cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of CAD Training in Microwave Education [Educator's Corner]

The nature of engineering practice has irreversibly changed within the past quarter of a century as a result of an increasingly greater reliance on computers and software. This has understandably been accompanied by a change in the way that educators in most engineering disciplines approach the task of preparing newcomers to their field, and RF and microwave engineering is no exception. Many courses in RF and microwave design— and, in particular, the design of RF integrated circuits—are now taught with a significant amount of instruction time devoted to the use of commercially available CAD software tools for carrying out circuit analysis, design, layout, simulation, and performance calculation.
Firm Heterogeneity and Wealth Distribution

In this paper I study how firm heterogeneity affects wealth distribution through entrepreneurial income and capital gains. As shown in Hottman, Redding and Weinstein 2016, size distribution of firms is highly skewed. Top 1% of firms on average have market shares of 50%. I develop a dynamic heterogeneous-agent general equilibrium model, where firms produce multiple products and households invest by bargaining with firm owners. Every product in this model has two dimensions: its rate of return and its optimal output. Every firm thus has two dimensions: its rate of return and size. Investors sort into different firms based on their wealth, which increases due to either their share of firm's profit or their capital gains. The distribution of product space is calibrated with Nielsen barcode dataset. The simulation shows that the firm heterogeneity in its two dimensions implied by the dataset results in a severe wealth inequality. The model can explain 90% of the rise in top wealth concentration between 2003 and 2012 in the United States and shows that the upswing in the top 1% wealth share is due to the rise in the top 0.1%, which is consistent with Saez and Zucman 2016. Counterfactual exercises highlight entrepreneurship as the main driver in wealth equality and show that fluctuations in risk free rate of return and access to new investment opportunities reduce wealth inequality, of which each may offset up to half of the effect of entrepreneurship.
Of form and function: Early cardiac morphogenesis across classical and emerging model systems

The heart is the earliest organ to develop during embryogenesis and is remarkable in its ability to function efficiently as it is being sculpted. Cardiac heart defects account for a high burden of childhood developmental disorders with many remaining poorly understood mechanistically. Decades of work across a multitude of model organisms has informed our understanding of early cardiac differentiation and morphogenesis and has simultaneously opened new and unanswered questions. Here we have synthesized current knowledge in the field and reviewed recent developments in the realm of imaging, bioengineering and genetic technology and ex vivo cardiac modeling that may be deployed to generate more holistic models of early cardiac morphogenesis, and by extension, new platforms to study congenital heart defects.
Multiple Testing in Economics

We propose a new way to conduct multiple hypothesis testing in economics research. Our framework allows for correlation among tests and incomplete data, both of which are prevalent in economic meta-analysis. Our simulations show that that our method is able to produce the correct p-value cutoff that controls the overall rate of false discoveries at a prespecified level of significance. The single hypothesis test, as used by most researchers, leads to too many false discoveries and should be avoided.
El control institucional de la corrupción: un marco analítico para su estudio

El diseno y la puesta en marcha de mecanismos de control institucional de la corrupcion resultan clave para incrementar la calidad democratica de los sistemas. De ahi que esta cuestion ocupe un lugar prioritario no solo en las agendas de numerosos gobiernos y organismos internacionales, sino tambien en la literatura especializada. Pese a la existencia de numerosos estudios encaminados a enfatizar la importancia de las instituciones a la hora de hacer frente al fenomeno de la corrupcion, la bibliografia centrada en el estudio empirico de tales mecanismos de control en un pais determinado y, sobre todo, la encaminada a analizar de que manera tales mecanismos contribuyen al accountability desde un punto de vista teorico, resulta ser mucho mas escasa. Teniendo en cuenta esto, el articulo tiene como objetivo contribuir al estudio empirico y cualitativo de los mecanismos de control de la corrupcion, aportando para ello un marco analitico construido a partir de unos criterios clasificatorios especificos basados en la Teoria de la Agencia. Tales criterios clasificatorios atienden, por un lado, a si el mecanismo concreto actua antes o despues de que la autoridad del Principal haya sido delegada al Agente (medidas ex ante y medidas ex post) y, por otro lado, a si el mecanismo actua con anterioridad o con posterioridad a que el acto corrupto se haya producido (medidas a priori y medidas a posteriori). A partir de ambos criterios se deducen consecuencias teoricas en terminos de accountability, de tal manera que el marco analitico que se propone permite no solo conocer cual es el enfoque que predomina en un pais concreto a la hora de controlar la corrupcion, sino ademas, conocer que implicaciones teoricas conlleva este enfoque en terminos de efectividad. No obstante, la novedad mas importante que aporta la aplicacion de dicho marco analitico a la realidad empirica es que permite realizar estudios comparados sobre como se ejerce el
Why Equal Protection No Longer Protects: The Evolving Forms of Status-Enforcing State Action

In this essay, Professor Siegel examines efforts to reform racial and gender status law in the nineteenth century in order to raise questions about the ways antidiscrimination law operates today. The essay demonstrates how efforts to dismantle an entrenched system of status regulation can produce changes in its constitutive rules and rhetoric, transforming the status regime without abolishing it. Part I illustrates this reform dynamic in the nineteenth century, a period when protest movements were demanding the abolition of slavery and reform of marital status law. Legislatures and courts responded by eliminating some of the more overtly hierarchical features of marital status law, yet adopted gender-biased policies governing domestic labor and domestic violence that were justified as promoting family privacy, rather than marital hierarchy. Similarly, in the aftermath of the Civil War, legislatures and courts granted the newly emancipated slaves "civil" rights, yet denied them "social" rights, rationalizing miscegation laws and segregation as preserving associational liberty, rather than racial hierarchy. As these examples illustrate, the rules and reasons the legal system employs to enforce status relationships evolve as they are contested. Part II of the essay uses this dynamic model of status regulation to analyze the operations of equal protection law today. We know that doctrines of heightened scrutiny have disestablished overtly classificatory forms of race and gender status regulation dating from the nineteenth century. Yet the doctrine of discriminatory purpose currently sanctions facially neutral state action that perpetuates race and gender stratification, so long as such regulation is not justified in discredited forms of status-based reasoning. Once we recognize that the rules and reasons the legal system employs to enforce status relations evolve as they are contested, we ought to scrutinize justifications for facially neutral state action with skepticism, knowing that we may be rationalizing practices that perpetuate historic forms of stratification, much as Plessy v. Ferguson once did.
The Prehistory of Port au Choix: History, Cultures, and Landscapes

THIS SYNTHESIS of three decades of research on the archaeology of Port au Choix on the western coast of Newfoundland establishes it as one of the most important archaeological locations in Canada. Port au Choix has been known for its archaeology since the days of Howley, Kidder, and Jenness. Its regional importance was confirmed by Wintemberg and Harp, and major excavations at the Phillip’s Garden Dorset site by Harp and at Maritime Archaic cemeteries by Tuck revealed its long history and cultural complexity. Harp was the first to document the site’s Dorset material culture, age, cultural affiliation, and settlement aspects. In 1984, after Tuck revealed an equally impressive Maritime Archaic occupation, Parks Canada designated the Port au Choix region as a National Historic Site, built a museum, and initiated more than two decades of Memorial University research directed by
Twin Test: On Discriminability of Fingerprints

Automatic identification methods based on physical biometric characteristics such as fingerprint or iris can provide positive identification with a very high accuracy. However, the biometrics-based methods assume that the physical characteristics of an individual (as captured by a sensor) used for identification are distinctive. Identical twins have the closest genetics-based relationship and, therefore, the maximum similarity between fingerprints is expected to be found among identical twins. We show that a state-of-the-art automatic fingerprint identification system can successfully distinguish identical twins though with a slightly lower accuracy than nontwins.
The Preeminence of Early Life Trauma as a Risk Factor for Worsened Long-Term Health Outcomes in Women

Early life trauma (ELT) comprises an array of disturbingly common distressing experiences between conception and the beginning of adulthood with numerous and significant potential long-term, even transgenerational, health consequences of great public health concern, including depression, cardiovascular disease, and other psychiatric and medical disorders, and neurobiological, psychological, and behavioral effects which are sufficiently robust to confound many types of biomedical research. The impact of ELT on a woman's health trajectory appears to vary with the specific characteristics of the ELT (e.g., type, number of different types, severity, and timing), the individual (e.g., age, genetics, epigenetics, personality, and cognitive factors), and the individual's environment (e.g., level of social support and ongoing stressors) and to be mediated to a significant extent by persistent changes in a number of biological systems, dysregulation of those governing the stress response chief among them. Growing knowledge of the risk factors and pathophysiological mechanisms by which ELT confers diathesis to various poor health outcomes and the unique treatment-response profiles of women with ELT will lead to much needed improvements in prevention, diagnostic, and therapeutic efforts, including more effective psychotherapy and pharmacotherapy approaches, hopefully making strides toward improvements in the lives of women everywhere and ending countless cycles of intergenerational trauma-associated pathology. This article attempts to broadly summarize the current state of knowledge about the long-term sequelae of ELT for women's health.
Multiple imputation of missing values: Update of ice

Royston (2004) introduced mvis, an implementation for Stata of MICE, a method of multiple multivariate imputation of missing values under missing-at-random (MAR) assumptions. In a second article, Royston (2005) described ice, an upgrade incorporating various improvements and changes to the software based on personal experience, discussion with colleagues, and user requests. This article describes an update to ice. The changes are less substantial but nevertheless important enough to warrant a brief explanation. The major modification is that the default method of imputing missing values in ice is now by sampling from the posterior predictive distribution rather than by predicted mean matching. The ice system comprises five ado-files: ice, micombine, mijoin, misplit, and uvis. The last three programs have not been changed and are included in the present release for the sake of completeness.
Acute kidney injury: AKI in acute myocardial infarction--are we making progress?

A recent report suggests that the incidence of acute kidney injury (AKI) in patients with acute myocardial infarction declined between 2000 and 2008 and was associated with decreased mortality despite concurrent increases in comorbidities. Although encouraging, changing patterns of care and an understanding of factors contributing to AKI in this setting must be considered.
Reaction of the copper dimer, Cu2 with ethylene in the gas phase☆

Abstract The gas-phase kinetics of the reaction between Cu 2 and C 2 H 4 have been studied as a function of pressure in a fast-flow reactor. The limiting low-pressure, third-order rate constant for the reaction was found to be (9.3±1.4) × 10 −30 cm 6 s −1 in He. Modeling studies of this rate constant imply that Cu 2 (C 2 H 4 ) is bound by at least 20 kcal mol −1 .
Advanced ab initio and hybrid density functional theory evaluation of the atomization energies, bond dissociation pathways, and heats of formation of the two isomers of HClO4

Abstract The reliability of various ab initio and density functional theory models has been evaluated in the past for the study of bond dissociation energies, heats of formation, etc [1] , [2] , [3] . We present two novel results, the first being evidence for the formation of HO4Cl, the first isomer, as well as the effect of basis set choice for a molecular orbital calculation of these types of systems. For all the density functional theory methods we have employed the B3LYP method with the 6-311++G (d, p), 6-311++G (2d, 2p), 6-311++G (3d, 3p), and 6-311++G (3df, 3pd) basis sets and have found that the predicted energies yield a higher energy for the second isomer of HClO4, HOClO3, but when a very large basis set was used (6-311++G (3df, 3pd)) the latter was found to be lower in energy than the former, which is in correlation with previously published results [1] . The same unusual effect were seen in the Hartree–Fock (HF), MP2, and MP4 methods where the 6-31G(d), 6-31G(d′), and 6-311G(d, p) were unable to correlate (to a reasonable extent for MP2 and MP4 methods) with the experimental value of around 4 kcal/mol for the heat of formation of HOClO3 unless the CBSB3 or CBSB4 basis sets were implemented. We have also investigated five possible dissociation channels for radical mechanisms as well as the atomization energies of the two isomers at various theory methods, with various basis sets.
Oxidative cyclization of β,γ-unsaturated O-acyl hydroxamates to β-lactams

Abstract Reaction of O-Acyl vinylacetohydroxamates with bromine and base in aqueous acetonitrile provides a direct route to substituted 4-(bromomethyl)-N-hydroxy β-lactams.
Model verification in lambda sigma : a type inference approach

The author describes a number of model analysis and verification operations based on type inference in the lambda sigma simulation language. lambda sigma is a simulation language based on the typed lambda -calculus. lambda sigma entities correspond to typed lambda -expressions, while lambda sigma activities correspond to subtypes. Thus, entities can be generated by means of type-introduction rules, and operations can be defined on entities by means of type elimination and equality rules. Premises of the form e in tau in an introduction rule used to create a new entity can be satisfied by substituting for e any entity of type tau in a neighboring activity. It is then possible to perform a number of model analysis and verification operations using type inference algorithms available for the typed lambda -calculus. >
Letter from Vancouver: Practice-Based Arts Education Policies October 2006.

ABSTRACT A leading arts educator speaks on practice-based arts education policy in Canada and beyond.
Exercise-induced st segment depression in the diagnosis of multivessel coronary disease: A meta analysis

To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).
Egg crypsis and clutch survival in three species of blackbirds (Icteridae)

For most open-nesting passerine birds, the primary function of egg pigmentation is crypsis. Interspecific variation for egg coloration is quite high, even among species that nest in the same locale. This variation might be maintained by selection to blend into species-specific nest cups, which vary in pattern because they are constructed from different materials. To test this hypothesis we photographed 30 clutches of Brewer's blackbirds (Euphagus cyanocephalus), 26 clutches of red-winged blackbirds (Agelaius phoeniceus), and 24 clutches of yellow-headed blackbirds (Xanthocephalus xanthocephalus), and quantified crypsis in terms of pattern (PD crypsis), brightness (MB crypsis) and brightness disparity (BD crypsis). The species were equally cryptic in terms of pattern crypsis, but differed significantly (P < 0·01) in MB and BD crypsis. Intraspecific variation in pattern crypsis was surprisingly high. Mean clutch pattern disparity was highly correlated with mean background pattern disparity (r = 0·999); this suggests selection for disparity matching, rather than for crypsis. We also monitored 25 clutches (7 Brewer's, 9 red-winged, and 9 yellow-headed blackbirds) for a 9-day period to determine if survival was related to crypsis. For Brewer's and yellow-headed blackbirds, successful nests were no more cryptic than failed nests. For red-winged blackbirds, there was a tendency (P = 0·1) for less cryptic clutches to have higher survival; in addition, successful red-winged blackbird clutches had significantly (P < 0·05) higher egg pattern disparity and background pattern disparity. Red-winged blackbird clutches are not concealed by overhanging vegetation, and high pattern disparity may enable them to blend into a large-scale heterogeneous background.
Diffraction tomographic reconstruction from intensity data

The problem of reconstructing the complex index of refraction of a weakly inhomogeneous scattering object from measurements of the magnitude (intensity) of the transmitted wavefields in a set of scattering experiments within the context of diffraction tomography (DT) is addressed. It is shown that high quality approximate reconstructions can be obtained from such intensity data using standard reconstruction procedures of DT. The physical basis for the success of these procedures when applied to intensity data is discussed and computer simulations are presented comparing the approximate reconstructions generated from intensity data with the optimum reconstructions generated from both the magnitude and phase of the transmitted wavefields. >
Problems of quality and equity in pain management: exploring the role of biomedical culture.

Objectives. To explore how social scientific analyses of the culture of biomedicine may contribute to advancing our understanding of ongoing issues of quality and equity in pain management. Design. Drawing upon the rich body of social scientific literature on the culture of biomedicine, we identify key features of biomedical culture with particular salience for pain management. We then examine how these cultural features of biomedicine may shape key phases of the pain management process in ways that have implications not just for quality, but for equity in pain management as well. Setting and Patients. We bring together a range of literatures in developing our analysis, including literatures on the culture of biomedicine, pain management and health care disparities. Measures. We surveyed the relevant literatures to identify and inter-relate key features of biomedical culture, key phases of the pain management process, and key dimensions of identified problems with suboptimal and inequitable treatment of pain. Results. We identified three key features of biomedical culture with critical implications for pain management: 1) mind-body dualism; 2) a focus on disease vs illness; and 3) a bias toward cure vs care. Each of these cultural features play a role in the key phases of pain management, specifically pain-related communication, assessment and treatment decision-making, in ways that may hinder successful treatment of pain in general—and of pain patients from disadvantaged groups in particular. Conclusions. Deepening our understanding of the role of biomedical culture in pain management has implications for education, policy and research as part of ongoing efforts to ameliorate problems in both quality and equity in managing pain. In particular, we suggest that building upon the existing the cultural competence movement in medicine to include fostering a deeper understanding of biomedical culture and its impact on physicians may be useful. From a policy perspective, we identify pain management as an area where the need for a shift to a more biopsychosocial model of health care is particularly pressing, and suggest prioritization of inter-disciplinary, multimodal approaches to pain as one key strategy in realizing this shift. Finally, in terms of research, we identify the need for empirical research to assess aspects of biomedical culture that may influence physician's attitudes and behaviors related to pain management, as well as to explore how these cultural values and their effects may vary across different settings within the practice of medicine.
An investigation of bulk stacking faults in silicon using photocapacitance transient spectroscopy

Abstract Two-step heat-treated silicon wafers have been used to determine the electrical activity of bulk stacking faults. DLTS measurements by Forbes and Haddad show a dominant energy level at Ec − Et = 0.48 ±0.05 eV due to oxygen-induced stacking faults. These wafers have been processed in two different facilities to minimize the possibility that the results might depend on impurities incorporated during wafer processing. Low-temperature, photocapacitance transient spectroscopy (PCTS) was used to study the optical cross section as a function of incident photon energies, in the 1300 to 3000 nm range. PCTS measurements done on the same samples show a dominant level at Ec−Et = 0.48 ± 0.05 eV. These results are in excellent correlation with the DLTS measurements.
Probing Cu(II)/H2O2 damage in DNA with a damage-specific DNA binding protein

Abstract A human damage-specific DNA binding protein has been employed as a sensitive probe of damage introduction by the combination of Cu(II) and H 2 O 2 . Optimal conditions for the introduction of protein-recognizable lesions into DNA in the Cu(II)/H 2 O 2 system were obtained with 10[ −5 -M CuCl 2 and 0.10-mM H 2 O 2 . The absolute requirement for the presence of a metal ion suggests the involvement of a metal catalyzed Fenton reaction. However, damage introduction in the presence of KI and dimethylsulfoxide indicate that hydroxyl radical, while responsible for the introduction of strand breaks, is not the primary species responsible for lesion introduction. Protein-recognizable damage was introduced into DNA and poly d(G-C), but not into poly d(A-T). Loss of label from the five position of cytosine was also observed at high peroxide levels.
Xenopus axin interacts with glycogen synthase kinase-3 beta and is expressed in the anterior midbrain

Abstract Axin is encoded by the fused locus in mice and is required for normal vertebrate axis formation. It has recently been shown that axin associates with the adenomatous polyposis coli gene product (APC), β -catenin and glycogen synthase kinase-3 (GSK-3) in a complex that appears to regulate the level of cytoplasmic β -catenin. We have identified the Xenopus homologue of axin through its interaction with GSK-3 β . Xenopus axin (Xaxin) is expressed maternally and throughout early development with a low level of ubiquitous expression. Xaxin also shows remarkably high expression in the anterior mesencephalon adjacent to the forebrain–midbrain boundary.
Occurrence of Acetylcholine-Hydrolyzing Activity at the Stele-Cortex Interface

Acetylcholine (ACh) is a chemical transmitter serving to propagate an electrical perturbation across the synaptic junctions of animals. ACh and AChE have previously been demonstrated to occur in plants. In this work, we detected AChE at the interface between stele and cortex of the mesocotyl of Zea mays by measuring hydrolysis of acetylthiocholine and by liberation of labeled acetate from [1-14C]ACh. AChE activity was also detected in a crude membrane fraction. The hydrolytic activity is inhibited by neostigmine. Hydrolysis of ACh was also measured after injection of [1-14C]ACh into kernels of Zea mays and the radioactivity transported into the mesocotyl cortex. A gravity stimulus was then given by placing the plants in a horizontal position. Significantly more radioactivity was found in the lower cortex of horizontally placed seedlings. A working hypothesis is presented for the involvement of ACh and AChE in the tropic response of Z. mays seedlings.
Six Sigma Applied Throughout the Lifecycle of an Automated Decision System

Automated decision-making systems have been deployed in many industrial, commercial, and financial applications. The needs for such systems are usually motivated by requirements for variation reduction, capacity increase, cost and cycle time reduction, and end-to-end traceability of the transaction or product. Before we can use any automated decision-making system in a production environment we must develop a strategy to insure high quality throughout its entire lifecycle. We need to guarantee its performance through a rigorous Design for Six Sigma process (DFSS). This process includes validation, tuning, and production testing of the system. Once the system is in production we must monitor and maintain its performance over its lifecycle. In this paper we will outline the Six Sigma process that led to the deployment of an automated decision-making system in one of the General Electric Financial Assurance businesses. Copyright © 2005 John Wiley & Sons, Ltd.
Seeing stars: a molecular and morphological investigation into the evolutionary history of Odontasteridae (Asteroidea) with description of a new species from the Galapagos Islands

Odontasteridae (Asteroidea: Echinodermata) (Verrill in Am J Sci, 1899) is placed within Valvatida, a derived assemblage of sea stars. Odontasterids are found in the Southern, Atlantic, and Pacific Oceans and are concentrated in high southern latitudes. To date, the phylogenetic and evolutionary history of Odontasteridae as a whole has not been rigorously examined. We conducted molecular and morphological phylogenetic analyses of Odontasteridae to assess the interrelationships among and within recognized genera. We used mitochondrial 16S and cytochrome c oxidase subunit I molecular markers and 29 external morphological characters in an attempt to reconstruct the evolutionary history of the group. Generally, our results indicate that traditionally used external skeletal characters are not representative of phylogenetic history of Odontasteridae. We can conclude that species present in high latitudes in the Southern Hemisphere (i.e., Southern Ocean) are the most derived taxa. Additionally, mtDNA data suggest unrecognized lineages of odontasterids are present in high southern latitudes. A new species Odontaster cynthiae sp. nov. is described from the Galapagos Islands.
Superior colliculus responses to light - Preserved by transplantation in a slow degeneration rat model

Author(s): Thomas, Biju B; Seiler, Magdalene J; Sadda, SriniVas R; Aramant, Robert B | Abstract: PurposeTo determine whether retinal transplantation can preserve visual responses in the superior colliculus (SC) of the S334ter-line-5 rat, a transgenic model for slow photoreceptor degeneration, which is more similar to human retinitis pigmentosa than the fast degeneration line 3 S334ter rat.MethodsVisual responses to a light flash were recorded in the SC. Rats that had received embryonic day (E) 19-20 fetal retinal sheet transplants at the age of 26-30 days were tested at the ages of 200-254 days. Controls were age-matched rats without surgery and with sham surgery. As a baseline, in no-surgery line-5 rats, the temporal pattern of visual sensitivity loss was evaluated electrophysiologically in the SC from 60 days up to one year of age.ResultsIn untreated S334ter-line-5 rats, decline in visual sensitivity in the SC was parallel to the photoreceptor loss. At 109 day of age, a relative scotoma developed in the area of the SC corresponding to the nasal retinal region. At 200-254 days of age, the majority of the SC was devoid of any light-driven responses. In contrast, at this time point, transplanted rats with 'good' retinal grafts with normal lamination had visual responses in the caudal region of the SC, the area corresponding topographically to the transplant location in the retina. In these rats, the various parameters of SC responses such as the latency of the onset of the visual response, the response peak amplitude and the consistency of the visual response were significantly different from the control groups (no-surgery, sham surgery, 'poor' transplants) and were more comparable to normal albino rats, however, with a slightly longer latency (70-90 vs. 30-50 msec).ConclusionsFetal retinal sheet transplantation showed a long-term rescue effect on visual function in this animal model of slow photoreceptor degeneration.
Classroom observation data and instruction in primary mathematics education: improving design and rigour

The use of formal observation in primary mathematics classrooms is supported in the literature as a viable method of determining effective teaching strategies and appropriate tasks for inclusion in the early years of mathematics learning. The twofold aim of this study was to (a) investigate predictive relationships between primary mathematics classroom observational data and student achievement data, and (b) to examine the impact of providing periodic classroom observational data feedback to teachers using a Relational-Feedback-Intervention (RFI) Database Model. This observational research effort focused on an empirical examination of student engagement levels in time spent on specific learning activities observed in primary mathematics classrooms as predictors of student competency outcomes in mathematics. Data were collected from more than 2,000 primary classroom observations in 17 primary schools during 2009–2011 and from standardised end-of-year tests for mathematics achievement. Results revealed predictive relationships among several types of teaching and learning tasks with student achievement. Specifically, the use of mathematics concepts, technology and hands-on materials in primary mathematics classrooms was found to produce substantive predictors of increased student mathematics achievement. Additional findings supported the use of periodic classroom observation data reporting as a positive influence on teachers’ decisions in determining instructional tasks for inclusion in primary mathematics classrooms. Study results indicate classroom observational research involving a RFI Database Model is a productive tool for improving teaching and learning in primary mathematics classrooms.
Intersubband selection and sum rules in a patterned inverse quantum dot array

We present an analysis of the physics of intersubband transitions in a patterned inverse quantum dot (IQD) array. Numerical techniques for computing the oscillator strength for intersubband transitions are outlined along with the selection and sum rules. It is demonstrated that the polarization dependence of intersubband absorption can be controlled through appropriate design of the IQD array geometry.
EMS providers' perceptions of safety climate and adherence to safe work practices

AbstractBackground. Occupational injuries are an important source of morbidity for emergency medical services (EMS) providers. Previous work has shown that employee perceptions of an organization's commitment to safety (i.e., safety climate) correlate with adherence to safe practices. Objective. To assess the association between perceived safety climate and compliance with safety procedures in an urban EMS system with >100,000 calls/year. Methods. EMS providers were issued a self-administered survey that included questions on demographics, years of experience, perceived safety climate, and adherence to safety procedures. Safety climate was assessed with a 20-item validated instrument. Adherence to safety procedures was assessed with a nine-item list of safety behaviors. Strict adherence to safety procedures was defined as endorsing “agree” or “strongly agree” on 80% of items. The effect of safety climate on compliance with safe practices was estimated using multiple logistic regression. Results. One hundr...
Mechanical ventilation and cerebral palsy.

The article by Laptook et al1 in the March 2005 issue of Pediatrics offered an interesting analysis of varying risk factors related to the development of cerebral palsy (CP) and neurodevelopmental delay (NDD) in extremely low birth weight (ELBW) infants. Despite having normal head ultrasound results, the incidence of CP and NDD in ELBW infants was almost 30%. Factors associated with CP/NDD were male gender, multiple births, decreasing birth weight, and increasing duration of conventional mechanical ventilation (MV). The relation of MV duration and CP retained its significance after controlling for other possible confounders in a multiple-regression model. For example, in a group of ELBW infants with the same gestational age, birth weight, gender, race, prenatal history, socioeconomic status, insurance type, use of surfactant and postnatal steroids, and incidence of pneumothorax, necrotizing enterocolitis, and late-onset sepsis, an infant would have a 20% higher chance of developing CP/NDD if he or she were maintained an additional 10 days on MV. The impact … Reprint requests to (H.A.) Department of Neonatology, George Washington University Hospital, 900 23rd St NW, Suite G-2092, Washington, DC 20037. E-mail: haly{at}mfa.gwu.edu
Mean Field Calculations of Bose-Einstein Condensation of 7Li Atoms In a Harmonic Trap

A self-consistent mean-field theory for bosons for T>0 is used to reconcile predictions of collapse with recent observations of Bose-Einstein condensation of 7Li. Eigenfunctions of a (non-separable) Hamiltonian that includes the anisotropic external trap field and atom-atom interactions are obtained by an iteration process. A sum over the Bose distribution, and the ``alternating direction implicit'' algorithm are used. Near Tc, the ensemble exhibits a localized condensate composed of atoms in the few lowest states. For lower T, numerical instability indicates collapse to a more dense phase.
Information theory and privacy in data banks

The problem of providing privacy and security in retrieval systems falls into two rather modern disciplines: information theory and computer science. In this paper the concern is primarily with the former, i.e., how to relate security of data records in computerized retrieval systems and data banks with Shannon's information-theoretic treatment of secrecy systems for natural language messages in communication systems. In doing so, it is useful to establish first the analogy between retrieval systems and certain communication channels.
Analysis by two-dimensional polyacrylamide gel electrophoresis of liver ribosomal subunit proteins obtained from free and membrane-bound polysomes of unfasted animals

Abstract Ribosomal proteins were analyzed by means of two-dimensional gel electrophoresis. To insure that the analysis included only that fraction of the ribosome actively participating in protein synthesis, only polysomal-bound ribosomes were used. This differs from previously reported analyses of liver ribosomal proteins. The ribosomal proteins were prepared from ribosomes of polysomal origin from membrane-bound and free polysomes. Membrane-bound and free liver polysomes were isolated from unfasted mice. The polysomes were purified on hydroxyapatite under conditions known to result in polysomes and ribosomes that are active in both endogenous and synthetic mRNA translation. Moreover, this is the first time that liver ribosomal protein was obtained and analyzed from animals that have not been starved prior to sacrifice. The puromycin-released ribosomes were dissociated into subunits and ribosomal proteins were analyzed by means of two-dimensional polyacrylamide gel electrophoresis. When 100–200 μg samples of the ribosomal subunit proteins were analyzed by two-dimensional electrophoresis, approximately 32 major proteins were detected for the 60 S ribosomal subunit and 25 major proteins for the 40 S ribosomal subunit. A total of 13 “fractional” ribosomal proteins was also detected in the ribosomal subunit profiles. No differences in number or mobility of the ribosomal proteins were found between the membrane-bound and free ribosome populations. We describe a system in which all ribosomal proteins are completely solubilized and quantitatively move from the first to the second dimension gel. Thus the total sample is separated and fractionated. This procedure eliminates artifacts due to incomplete solubilization of ribosomal proteins, which is common for the transfer from the first- to second-dimension gel. Therefore, a more detailed and accurate analysis is achieved.
Drug insight: If inhibitors as specific heart-rate-reducing agents.

Despite treatment being available for angina in the form of β-blockers and calcium-channel blockers, these drugs are contraindicated in some patients. PharmacologicalIfinhibition could prove a promising alternative for protection from angina through heart-rate slowing. This review discusses the early mechanisms and early clinical use of ivabradine as a specific bradycardic agent. Heart rate is determined primarily by spontaneously repeating net inward current carried by sodium ions and potassium ions through hyperpolarization-activated cyclic-nucleotide-gated channels. Within the heart, these channels are found most abundantly in sinoatrial cardiomyocytes. The channels open in response to membrane hyperpolarization, modulated by local cAMP concentrations. They permit activation of the If current, which can be blocked specifically by molecules characterized by linked benzazepinone and benzocyclobutane rings, and which are devoid of effects on cardiac conduction, inotropy or peripheral vascular tone. The resulting heart-rate reduction has been effective in angina prevention in clinical trials involving 4,000 patients, using the prototype If inhibitor, ivabradine. No serious adverse events have been attributed to the treatment; the most prominent side-effect is dose-related, always reversible and often transient visual symptoms that seldom result in voluntary drug discontinuation.
An analysis of food and drug administration medical device reports relating to total joint components

A total of 1,717 total hip and 2,769 total knee medical device reports submitted to the U.S. Food and Drug Administration (FDA) from 1984 through 1993 were reviewed. A large percentage of total hip complications could be attributed to some aspect of component modularity. Cementless modular acetabular components were the single largest source of device-related complications. Fifty-six percent of total knee medical device reports (MDRs) were associated with accelerated polyethylene wear. By location, MDRs identified patellar (46%), tibial (33%), and femoral (5%) component complications. It was estimated that less than 5% of device-related complications were reported to the FDA. Based on the reports received, it was apparent that mechanical failure of components was a common and increasing cause of total joint revision.
Reduced diazepam binding following chronic benzodiazepine treatment.

Abstract Specific 3 H-diazepam binding was measured in rat cortex after 7–10 days of twice daily injection of a large dose of flurazepam. Compared to cortex taken from saline treated controls, there was a statistically significant decrease of about 15% in the maximum binding capacity (B max ). There was also a change in the dissociation constant (K D ) from 5.27 to 8.80 nM. Repeated washing of the tissue sample before the binding assay showed that the B max was truly decreased in the treated animals, but the change in K D was probably an artifact due to residual flurazepam remaining in the tissue that interfered with the binding assay. It is concluded that chronic benzodiazepine treatment caused an apparent decrease in the number of specific binding sites.
Acute phase responses vary with pathogen identity in house sparrows (Passer domesticus)

Pathogens may induce different immune responses in hosts contingent on pathogen characteristics, host characteristics, or interactions between the two. We investigated whether the broadly effective acute-phase response (APR), a whole body immune response that occurs in response to constitutive immune receptor activation and includes fever, secretion of immune peptides, and sickness behaviors such as anorexia and lethargy, varies with pathogen identity in the house sparrow (Passer domesticus). Birds were challenged with a subcutaneous injection of either a glucan at 0.7 mg/kg (to simulate fungal infection), a synthetic double-stranded RNA at 25 mg/kg (to simulate viral infection), or LPS at 1 mg/kg (to simulate a gram-negative bacterial infection), and then body mass, core body temperature changes, sickness behaviors, and secretion of an acute-phase protein, haptoglobin, were compared. Despite using what are moderate-to-high pyrogen doses for other vertebrates, only house sparrows challenged with LPS showed measurable APRs. Febrile, behavioral, and physiological responses to fungal and viral mimetics had minimal effects.
Exclusion As Self-Protection The Function of Subtypes for Ingroup Members

Three studies examined the consequences of subtyping ingroup members for evaluations of the self. The first study examined the impact of subtyping high-performing or low-performing ingroup members on self-evaluations. Study 2 employed an alternative manipulation of subtyping. Given the observed benefits of subtyping low-performing ingroup members for the group and the benefits of subtyping high-performing ingroup members for the self, Study 3 investigated participants’ subtyping target selection (i.e., high-performing vs. low-performing ingroup members) when the focus of the sorting task was on self-evaluations or group evaluations. In sum, these studies suggest that subtyping ingroup members can serve a self-protective function.
U.S. Foreign Aid and U.N. Voting: Did Reagan's Linkage Strategy Buy Deference or Defiance?

The Reagan administration's 1986 policy initiative linking the allocation of U.S. foreign aid to recipient voting behavior in the U.N. General Assembly is evaluated. Aid levels and voting patterns are examined prior to and after the implementation of the declared bargaining policy. To maximize validity, the data are subjected to a variety of statistical treatments, including construction of a cross-lagged path model. None of the results emerging from these treatments produced statistical evidence that a relationship was present. The data demonstrate that the strategy did not produce the effects envisioned by its framers: The policy fell short of its goal of eliciting compliance behavior through threats of economic sanctions. Contending reasons for the strategy's failure are advanced in a concluding interpretation.
Suppression of Adventitious Formation of 8-Oxoguanine(TMS)4from Guanine during Trimethylsilylation

GC/MS quantitation of 8-oxoguanine derived from DNA may yield artificially high values when trimethylsilylation is used as the technique to form a volatile derivative. Significant quantities of thetetrakistrimethylsilyl-derivative of 8-oxoguanine may be formed from guanine during the derivatization reaction at elevated temperatures. We have screened eight antioxidants in an attempt to identify a substance that will reduce the spurious formation of this product. Whereas several compounds were active,N-phenyl-1-naphthylamine was the most effective agent. Moreover, this compound was sufficiently basic to act as a catalyst for the derivatization reaction. Our data, which are based on the use of an isotopically labeled internal standard, show that the level of thetetrakistrimethylsilyl derivative of 8-oxoguanine remained constant as a function of derivatization heating time whenN-phenyl-1-naphthylamine was added to a reaction in which guanine was present. In contrast, the level in control samples increased linearly with reaction time indicating formation of 8-oxoGua during derivatization. The level of 8-oxoguanine was measured in both a synthetic oligodeoxynucleotide containing a single 8-oxo-2′-deoxyguanosine moiety and commercially available calf thymus DNA using this technique.
Evaluating remote sensing image fusion algorithms for use in humanitarian crisis management

This study investigated how different fusion algorithms performed when applied to very high spatial resolution (VHSR) satellite images that encompass ongoing- and post-crisis scenes. The evaluation entailed twelve fusion algorithms. The selected algorithms were applied to GeoEye-1 satellite images taken over three different geographical settings representing natural and anthropogenic crises that had occurred in the recent past: earthquake-damaged sites in Haiti, flood-impacted sites in Pakistan, and armed-conflicted areas and internally displaced persons (IDP) camps in Sri Lanka. Spectral quality metrics included correlation coefficient, peak signal-to-noise ratio index, mean structural similarity index, spectral angle mapper, and relative dimensionless global error in synthesis. The spatial integrity of fused images was assessed using Canny edge correspondence and high-pass correlation coefficient. Under each metric, fusion methods were ranked and best competitors were identified. In this study, the Ehlers fusion, wavelet-PCA fusion (WVPCA), and the high-pass filter fusion algorithms reported the best values for the majority of spectral quality indices. Under spatial metrics, the University of New Brunswick and Gram-Schmidt fusion algorithms reported the optimum values. The color normalization sharpening and subtractive resolution merge algorithms exhibited the highest spectral distortions where as the WV-PCA algorithm showed the weakest spatial improvement. In conclusion, we recommend the University of New Brunswick algorithm if visual image interpretation is involved, whereas the high-pass filter fusion is recommended if semi- or fully-automated feature extraction is involved, for pansharpening VHSR satellite images of ongoing and post crisis sites