cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigation of three-step epilayer growth approach of GaN thin films to minimize compensation

In this paper, semiconductor nitride deposition are performed on sapphire substrates that have significant lattice mismatch such that strain accommodating nucleation layers are required to obtain reasonable crystallinity. The ultimate microstructure and electrical quality are of the subsequent film then becomes reliant on two things: the properities of the nucleation layer and heteroepitaxial nucleation on this nucleation layer. This is because the extended defects resulting in the film influence the level of compensation in the film. Thin film growth by MOCVD 1) AlN nucleation layer growth, 2) GaN nucleation and coalescence, and 3) GaN homoepitaxial growth on the fully coalesced film from step 2.GaN layer as determined by in-situ laser interferometry and confirmed by ex-situ AFM measurements. Select films are further characterised by cross-section TEM in an effort to correlate electrical property measurements with film defect and microstructure.
Extension-sensitivity in the crayfish abdomen

1. In the isolated crayfish abdominal cord, the “spontaneous” discharge of postural motor neurons was found to depend (tonically) on cord length. This tonic cord stretch reflex inhibits flexor and excites extensor motor neurons and recruits additional extensor neurons. 2. The necessary and sufficient stimulus for the reflex in a particular ganglion is stretch of any part of the more posterior cord segments; stretch applied to anterior segments is without influence. 3. The reflex is present over the range of cord lengths obtaining in the intact animal. 4. The discharge rate of the tonic stretch receptor is shown to be also influenced. Evidence is presented that this is by way of the motor neuron which shares innervation of the superficial extensor musculature and the muscular part of the stretch receptor organ. 5. The existence of the tonic cord stretch reflex is taken as added evidence of the proprioceptive role of the cord stretch receptor system. The potential positive feedback nature of the reflex, its relation to other known proprioceptive reflexes, and its possible functional role are discussed.
Frequency and significance of a small distal ICA in carotid artery stenosis.

PURPOSE Accurate calculation of the percentage of stenosis is crucial for identifying candidates for endarterectomy. Our goal was to quantify the reduction in diameter of the distal internal carotid artery (ICA) as a function of proximal ICA stenosis and to discuss the implications of distal ICA narrowing on the calculation of percentage of stenosis using the criteria of the North American Symptomatic Carotid Endarterectomy Trial (NASCET). METHODS We retrospectively reviewed the carotid angiograms of 81 patients referred for evaluation of carotid stenosis. The caliber of the ICA stenosis and the diameters of the normal distal ICA, the common carotid artery, and the internal maxillary artery were remeasured with precision calipers. The percentage of stenosis derived from the NASCET criteria were compared with vessel diameter and with the difference in size of the ipsilateral and contralateral distal ICAs. We then recalculated the percentage of stenosis by substituting the presumed normal contralateral distal ICA diameter for the ipsilateral distal ICA diameter. RESULTS In carotid arteries without significant stenosis ( 70%), the distal ICA diameter measured 4.69+/-1.23 mm. After recalculation, four of 26 vessels were upgraded in classification from moderate (40% to 69%) to severe (>70%) stenosis. CONCLUSION The diameter of the distal ICA begins to decrease when the proximal stenosis is 60% or greater. If the ICA distal to a stenosis is smaller than the contralateral ICA, recalculating the percentage of stenosis by substituting measurements of the contralateral distal ICA diameter may be warranted.
Teaching Bird Identification & Vocabulary with Twitter

Species identification is essential to biology, conservation, and management. The ability to focus on specific diagnostic characteristics of a species helps improve the speed and accuracy of identification. Birds are excellent subjects for teaching species identification because, in combination with their different shapes and sizes, their plumages have distinctive colors and patterns that vary characteristically from species to species. Bird feather tracts have specific names so that proper descriptions of colors and patterns on those tracts can improve the precision and conciseness of identification criteria. We use popular social media (Twitter) to engage students in an exercise designed to familiarize them with avian species identification and improve their use and comprehension of vocabulary. This exercise can be used in higher education for ornithology and other identification courses, as well as in primary education as a basic introduction to species and biodiversity.
Visualization for increased understanding and learning using augmented reality

Augmented reality allows the superimposing of computer-generated images over real scenes in real time. This paper describes a project in which an interactive solar system was developed to help middle school students in the sciences understand spatial concepts using augmented reality. The marker-based augmented reality application works by using a camera to read a marker, then calculates the camera position in 3D space, and superimposes the solar system. With a webcam and a laptop, augmented reality application development is highly accessible.The visualization application research detailed here will be used for formal pedagogical research examining whether students benefit from this method by conducting both pre-event and post-event assessment surveys. The surveys will gather valuable feedback from middle-school science students concerning whether the augmented reality method is effective for teaching and learning. Preliminary feedback from students and educators indicates that this visual teaching method is effective.
Actin cleavage in various tumor cells is not a critical requirement for executing apoptosis

Actin is a major cytoskeletal protein which is involved in many physiological cellular functions such as motility, cell shape, and adhesion. Recently, actin has also been reported to be cleaved by apoptotic proteases (i.e., caspases) and this cleavage is thought to contribute to the apoptotic process. However, conflicting data also exists as to whether actin represents a true caspase substrate during apoptosis induction in vivo (i.e., inside the cells). In this study, we critically examined the actin cleavage patterns during apoptosis of several tumor cell lines derived from three different species (i.e., mouse, rat, and human). Our findings demonstrate that: 1) actin cleavage in vivo is not a common phenomenon since apoptosis caused by multiple inducers in most cell types examined occurs without evidence of actin degradation; and 2) in certain cell types (e.g., U937), spontaneous, actin cleavage is observed which is not prevented by various specific chemical/peptide inhibitors of proteases such as caspases or serine proteases although apoptosis per se is retarded by some of these inhibitors. Our results conclude that actin is not a critical substrate for apoptotic proteases in vivo during apoptosis.
Circadian transcription contributes to core period determination in Drosophila.

The Clock–Cycle (CLK–CYC) heterodimer constitutes a key circadian transcription complex in Drosophila. CYC has a DNA-binding domain but lacks an activation domain. Previous experiments also indicate that most of the transcriptional activity of CLK–CYC derives from the glutamine-rich region of its partner CLK. To address the role of transcription in core circadian timekeeping, we have analyzed the effects of a CYC–viral protein 16 (VP16) fusion protein in the Drosophila system. The addition of this potent and well-studied viral transcriptional activator (VP16) to CYC imparts to the CLK–CYC-VP16 complex strongly enhanced transcriptional activity relative to that of CLK–CYC. This increase is manifested in flies expressing CYC-VP16 as well as in S2 cells. These flies also have increased levels of CLK–CYC direct target gene mRNAs as well as a short period, implicating circadian transcription in period determination. A more detailed examination of reporter gene expression in CYC-VP16–expressing flies suggests that the short period is due at least in part to a more rapid transcriptional phase. Importantly, the behavioral effects require a period (per) promoter and are therefore unlikely to be merely a consequence of generally higher PER levels. This indicates that the CLK–CYC-VP16 behavioral effects are a consequence of increased per transcription. All of this also suggests that the timing of transcriptional activation and not the activation itself is the key event responsible for the behavioral effects observed in CYC-VP16-expressing flies. The results taken together indicate that circadian transcription contributes to core circadian function in Drosophila.
Perinatal blood loss.

1. Richard A. Molteni 1. Associate Professor of Pediatrics, University of Utah Medical Center, 50 North Medical Dr Salt Lake City, UT 84132 In recent years a great deal of attention has been paid to the evaluation and treatment of conditions characterized by red blood cell excess (polycythemia). The debatable practice of routine newborn hematocrit screening was initiated and perpetuated by the still uncertain short-term and long-term complications of polycythemia and its commonly associated state of hyperviscosity. Previously unsuspected anemia is often identified during this same screening process. Unless profound (leading to hypovolemic shock) or associated with more visible signs of hemolysis (jaundice), the etiology of this state of diminished red blood cell mass is often ignored or evaluated incompletely. This review focuses on the effects of anemia in the fetus and neonate, discusses mechanisms of fetal red blood cell production, and provides a basic diagnostic approach for the clinician when anemia is recognized in the neonatal period. PHYSIOLOGIC EFFECTS OF RED CELL REDUCTION Tissue Oxygen Delivery Maintenance of adequate red blood cell numbers can be even more critical during fetal life than during the postnatal period. The fetus, dependent upon maternal oxygen sources, cannot raise tissue oxygen delivery acutely by increasing placental oxygen transfer, even when its red blood cell numbers are decreased. Total oxygen content (sum of oxygen dissolved in plasma and bound to hemoglobin) of the blood is dependent upon both the partial pressure of oxygen (Pao2) and the quantity of hemoglobin available.
Thumb metacarpophalangeal joint ulnar collateral ligament repair with condylar shaving.

Introduction Injuries to the ulnar collateral ligament (UCL) are relatively common and are best treated in the acute setting. The acute version of this injury can often be repaired primarily but in the chronic setting the ligamentous remnants are often retracted making this method of repair difficult. We present a novel alternative approach for UCL repair after chronic injuries or difficult acute injuries. Methods We describe the procedure and postoperative results. A standard S-shaped incision over the dorsal ulnar aspect of the thumb is used. The adductor aponeurosis is identified and separated from the joint capsule. A proximally based and distally based rectangular flap containing the UCL remnants is elevated exposing the metacarpophalangeal joint. A burr is used to shave the condyles on the ulnar aspect of the metacarpal and proximal phalanx. The joint is stabilized with a Kirschner wire. A suture anchor is used to secure the proximally based flap. The distal flap is secured on top of this using the same sutures from the anchor. The repaired ligament is secured to the volar plate on the palmar aspect using a 4-0 Ethibond. Results This surgical technique has been used extensively by the senior authors; we present a representative case. At 3 months the patient had a grip strength of 85 lbs, tripod pinch of 12 lbs, lateral pinch of 5 lbs, 2-point pinch of 6 lbs, active range of motion at metacarpophalangeal joint of 0 to 70 and passive range of motion at the metacarpophalangeal joint MP of 0 to 85. Conclusion Despite a number of options for ligament reconstruction many of the described methods of repair are relatively complex and involve derangement of local tissues. We offer a novel adjunct to current methods of UCL reconstruction in which condylar shaving makes repair much more simple and avoids the use of a tendon graft. This approach provides a shorter course for the retracted UCL remnants allowing primary repair in the chronic setting and in the difficult acute repair.
Percutaneous Access to the Vertebral Bodies: A Video and Fluoroscopic Overview of Access Techniques for Trans-, Extra-, and Infrapedicular Approaches

Objective With increasing popularity of percutaneous spinal access for minimally invasive spinal neurosurgery, the treatment paradigm has shifted from open approaches to vertebroplasty or kyphoplasty for degenerative spinal disease and vertebral compression fractures. Addressing the challenges of this shift, we integrate the fluoroscopic studies of these percutaneous approaches with the three-dimensional surgical anatomy. Step-by-step techniques are illustrated in video demonstrations that highlight the nuances of effective percutaneous access during spinal surgeries for vertebral compression fractures and pedicle screw fixation. Methods Imaging guidelines, approach planning, surgical techniques, and relevant anatomical features are noted for the transpedicular, lumbar extrapedicular, and thoracic extra- and infrapedicular approaches. Video clips and accompanying fluoroscopic images highlight the critical steps. Subtle refinements unique to each percutaneous access are presented related to skin incision, needle trajectory, and cement deposition. Results With the transpedicular approach (popular technique for vertebroplasty and pedicle screw placement), safe access requires accurate interpretation of the fluoroscopic anatomy, specifically identification of the target vertebral body in true anterior-posterior and lateral planes. The transpedicular trajectory uses the slight inferior and medial orientation of the pedicle followed anteriorly. The lumbar extrapedicular approach uses an oblique trajectory anterior to the transverse process at the level of the pedicles. A thoracic approach uses the potential space between the rib head, transverse process, and pedicle. The infrapedicular approach, which allows greater flexibility in its medial angulation but at the expense of the bony confines of the thoracic extrapedicular approach, takes advantage of the narrow-waisted thoracic laminae. Conclusions With an appreciation for the standard anatomical landmarks, fluoroscopic views, and avenues of approach, percutaneous access techniques can be safely and effectively applied to many spinal procedures.
Multiple populations of serotonin receptors may modulate the behavioral effects of serotonergic agents

In order to establish a functional role for the various populations of serotonin (5-HT) receptors, behavioral studies have been conducted over the past decade with serotonergic agonists and antagonists. And, although there is reason to believe that certain behavioral effects may be mediated via particular populations of 5-HT receptors, evidence now suggests that some serotonin-mediated behaviors may be modulated by the interaction of serotonergic agents at multiple subtypes of 5-HT receptors. The generality of these effects, and the exact mechanism(s) by which they occur, have yet to be elucidated. Nevertheless, over the past year, results from several different laboratories provide a growing recognition of this novel phenomenon.
Assay of heparin. II. Influence of various factors on potency and clotting concentration of heparin

Abstract In assaying commercial samples of heparin no difference in potency was found when tested on either fresh or frozen beef or sheep plasma nor was any seasonal influence noted. Potency estimations were also unaffected by assay time or type of end point employed. The actual amount of heparin needed to inhibit coagulation is altered, however, by such factors as the state of the plasma (fresh or frozen), the aging of plasma at room temperature, the assay temperature, assay time, and type of end point. Small variations in calcium from the stoichiometrical equivalent of the citrate anticoagulant do not affect the heparin requirement. However, smaller amounts of calcium result in a lowered heparin requirement. The conditions specified for an assay must be rigidly adhered to, particularly in regard to treating the standard and unknown exactly alike.
Evolving Resources to Support Improvement of Pain and Symptom Control at End of Life

Resources to support pain and symptom control in palliative care and to improve the culture within which end of life care is delivered are evolving rapidly. This report reviews several major innovations including collaborations and consortia, reports, newsletters, and a new electronic journal. These innovations come from work of the Institute of Medicine, Last Acts, Innovations in Care at the End-of-Life, Project Death in America, Americans for Better Care of the Dying, Community State Partnerships to Improve Care at the End of Life and Supportive Care of the Dying.
The Arab American National Museum: Cultural Competency Training in Post-9/11 America.

AbstractIn the aftermath of the tragic events of September 11th, 2001, Arab and Muslim Americans, already suffering from negative stereotyping, find themselves subject to greater hostility. The Arab American National Museum (AANM) has discovered that professional development and cultural competency training opportunities for law enforcement personnel, educators, health professionals, and government officials dispels myths, alleviates fears, and prepares professionals. This article addresses how the AANM has successfully established itself as a resource for cross-cultural bridge building through these programs.
Identification of IgA Binding Structures in Skin of Patients with Dermatitis Herpetiformis

Immunoelectronmicroscopic and ultrastructural identification of the structures which bind IgA in skin of patients with dermatitis herpetiformis (DH) reveals them to be, in part, a complex of fibrillar components which are covered with amorphous substances. One of the fibers has a diameter of 80–130 A and appears to be tubular, resembling dermal microfibrillar bundles or microtubular elements of elastic fibers. The structures, at times, are associated with the dermal microfibrillar bundles and are found within an elastic fiber system which is in close proximity to the dermal-epidermal junction. Taken together, these findings suggest that the structures which bind IgA are unique to DH and might be a part of an abnormal dermal microfibrillar bundleelastic fiber system.
Serologic findings in autoimmune hemolytic anemia associated with immunoglobulin M warm autoantibodies.

Background Autoimmune hemolytic anemia (AIHA) associated with immunoglobulin M (IgM) warm autoantibodies is unusual but often severe, with more fatalities than other types of AIHA. Diagnosing this type of AIHA can be difficult because routine serologic data are not always informative. Study design and methods Forty-nine cases of IgM warm AIHA in 25 years were studied by serologic methods. Results Routine direct antiglobulin tests (DATs) detected red blood cell (RBC)-bound C3 in 90 percent of cases (65% had C3 but no immunoglobulin G [IgG] on their RBCs) and IgG in 24 percent. IgM was detected on 29 of 47 (62%) patients' RBCs; RBC-bound IgM was detected in 14 of 47 cases by a tube DAT method and in an additional 15 of 21 (71%) cases using fluorescein isothiocyanate anti-IgM and flow cytometry. Eighty-one percent of eluates from patients' RBCs reacted. Warm autoagglutinins were present in 94 percent of serum samples; untreated and enzyme-treated RBCs were hemolyzed at 37 degrees C by 13 and 65 percent of serum samples, respectively. Most agglutinins were optimally reactive at 30 to 37 degrees C. Patients' RBCs were spontaneously agglutinated in 78 percent of cases; washing with 37 degrees C saline or treating RBCs with dithiothreitol resolved this problem. Clear specificity of autoantibody was defined in 35 percent of serum samples. Conclusion IgM warm AIHA can be confused with cold agglutinin syndrome and "mixed/combined"-type AIHA; a serologic workup by a specialist reference laboratory can help with the diagnosis.
Quality of monitoring of stochastic events by periodic & proportional-share scheduling of sensor coverage

We analyze the quality of monitoring (QoM) of stochastic events by a periodic sensor which monitors a point of interest (PoI) for q time every p time. We show how the amount of information captured at a PoI is affected by the proportion q/p, the time interval p over which the proportion is achieved, the event type, and the stochastic event arrival dynamics and staying times. The periodic PoI sensor schedule happens in two broad contexts. In the case of static sensors, a sensor monitoring a PoI may be periodically turned off to conserve energy, thereby extending the lifetime of the monitoring until the sensor can be recharged or replaced. In the case of mobile sensors, a sensor may move between the PoIs in a repeating visit schedule. In this case, the PoIs may vary in importance, and the scheduling objective is to distribute the sensor's coverage time in proportion to the importance levels of the PoIs. Based on our QoM analysis, we optimize a class of periodic mobile coverage schedules that can achieve such proportional sharing while maximizing the QoM of the total system.
Editor’s Note: Focus on QEEG…and EEG

Recognition of the growing interest in Quantitative EEG led me to extend an invitation to the Neurofeedback Division of the Association for Applied Psychophysiology and Biofeedback to assemble a series of papers focusing on this topic. Jonathan Walker accepted this invitation and solicited the contributions included in this issue, which range from a controlled trial to collections of clinical cases, as well as methodological commentary. It is my hope that this brief series will stimulate further interest in this topic, leading to more rigorous tests of the preliminary notions advanced herein. Around the same time the above-mentioned papers were being assembled, the journal began to receive a number of papers addressing Autism Spectrum Disorders, also known as Pervasive Developmental Disorders. As the later name implies, these conditions can cause severe and pervasive impairments in cognition, affect, language, and ability to relate to one another. To date, no single treatment or treatment package is universally accepted. Growing recognition of the importance of research in this area led the National Institutes of Health recently to award more than 50 grants on this topic, totaling more than $65 million dollars, supported by the American Recovery and Reinvestment Act (Recovery Act) fund. Three papers addressing Autism Spectrum Disorders are included in this issue—2 comprehensive reviews and 1 large-scale clinical replication series. All include a major focus on EEG assessment and treatment. Although the review papers address similar topics, they were found different enough to warrant each being published. It is my further hope that these papers, and others soon to follow, will encourage others to become involved in this important, but clearly understudied, area of research.
A complementary approach to bioterrorism prevention

Michael Mair, MPH, is a senior research assistant at the Center for Civilian Biodefense Strategies, Johns Hopkins Bloomberg School of Public Health. Julie Samia Mair, JD, MPH, is an assistant scientist in the Department of Health Policy and Management at Johns Hopkins Bloomberg School of Public Health and a core faculty member of the Center for Law and the Public’s Health at Johns Hopkins and Georgetown Universities.1
Why is one of the periodical cicadas (Magicicada septendecula) a comparatively rare species

. 1 The same woodland rarely supports two different broods of 17-year cicadas, and never two that appear in successive years. Theoretically, this is because a build-up of predators, generated by the leading brood, would eliminate the lagging one, or because nymphs of the lagging brood would suffer a competitive disadvantage, or both. 2 Nevertheless, substantial numbers of 17-year cicadas of all three species (Magicicada septendecim, M.cassini and M.septendecula) did appear in Grant County, Kentucky, in 1974 (Brood XIV, expected) and 1975 (not expected). This is interpreted to mean that many individuals delayed their emergence until the eighteenth year. 3 Dissected eggnests show that the expected build-up of hymenopterous egg parasitoids failed to occur, although there may have been a build-up of dipteran parasitoids, which may leave no trace in the eggnest. 4 Excavated young nymphs show that establishment rate was poorer in 1975 than in 1974, which is attributed to nymphal competition. 5 Identification of eggnests from the two years shows that one of the species (M.septendecula, which is usually the rarest in mixed-species populations) is much more susceptible to delaying its development by a year than are the other two species. 6 It is predicted that the 1975 emergence will produce no adult progeny, i.e. that there will be no emergence in 1992. 7 The sporadic occurrence of this phenomenon, other factors being equal, would be sufficient to explain the comparative rarity of M. septendecula, or even its local extinction. 8 Historical records from northern Illinois show frequent emergences one year behind schedule. These delayed individuals never produce progeny that survive to the next generation. M.septendecula is absent from northern Illinois and indeed absent from the northern areas of all periodical cicada broods in the northern part of the range.
Development of occupational aspirations in early Korean adolescents: a multiple-group latent curve model analysis

The complex phenomenon of intraindividual and interindividual differences in the development of occupational aspirations and factors influencing this development were examined in a longitudinal sample of 5,727 Korean adolescents over a 4-year period. A downward trajectory of occupational aspirations from junior high school to the first year of high school was found. Rate of change in expressed aspirations was different for men and women. Potentially important initial differences in occupational aspirations development, based on curriculum track, were also detected.
Alternating groups as quotients of two generator groups

Abstract Graham Higman has proved that for sufficiently large n , the group A n is a homomorphic image of the triangle group Δ (2, 3, l ) where l = 7. Later, his result was generalized by proving it for all l > 7. In this paper we have shown that for sufficiently large n , the group A n is a homomorphic image of Δ (2, k , l ) where l ≥ 5 k − 3 and k (≥6) is even.
The initial value problem for a nonlinear nonuniform parabolic equation

The initial value problem for a nonlinear nonuniform parabolic equation is studied The coefficient of the nonlinear term is defined by the operator (−Δ)α/2. The goal is to prove the global existence of a smooth solution for any smooth initial data. Conditions which guarantee the above result are given. They involve the parameter α and the dimension n.
Isocratic separation of estrogen conjugates on deae-sephadex

Abstract Mixtures of estrogen conjugates containing estrone-3-glucosiduronate, 17β-estradiol-3-glucosiduronate, 17β-estradiol-17-glucosiduronate, estrone-3-sulfate and 17β-estradiol-3-sulfate have been separated on DEAE-Sephadex resin by isocratic elution using NaCI concentrations ranging from 0.05M to 0.4M. The results indicate that an NaCI gradient is not necessary for the Chromatographic separation of these estrogen conjugates. An NaCl concentration of 0.05M was adequate to separate the various monoglucosiduronates and sulfates. Isocratic elution of the columns with or without a possible stepup in the salt concentration was shown to give a higher resolution of estrogen conjugates in a more convenient volume than a gradient elution. For ideal chromatography of estrogen conjugates on a DEAE-Sephadex column, isocratic elution with 0.05 or 0. IM NaCl is preferred for the separation of monoglucosiduronates and 0.2 or 0.25M NaCl for the separation of sulfate conjugates. Contrary to current expectations, the molarity at which a particular conjugate elutes in a gradient mode does not bear a consistent relationship to the structure of the conjugate. However, the holdback volume in the isocratic mode may be used for identification purposes. When holdback volume was plotted against molarity, separate curves were obtained for each of the above mentioned conjugates. Tests of fit were carried out using a number of models. The best fit was obtained using the simple model y = a + b 1 x where the independent variable, x, is the molarity; the dependent variable, y, is the volume and a and b are the intercept and slope respectively. Each curve fitted the model, but the values for a and b were significantly different. Using this model, a simple and predictable relationship between molarity and holdback volume can be demonstrated for each of the estrogen conjugates. The advantages of the isocratic mode of elution over gradient elution are discussed.
On the ideal market structure for third-party purchasing of health care

Abstract The ideal market structure would give each medical care organization effective incentives to produce maximum value for money for enrolled subscribers. It should be based on integrated financing and delivery systems—partnerships that link doctors, hospitals and insurers—with per capita prepayment, with providers at risk for cost of care and cost of poor quality, publicly accountable for quality and per capita costs. The ideal market structure must be managed by active intelligent collective purchasing agents, called sponsors, that contract with health care systems and set the rules of competition. Sponsors structure and manage the enrollment process; they create price-elastic demand; they manage risk selection; and they create and administer equitable rules of coverage. Microeconomic theory tells us what sponsors should do to get the market incentives right. There is no comparable political theory to tell us how their boards of directors should be constituted. The paper offers a list of undesirable political arrangements to be avoided and some desirable features of sponsor constitutions.
Learning Goals in an Exemplary Science Teacher's Practice: Cognitive and Social Factors in Teaching for Conceptual Change.

The conversations of elementary school students in the classroom of Sister M. Gertrude Hennessey have captured the attention of science educators, scientists, and cognitive psychologists. Research studies documenting student outcomes have been presented in professional journals and at professional meetings. While there are many unique aspects of learning that the students in this classroom exhibit during conversations with one another and their teacher, the extraordinary performance of these students inevitably raises the question: How does Sister Gertrude do it? What are significant components of her instruction that support the student outcomes reported in studies of her students? In this article, we provide a detailed account of her instruction, an account that can help us understand how she facilitates conceptual change learning through a carefully chosen set of learning goals. Through instruction that established these learning goals, Sister facilitated a learning environment in which students spoke about their ideas, offered justifications for ideas, recognized the limitations of an idea, and negotiated knowledge claims in ways similar to some of those in the scientific community. In presenting this case study, we are conscious of the implications that answers to our questions about Sister Gertrude's instruction could have for other teachers as well. In other words, we are interested in whether the learning that takes place in Sister's classroom is the product of a unique and singular environment, or whether the instructional principles she uses, once incorporated into the practices of other teachers, might result in similar student outcomes. © 1999 John Wiley & Sons, Inc. Sci Ed83:738–760, 1999.
Compression-Designs of SAR Imagery Used as Prior Knowledge

The signal to interference plus noise ratio (SINR) performance of SAR imagery knowledge-aided (KA) airborne moving target indicator (AMTI) radar subjected to severely taxing environmental disturbances is investigated for radar-blind and radar-seeing highly compressed SAR imagery. Radar-seeing schemes are found to greatly outperform radar-blind techniques.
Dielectrophoretic force calculation

Abstract The dielectrophoretic force on insulating and finite conducting dielectric spheres immersed in a dielectric fluid medium and subjected to a non-uniform electric field is calculated using various methods. The first to be considered is the force exerted by a point charge on an insulating dielectric sphere. Next, the total force on a finite conducting dielectric sphere in a finite conducting dielectric fluid is determined. In this latter case, both conduction (free) charge and polarization (bound) charge contribute tothe net effective dipole moment. The various derivations illuminate the conventional approximations used in the dielectrophoretic model. The relationship of free and bound surface charge to the effective dipole moment, to the induced dipole moment and to the total dielectrophoretic force is clarified.
Biased estimation of symbol timing offset in OFDM systems

For orthogonal frequency division multiplexing (OFDM) receivers, the mutual orthogonality of the subcarriers is preserved only if the estimated symbol timing error lies in the lock-in region. This paper is the first to investigate adding a bias to coarse symbol time offset estimators, and analyze its performance in terms of the lock-in probability. The optimal value of the bias term is derived for unbiased symbol time offset estimators, and it is shown through simulation that the biased estimator achieves a significantly higher lock-in probability than the unbiased estimator.
Prognostic indicators from radionuclide angiography in medically treated patients with coronary artery disease

The purpose of this investigation was to determine which variables obtained when performing radionuclide angiography predict subsequent survival or total events (cardiovascular death or nonfatal myocardial infarction) in stable patients with symptomatic coronary artery disease (CAD). Univariable and multivariable analyses of 6 variables, including ejection fraction (EF) at rest and exercise, change in EF with exercise, development of ischemic chest pain or electrocardiographic changes, left ventricular (LV) wall motion abnormalities and exercise time were examined in 386 patients followed up to 4.5 years. Univariate analyses revealed that the exercise EF was the variable most closely associated with future events (p less than 0.01), followed by EF at rest, wall motion abnormalities and exercise time. Multivariable analyses revealed that once the exercise EF was known, no other radionuclide variables contributed independent information about the likelihood of future events. Multivariable analyses also revealed that the exercise EF describes much of the prognostic information of coronary anatomy. Our findings suggest that the radionuclide angiogram is useful in predicting future events in patients with stable CAD, although examination in conjunction with other clinical descriptors will be necessary to further quantify this contribution.
The effects of estrogen on skeletal calcium metabolism and on plasma parameters of vitellogenesis in the male, three-toed box turtle (Terrapene carolina triunguis)

The box turtle (Terrapene carolina triunguis) does not appear to have evolved a mechanism for secondary bone formation similar to Aves inasmuch as several parameters of bone calcium metabolism were unaffected by estrogen treatment. This suggests that reproduction does not constitute a substantial stress to the calcium stores of the female, even though the box turtle is a terrestrial species for which a supply of calcium may be limited. However, the dermal bone of the shell of the box turtle appears to take up calcium at a rate equivalent to that of endoskeletal bones, suggesting that it participates in mineral homeostasis at least to the extent of other osseous elements. Calcium metabolism in the turtle may be unique among vertebrates in this respect. Estrogen treatment of male box turtles results in the appearance of a specific plasma protein in parallel with pronounced changes in plasma calcium and magnesium, suggesting the induction of vitellogenin. The magnitude of the vitellogenic response may have a seasonal component.
Magnetic phase diagram of a five-orbital Hubbard model in the real-space Hartree-Fock approximation varying the electronic density

Using the real-space Hartree-Fock approximation, the magnetic phase diagram of a five-orbital Hubbard model for the iron-based superconductors is studied varying the electronic density $n$ in the range from five to seven electrons per transition metal atom. The Hubbard interaction $U$ is also varied, at a fixed Hund coupling $J/U=0.25$. Several qualitative trends and a variety of competing magnetic states are observed. At $n=5$, a robust G-type antiferromagnetic insulator is found, in agreement with experimental results for BaMn${}_{2}$As${}_{2}$. As $n$ increases away from 5, magnetic states with an increasing number of nearest-neighbors ferromagnetic links become energetically stable. This includes the well-known C-type antiferromagnetic state at $n=6$, the E-phase known to exist in FeTe, and also a variety of novel states not found yet experimentally, some of them involving blocks of ferromagnetically oriented spins. Regions of phase separation, as in Mn oxides, have also been detected. Comparison to previous theoretical investigations indicate that these qualitative trends may be generic characteristics of phase diagrams of multi-orbital Hubbard models.
Efficient computation of higher order frequency response functions for nonlinear systems with, and without, a constant term

The behaviour of a nonlinear system can be profoundly affected by the presence of a constant or dc term in the system governing equation. These changes are reflected in the nonlinear frequency response characteristics of the system which provide a powerful insight into the system's dynamics. In this article, a new and efficient algorithm is presented for computing the higher order Volterra frequency response functions from nonlinear time-domain models that may contain a constant term. A comparison with previous methods is included to demonstrate the significant gains in computational efficiency that are achieved using the new method. The algorithm is applicable to systems modelled by nonlinear differential, or difference, equations and is easily automated. Several examples are used to illustrate the method, and to highlight the importance of dc terms in nonlinear system analysis.
A relationship between reduced nucleus accumbens shell and enhanced lateral hypothalamic orexin neuronal activation in long-term fructose bingeing behavior.

Fructose accounts for 10% of daily calories in the American diet. Fructose, but not glucose, given intracerebroventricularly stimulates homeostatic feeding mechanisms within the hypothalamus; however, little is known about how fructose affects hedonic feeding centers. Repeated ingestion of sucrose, a disaccharide of fructose and glucose, increases neuronal activity in hedonic centers, the nucleus accumbens (NAc) shell and core, but not the hypothalamus. Rats given glucose in the intermittent access model (IAM) display signatures of hedonic feeding including bingeing and altered DA receptor (R) numbers within the NAc. Here we examined whether substituting fructose for glucose in this IAM produces bingeing behavior, alters DA Rs and activates hedonic and homeostatic feeding centers. Following long-term (21-day) exposure to the IAM, rats given 8–12% fructose solutions displayed fructose bingeing but unaltered DA D1R or D2R number. Fructose bingeing rats, as compared to chow bingeing controls, exhibited reduced NAc shell neuron activation, as determined by c-Fos-immunoreactivity (Fos-IR). This activation was negatively correlated with orexin (Orx) neuron activation in the lateral hypothalamus/perifornical area (LH/PeF), a brain region linking homeostatic to hedonic feeding centers. Following short-term (2-day) access to the IAM, rats exhibited bingeing but unchanged Fos-IR, suggesting only long-term fructose bingeing increases Orx release. In long-term fructose bingeing rats, pretreatment with the Ox1R antagonist SB-334867 (30 mg/kg; i.p.) equally reduced fructose bingeing and chow intake, resulting in a 50% reduction in calories. Similarly, in control rats, SB-334867 reduced chow/caloric intake by 60%. Thus, in the IAM, Ox1Rs appear to regulate feeding based on caloric content rather than palatability. Overall, our results, in combination with the literature, suggest individual monosaccharides activate distinct neuronal circuits to promote feeding behavior. Specifically, long-term fructose bingeing activates a hyperphagic circuit composed in part of NAc shell and LH/PeF Orx neurons.
Amplification of acoustic surface waves by means of a broadband hybrid-junction transducer and negative-resistance circuits

The letter describes an interdigital surface-wave transducer with properties closely analogous to those of an electromagnetic quadrature hybrid junction. If the two electrical ports of such a hybrid-junction transducer are terminated in appropriate negative resistances, transmission gain is observed for an incident acoustic surface wave.
Effects of Positive Peer Reporting (PPR) on Social Acceptance and Negative Behaviors Among Peer-Rejected Preschool Children

Positive peer reporting (PPR) is a peer-mediated intervention that involves teaching and rewarding peers for providing descriptive praise during structured daily sessions. PPR has been used in residential facilities to improve social acceptance, increase prosocial behaviors, and decrease negative interactions of youth identified as peer rejected. Few studies have evaluated the use of PPR in general education classrooms with younger students. The purpose of this investigation was to evaluate the effectiveness of PPR with preschool children. PPR was implemented in Head Start classrooms in order to evaluate its effectiveness in improving social acceptance and decreasing negative behaviors of three children who were identified as being peer rejected. An ABA multiple-baseline, across-participants design with a followup probe was used to evaluate the effectiveness of PPR. For 2 of the 3 children, PPR reduced the negative behaviors in the classroom setting. One week of PPR also increased the social acceptance ra...
A general water supply planning model: Evaluation of decentralized treatment

Increasing population, diminishing supplies and variable climatic conditions can cause difficulties in meeting water demands; especially in arid regions where water resources are limited. Given the complexity of the system and the interactions among users and supplies, a large-scale water supply management model can be useful for decision makers to plan water management strategies to cope with future water demand changes. It can also assist in deriving agreement between competing water needs, consensus and buy-in among users of a proposed long-term water supply plans. The objective of this paper is to present such a general water supply planning tool that is comprised of modular components including water sources, users, recharge facilities, and water and wastewater treatment plants. The model is developed in a system dynamics simulation environment that helps users easily understand the model structure. The model was applied to a realistic hypothetical system and simulated several possible 20-year planning scenarios. In addition to water balances and water quality analyses, construction and operation and maintenance of system components costs were estimated for each scenario. One set of results demonstrates that construction of small-cluster decentralized wastewater treatment system could be more economical than a centralized plant when communities are spatially scattered or located at steep areas where pumping costs may be prohibitive.
Molecular beam measurements of nuclear moments before magnetic resonance. Part I: I.I. Rabi and deflecting magnets to 1938

Summary Investigation of the origin and function of three magnets from I. I. Rabi's laboratory at Columbia University leads to a closer inquiry into the early history of molecular beam evaluations of the angular momenta and magnetic moments of atomic nuclei than has been undertaken heretofore. The resulting insights into the background and the course of Rabi's research programme would probably not have occurred without the orientation enforced by these artifacts.
Citrulline Can Preserve Proliferation and Prevent the Loss of CD3 ζ Chain Under Conditions of Low Arginine

Background: Arginine depletion by the enzyme Arginase I, decreases expression of the TCR ζ chain preventing T-cell activation and causing T-cell dysfunction. We hypothesized that citrulline could substitute for arginine under conditions of increased arginase expression. Thus, the goal was to establish a possible mechanism of how citrulline could overcome arginine depletion caused by arginase. Methods: Jurkat cells were cultured, with or without arginase, in media containing different amino-acid constituents: complete RPMI containing arginine (C-RPMI) (arginine), Arginine-Free-RPMI (Arg-Free RPMI) and Citrulline-containing RPMI (Cit RPMI). Incorporation of citrulline was measured via uptake of 3H-citrulline, whereas proliferation was measured via3H-thymidine incorporation. ζ Chain was analyzed by 2-color flow cytometry. Argininosuccinate synthase (AS) and argininosuccinate lyase expression was detected using Northern blots, RT-PCR, and Western blots. Results: Jurkat cells exhibited a significant decrease i...
Synthesis, characterization, and application of fluorescence sensing lipobeads for intracellular pH measurements.

This paper describes the synthesis and characterization of micrometric phospholipid-coated polystyrene particles, named lipobeads, with pH-sensing capability and their application for intracellular pH measurements in murine macrophages. The phospholipids used to coat the particles are labeled with fluorescein (a pH-sensitive dye) and tetramethylrhodamine (a pH-insensitive dye), which serves as a referencing fluorophore for increased accuracy of the pH measurements. The synthesis of the pH-sensing lipobeads is realized by the covalent attachment of the fluorescent phospholipids to the surface of carboxylated polystyrene particles. The pH dynamic range of the sensing particles is between 5.5 and 7.0 with a sensitivity of 0.1 pH unit. The excitation light intensity is reduced to minimize photobleaching of the fluorescein−phospholipid conjugates. The fluorescent lipobeads are used to measure the pH in single macrophages. The lipobeads are ingested by the macrophages and directed to lysosomes, which are the ce...
Numerical determination of short-period Trojan orbits in the restricted three-body problem

Short period orbit calculations around equilateral libration points in plane restricted three-body problem
Recent developments in numerical techniques for treating material interfaces (abstract)

The Arbitrary-Lagrangian Eulerian Technique (ALE)1 provides a framework in which one can regrid individually different regions of a calculational mesh. In particular, one can treat an interface between materials as a Lagrangian line and rezone the remaining parts of the grid with some appropriate algorithm. This keeps material from being fluxed across the interface and avoids the problem of mixed cells with the attendant difficulty of obtaining pressures for such cells. At the same time it maintains some degree of regularity in the regions away from the interface.