. 89:752–761. 1965.—Twenty strains of marine bacteria showing the properties of pigmentation and icthyotoxicity were studied for selected physiological features. A quantitative taxonomic analysis with an electronic computer was performed. Eighteen species of Pseudomonas were included in the computer analysis as reference strains. The marine collection formed a homogeneous cluster, 80% similarity, and showed a 67 to 70% similarity to certain of the Pseudomonas species: P. atlantica, P. geniculata, P. synxantha, and P. taetrolens. The marine strains are treated as a phenon describing the species P. piscicida. The species was characterized by the hypothetical Median Organism concept; P. piscicida 14 corresponded most closely to the Median Organism.
Sensation thresholds for vibrotactile information transfer

The authors present results of determining sensation thresholds to vibration waveforms in a range of frequencies and duty cycles for vibrotactile information transfer applied to the visually handicapped. The stimulation waveform is composed of an excitatory part, i.e. a burst of rectangular pulses, and a recovery time, i.e. a period of no stimulation, to minimize adaptation. Several subjects were tested, all giving similar threshold curves. The results make it possible to determine a combination of parameters that permits optimization of sensation with minimization of power delivered. >
Computer aided human-machine interface design

Computer generated models of three dimensional mannequins can be used to visually and objectively analyze the human fit to the equipment being designed. A computer program has been developed which runs under an AutoCAD platform and enables users to conduct evaluations of human fit from the early stage of design. The program is useful in both classroom demonstrations and industrial applications. The program features are described and its application illustrated with an example.
Limitations to estimating bacterial cross‐species transmission using genetic and genomic markers: inferences from simulation modeling

Cross-species transmission (CST) of bacterial pathogens has major implications for human health, livestock, and wildlife management because it determines whether control actions in one species may have subsequent effects on other potential host species. The study of bacterial transmission has benefitted from methods measuring two types of genetic variation: variable number of tandem repeats (VNTRs) and single nucleotide polymorphisms (SNPs). However, it is unclear whether these data can distinguish between different epidemiological scenarios. We used a simulation model with two host species and known transmission rates (within and between species) to evaluate the utility of these markers for inferring CST. We found that CST estimates are biased for a wide range of parameters when based on VNTRs and a most parsimonious reconstructed phylogeny. However, estimations of CST rates lower than 5% can be achieved with relatively low bias using as low as 250 SNPs. CST estimates are sensitive to several parameters, including the number of mutations accumulated since introduction, stochasticity, the genetic difference of strains introduced, and the sampling effort. Our results suggest that, even with whole-genome sequences, unbiased estimates of CST will be difficult when sampling is limited, mutation rates are low, or for pathogens that were recently introduced.
EPR studies on hydroxyl radical-scavenging activities of pravastatin and fluvastatin

Statins are known clinically by their cholesterol reduction properties through the inhibition of HMG-CoA reductase. There is mounting evidence suggesting a protective role of statins in certain types of cancer, cardiac, and vascular disease through a mechanism that extends beyond their lipid lowering ability. The root mechanism of damage likely involves the inflammatory cascade, specifically compounds known as reactive oxygen species such as the hydroxyl radical. However, direct evidence for the hydroxyl-scavenging capacity of pravastatin and fluvastatin, two forms of statins being widely used to lower LDL cholesterol, is still lacking in literature. In this study, electron paramagnetic resonance spectroscopy in combination with 5,5-dimethyl-1-pyrroline N-oxide (DMPO)-spin-trapping technique was utilized to determine the abilities of pravastatin and fluvastatin in scavenging hydroxyl radical generated from Fe(II) with H2O2 system. In addition, we examined the effects of pravastatin and fluvastatin on oxidative-induced φX-174 RF I plasmid DNA damage. We have demonstrated here for the first time that pravastatin and fluvastatin at physiologically relevant concentrations significantly decreased formation of DMPO-OH adduct indicating that both compounds could directly scavenge hydroxyl radicals. However, pravastatin and fluvastatin were not able to directly protect against oxidative DNA plasmid damage. The hydroxyl radical sequestering ability of pravastatin and fluvastatin reported in this study may contribute to their beneficial use in certain types of cancer and in cardiovascular disease.
Intraoperative evaluation of sentinel lymph nodes for metastatic melanoma by imprint cytology.

BACKGROUND Sentinel lymph node (SLN) biopsy has revolutionized lymph node staging in patients with malignant melanoma. Intraoperative evaluation is a new addition to the SLN procedure that allows for a one-step regional lymph node dissection to be performed when the SLN biopsy findings are positive. To date, several studies have evaluated the use of intraoperative frozen sectioning to evaluate the SLN in patients with melanoma. The literature pertaining to the use of intraoperative imprint cytology (IIC) to evaluate the SLN in melanoma patients is scant and to the authors' knowledge studies published to date are relatively small. The purpose of the current study was to evaluate the utility of IIC in patients undergoing SLN for melanoma. METHODS A total of 235 SLN biopsies from 93 patients with malignant melanoma and 3 patients with atypical Spitz nevi were examined by IIC after SLN biopsy using a double indicator technique. The SLNs were bisected and a pair of imprints were made from each half. One imprint from each half was stained with hematoxylin and eosin (H & E) whereas its counterpart was stained with Diff-Quik. Paraffin-embedded permanent sections were examined using multiple H & E stained sections from the SLNs in conjunction with immunohistochemical staining for S-100 and HMB-45 proteins. RESULTS A total of 235 SLNs were excised from 93 patients (2.5 SLNs per patient). On a per patient basis, metastases were identified in 21 patients (23%) on permanent section evaluation. Of these 21 patients, 8 were detected by IIC (sensitivity of 38%). The negative predictive value was 85%. No false-positive results were identified (specificity of 100%). The positive predictive value was 100%. The overall accuracy of the intraoperative evaluation was 86%. Patients found to have positive SLNs by IIC went on to undergo lymphadenectomy under the same anesthetic. CONCLUSIONS The sensitivity and specificity of IIC are similar to those of intraoperative frozen-section evaluation. Therefore, IIC appears to be a viable alternative to frozen sectioning when intraoperative evaluation is required. IIC evaluation of SLN makes a single surgical procedure possible for patients with malignant melanoma who are undergoing SLN. Cancer 2002;94:3016–22. © 2002 American Cancer Society. DOI 10.1002/cncr.10512
A Bayesian estimator of protein–protein association probabilities

Summary: The Bayesian Estimator of Protein–Protein Association Probabilities (BEPro aff3) is a software tool for estimating probabilities of protein–protein association between bait and prey protein pairs using data from multiple-bait, multiple-replicate, protein liquid chromatography tandem mass spectrometry LC–MS/MS affinity isolation experiments. Availability: BEPro 3 is public domain software, has been tested on WIndows XP, Linux and Mac OS, and is freely available from http://www.pnl.gov/statistics/BEPro3. Contact: ds.daly@pnl.gov Supplementary Information: A user guide, example dataset with analysis and additional documentation are included with the BEPro 3 download.
Demonstration of vector velocity estimation with airborne SAR-GMTI

The combination of synthetic aperture radar and space-time adaptive processing for airborne moving target indication radar allows the use of long, potentially sparse arrays, wide bandwidths, and long coherent processing intervals (CPIs), all of which enable detection of a greater variety of targets than is possible with traditional systems. By exploiting the blurring effect of moving targets in SAR imagery, both components of target velocity may be simultaneously estimated in each CPI using this scheme. This approach to vector velocity estimation is demonstrated using data from an experimental 12-channel UHF airborne radar developed by MIT Lincoln Laboratory.
The use of the lingual arch in the mixed dentition to resolve incisor crowding

In the mixed dentition, arch length preservation, maintaining the leeway space, can often provide adequate space to resolve lower incisor crowding. Yet the frequency of this occurrence is not known. To obtain this information, lingual arches were placed in the mandibular arches of 107 consecutive mixed dentition patients with incisor crowding to preserve arch length and make the leeway space available to resolve the crowding. Arch length decreased only 0.44 mm whereas the intercanine, interpremolar, and intermolar dimensions increased between 0.72 and 2.27 mm. There was adequate space to resolve the crowding in 65 (60%) of the 107 patients. If perfect arch length preservation had occurred, there would have been adequate space to resolve the crowding in 73 (68%) of the 107 patients. The correlation between leeway space and tooth size-arch size discrepancy was only 0.44.
Comparative evaluation of Symbolic Dynamic Filtering for detection of anomaly patterns

Symbolic Dynamic Filtering (SDF) has been recently reported in literature as a pattern recognition tool for early detection of anomalies (i.e., deviations from the nominal behavior) in complex dynamical systems. This paper presents a comparative evaluation of SDF relative to other classes of pattern recognition tools, such as Bayesian Filters and Artificial Neural Networks, from the perspectives of: (i) Anomaly detection capability, (ii) Decision making for failure mitigation and (iii) Computational efficiency. The evaluation is based on analysis of time series data generated from a nonlinear active electronic system.
Performance optimization for state machine replication based on application semantics

Application semantics are essential in engineering highly dependable systems.Classification for performance optimization approaches to state machine replication.Outline future research directions for high performance dependable systems. The pervasiveness of cloud-based services has significantly increased the demand for highly dependable systems. State machine replication is a powerful way of constructing highly dependable systems. However, state machine replication requires replicas to run deterministically and to process requests sequentially according to a total order. In this article, we review various techniques that have been used to engineer fault tolerance systems for better performance. Common to most such techniques is the customization of fault tolerance mechanisms based on the application semantics. By incorporating application semantics into fault tolerance design, we could enable concurrent processing of requests, reduce the frequency of distributed agreement operations, and control application nondeterminism. We start this review by making a case for considering application semantics for state machine replication. We then present a classification of various approaches to enhancing the performance of fault tolerance systems. This is followed by the description of various fault tolerance mechanisms. We conclude this article by outlining potential future research in high performance fault tolerance computing.
Women in IT: The Endangered Gender

Information technology (IT) careers continue to grow and yet the number of women in them continues to decline. The gap is even more profound in leadership positions. This paper is a review of existing literature, information and statistics concerning women in higher education information technology leadership. It is a call for recruitment, professional development, and retention aimed at helping women overcome systemic exclusion from IT management. It combines the topics of women, higher education, information technology, and leadership and considers them through the lens of professional development and adult education. Finally, it discusses and endorses ideas for initiating change in our field to increase our diversity and therefore meet the growth demands.
Proceedings of the twenty-sixth annual ACM-SIAM symposium on Discrete algorithms

This symposium focuses on research topics related to efficient algorithms and data structures for discrete problems. In addition to the design of such methods and structures, the scope also includes their use, performance analysis, and the mathematical problems related to their development or limitations. Performance analyses may be analytical or experimental and may address worst-case or expected-case performance. Studies can be theoretical or based on data sets that have arisen in practice and may address methodological issues involved in performance analysis.
Redox status in workers occupationally exposed to long-term low levels of ionizing radiation: A pilot study

Objectives: Reactive oxygen species (ROS), including superoxide (O2•−), play an important role in the biological effects of ionizing radiation. The human body has developed different antioxidant systems to defend against excessive levels of ROS. The aim of the present study is to investigate the redox status changes in the blood of radiologic technologists and compare these changes to control individuals.Methods: We enrolled 60 medical workers: 20 occupationally exposed to ionizing radiation (all radiologic technologists), divided in three subgroups: conventional radiography (CR), computerized tomography (CT), and interventional radiography (IR) and 40 age- and gender-matched unexposed controls. Levels of O2•− and malondialdehyde (MDA) in blood were measured as an index of redox status, as were the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase. Redox status was also assessed by measuring levels of reduced and oxidized glutathione (GSH, GSSG, respectively).Results: Levels of O2•...
Where in the World Are the Workers? Cultural Underrepresentation in I-O Research

Few would dispute that the nature of work, and the workers who perform it, has evolved considerably in the 70 years since the founding of the Society for Industrial and Organizational Psychology (SIOP) as the American Psychological Association's (APA's) Division 14, focused on industrial, business, and organizational psychology. Yet, in many ways the populations sampled in industrial–organizational (I-O) psychology research have failed to keep pace with this evolution. Bergman and Jean (2016) highlight how I-O research samples underrepresent (relative to the labor market) low- or medium-skill workers, wage earners, and temporary workers, resulting in a body of science that is overly focused on salaried, professional managers and executives. Though these discrepancies in the nature of individuals’ work and employment are certainly present and problematic in organizational research, one issue that should not be overlooked is that of adequately representing nationality and culture in I-O research samples.
Formation of a pharmacologically active substance from plasma protein.

SummaryEvidence has been presented on formation of a pharmacologically active substance from fraction IV-4 of plasma protein by the action of an α-amylase preparation. Formation of the active substance stimulates the isolated guinea pig ileum and produces a pressor response on dog and rabbit blood pressure. It differs from bradykinin since that substance is a vasodilator. The active substance produced by action of α-amylase on fraction IV-4 of plasma protein has been provisionally designated as Substance A. Further studies concerning enzymatic formation as well as purification and characterization of Substance A will be published.