cssi/SciSciGPT-SciSciNet huggingface dataset:
Smart current source gate driver for fast switching and cross-talk suppression of SiC MOSFET

Wide band gap device, like SiC and GaN, have high switching speed potential. However, the actual speed in practical use is limited by the gate loop parasitic and the interaction between high side switch and low side switch in a single phase-leg configuration known as cross-talk. This paper proposes an isolated current source gate driver (CSGD) with cross-talk suppression capability to take full advantage of the inherent high switching speed ability of WBG device. The current source is better than voltage source since it can ignore the gate loop parasitic inductance. And by applying variable gate voltage, the cross-talk problem can be mitigated. LTspice simulation and experiment results based on 1.2kV Wolfspeed SiC MOSFET are shown in this paper to verify the proposed gate driver.
Role of follow-up CT scans in the management of traumatic pediatric epidural hematomas

Management of pediatric epidural hematoma (PEDH) ranges from observation to emergent craniotomy. Guidelines for management remain poorly defined. More so, serial CT imaging in the pediatric population is often an area of controversy given the concern for excessive radiation as well as increased costs. This work aims to further elucidate the need for serial imaging to surgical decision-making. A prospectively maintained single-institution trauma database was reviewed at a level-1 trauma center to identify patients 18 years old and younger presenting with PEDH over a 10-year period. Selected charts were reviewed for demographic information, mechanisms of injury, neurologic exam, radiographic findings, and treatment course. Surgical decisions were at the discretion of the neurosurgeon on call, often in discussion with a pediatric neurosurgeon. Two hundred and ten records with traumatic epidural hematomas were reviewed. Seventy-three (35%) were taken emergently for hematoma evacuation. Of these, 18 (25%) underwent repeat imaging prior to surgery. One hundred and thirty-seven (65%) were admitted for observation. Seventy-two patients (53%) did not undergo repeat imaging. Sixty-five (47%) admitted for conservative management had at least one repeat scan during their hospitalization. Indications for follow-up imaging during conservative management included routine follow-up (74%), initial scan in our system following transfer (17%), neurological decline (8%), and unknown (1%). Thirteen patients (9%) were taken for surgery in a delayed fashion following admission. Twelve patients who went to surgery in a delayed fashion demonstrated progression on follow-up imaging; however, increase in hematoma size on repeat imaging was the sole surgical indication in only four patients (3%). There were no deaths related to the epidural hemorrhage or postoperatively, regardless of management, and all patients recovered to their pre-trauma baseline. Given that isolated hematoma expansion accounted for an exceptionally small proportion of operative indications, this data suggests changes seen on CT should not be solely relied upon to dictate surgical management. The benefit of obtaining follow-up imaging must be strongly considered and weighed against the known deleterious effects of excessive radiation in pediatric patients, let alone its clinical utility.
Defending Against Neural Network Model Stealing Attacks Using Deceptive Perturbations

Machine learning architectures are readily available, but obtaining the high quality labeled data for training is costly. Pre-trained models available as cloud services can be used to generate this costly labeled data, and would allow an attacker to replicate trained models, effectively stealing them. Limiting the information provided by cloud based models by omitting class probabilities has been proposed as a means of protection but significantly impacts the utility of the models. In this work, we illustrate how cloud based models can still provide useful class probability information for users, while significantly limiting the ability of an adversary to steal the model. Our defense perturbs the model's final activation layer, slightly altering the output probabilities. This forces the adversary to discard the class probabilities, requiring significantly more queries before they can train a model with comparable performance. We evaluate our defense under diverse scenarios and defense aware attacks. Our evaluation shows our defense can degrade the accuracy of the stolen model at least 20%, or increase the number of queries required by an adversary 64 fold, all with a negligible decrease in the protected model accuracy.
About becoming a teacher: by William Ayers, New York, Teachers College Press, 2019, 96 pp., $75 (hardback), ISBN 9780807761670; $24.95 (paperback), ISBN 9780807761496

Should I become a teacher? How can I build relationships with students and foster open communication with their parents? What do I value, and how do I enact those commitments in a classroom? These ...
CARE: compiler-assisted recovery from soft failures

As processors continue to boost the system performance with higher circuit density, shrinking process technology and near-threshold voltage (NTV) operations, they are projected to be more vulnerable to transient faults, which have become one of the major concerns for future extreme-scale HPC systems. Despite being relatively infrequent, crashes due to transient faults are incredibly disruptive, particularly for massively parallel jobs on supercomputers where they potentially kill the entire job, requiring an expensive rerun or restart from a checkpoint. In this paper, we present CARE, a light-weight compiler-assisted technique to repair the (crashed) process on-the-fly when a crash-causing error is detected, allowing applications to continue their executions instead of being simply terminated and restarted. Specifically, CARE seeks to repair failures that would result in application crashes due to invalid memory references (segmentation violation). During the compilation of applications, CARE constructs a recovery kernel for each crash-prone instruction, and upon an occurrence of an error, CARE attempts to repair corrupted state of the process by executing the constructed recovery kernel to recompute the memory reference on-the-fly. We evaluated CARE with four scientific workloads. During their normal execution, CARE incurs almost zero runtime overhead and a fixed 27MB memory overheads. Meanwhile, CARE can recover on an average 83.54% of crash-causing errors within dozens of milliseconds. We also evaluated CARE with parallel jobs running on 3072 cores and showed that CARE can successfully mask the impact of crash-causing errors by providing almost uninterrupted execution. Finally, We present our preliminary evaluation result for BLAS, which shows that CARE is capable of recovering failures in libraries with a very high coverage rate of 83% and negligible overheads. With such an effective recovery mechanism, CARE could tremendously mitigate the overheads and resource requirements of the resilience subsystem in future extreme-scale systems.
Microchain: A Light Hierarchical Consensus Protocol for IoT Systems

While the large-scale Internet of Things (IoT) makes many new applications feasible, like Smart Cities, it also brings new concerns on data reliability, security, and privacy. The rapid evolution in blockchain technologies, which relied on a decentralized, immutable, and distributed ledger system for transaction data auditing, provides a prospective solution to address many issues for IoT security. The blockchain and smart contract enabled security mechanism for IoT applications have attracted increasing interests from both academia and industry. However, integrating cryptocurrency-oriented blockchain technologies into IoT systems meets tremendous challenges on scalability, storage capacity, security, and privacy. Particularly, the performance of blockchain networks significantly relies on the performance of consensus mechanisms, e.g., in terms of data confidentiality, transaction throughput, and network scalability. In this chapter, following an in-depth review of state-of-the-art blockchain networks, the key matrix of designing consensus mechanism for IoT networks are identified in terms of throughput, scalability, and security. To demonstrate a case study on designing scalable, lightweight blockchain protocols for IoT systems; a Microchain framework is introduced and a proof-of-concept prototype is implemented in a physical network environment. The experimental results verify the feasibility of integrating the Microchain into IoT systems.
Technical Characteristics of Curriculum-Based Measurement With Students Who Are Deaf.

This study compared the reliability and validity of student scores from paper-pencil and e-based assessments using the "maze" and "silent reading fluency" (SRF) tasks. Forty students who were deaf and hard of hearing and reading between the second and fifth grade reading levels and their teachers (n = 21) participated. For maze, alternate form reliability coefficients obtained from correct scores and correct scores adjusted for guessing ranged from r = .61 to .84 (ps < .01); criterion-related validity coefficients ranged from r = .33 to .67 (most ps < .01). For SRF, reliability coefficients obtained from correct scores ranged from r = .50 to .75 (ps < .01); validity ranged from r = .25 to .72. Differences between student performance on paper-pencil and e-based conditions were generally non-significant for maze; significant differences between conditions for SRF favored the paper-pencil condition. Findings suggest that maze holds promise, with inconclusive results for SRF.
Behavior modification applied to training young deaf children.

Case histories of young hearing impaired children whose parents were enrolled in a parent home training program are described, and the developmental or behavioral management problems encountered are discussed. Some of the operant behavioral management procedures were particularly useful in (a) establishing effective discipline methods, (b) aiding the child's adjustment to prosthetic devices, and (c) dealing with problems related to additional handicapping conditions.
Cyberlaw will die and we will kill it

Cyberlaw is not Computers and the Law or Intellectual Property on the Internet. It is something far richer and more important. But cyberlaw is also ephemeral, a temporary mode of analyzing technological disruption in real time, until the day when intermediated networks become ubiquitous and cyberlaw will simply become “law.” At that time, cyberlaw will disappear, for the same reason that we no longer study “automobile law.” But for now, cyberlaw remains an important waystation, a central hub, in the study of emergent and powerful networks. This chapter uses teachings from major philosophers of the 18th, 19th, and 20th centuries — namely Hume, Nietzsche, and Heidegger — to reconcile and build upon the writings of some of today's leading cyber-scholars. Synthesizing these teachings, the chapter argues that cyberlaw should be understood as the study of how code, including intermediated networks, fosters disruptive feedback loops between power structures and prescriptive norms. Thus, although cyberlaw will someday merge into the general structure of the law, cyberlaw’s lasting legacy will be a methodology for studying the disruptive interplay of prescriptive norms and power structures, and how they create, destroy, and create again.
Coherent Optical and Spin Dynamics of Single 171Yb Ions Embedded In a Nanophotonic Cavity

We demonstrate coherent optical and spin control of single 171Yb ions in YVO4 nanophotonic resonators as a platform for quantum network nodes with spin-CPMG and optical-Ramsey coherence times of 33 ms and 390 ns respectively.
Fatal massive hemoptysis in a patient with delayed diagnosis of lung adenocarcinoma due to covid-19 pandemic

Since 2005, the number of lung cancer deaths in the United States has decreased1 due to advances in therapeutics and early detection. The COVID-19 pandemic has affected the prognosis of patients with lung cancer by delaying elective diagnostic procedures. A 66 year old man with past medical history of tobacco and polysubstance abuse initially presented to the emergency department with bilateral pedal edema. Chest imaging showed a right apical, spiculated cavitary mass. The patient missed his initial scheduled biopsy appointment and wanted to wait until pandemic subsided to reschedule. Ten weeks later, he presented to the hospital with rightsided sharp chest pain, associated with hemoptysis. CT-guided biopsy confirmed the diagnosis of adenocarcinoma. Cardiothoracic surgery was consulted, and the patient was initially planned to undergo surgical resection, however his functional status declined while pursuing pre-operative workup. He had progressive worsening hemoptysis, despite radiation treatment, requiring multiple transfusions of blood products. Interventional radiology performed bronchial artery embolization with interval improvement, however he progressed requiring endotracheal intubation with endobronchial blocker placement. Bleeding continued despite local treatment and family decided on palliative extubation. The COVID-19 pandemic contributed to delayed diagnosis of lung cancer. Analysis of 20 institutions in the United States showed a 46.8% decrease in new lung cancer diagnoses in April 2020 versus April 20192. In Korea, three university hospitals found a significant increase in patients with stage III-IV non-small cell lung cancer compared to prior years3. UK Health Service data modeling predict 4.8-5.3% increased lung cancer related mortality from pandemic delayed diagnosis5. In our case, the diagnosis was delayed due to the patient's uncertainty about accessing the medical system during a pandemic. This is not uncommon-the pandemic has been cited as a reason for refusing breast lesion biopsy4. Clinicians need to be aware of this fear and make efforts to reassure patients of the additional safety protocols in place. The American College of Surgery recommends that procedures for high risk cancers, such as lung cancer, are high acuity on the Elective Surgery Acuity Scale and diagnosis and staging to start treatment not be delayed, if feasible, during the pandemic6,7. Lung cancer may be uniquely impacted by pandemic staffing shortages as pulmonologists are deployed to surging ICUs. Our patient delayed care during a surge and did not have a risk/benefit discussion with a clinician. This highlights the need to develop additional patient outreach systems to ensure timely access to care during a pandemic.
Children With More Uncertainty in Their Intuitive Theories Seek Domain-Relevant Information.

How do changes in learners’ knowledge influence information seeking? We showed preschoolers (N = 100) uncertain outcomes for events and let them choose which event to resolve. We found that childre...
Isolating Cuts, (Bi-)Submodularity, and Faster Algorithms for Connectivity.

Li and Panigrahi [Jason Li and Debmalya Panigrahi, 2020], in recent work, obtained the first deterministic algorithm for the global minimum cut of a weighted undirected graph that runs in time o(mn). They introduced an elegant and powerful technique to find isolating cuts for a terminal set in a graph via a small number of s-t minimum cut computations. In this paper we generalize their isolating cut approach to the abstract setting of symmetric bisubmodular functions (which also capture symmetric submodular functions). Our generalization to bisubmodularity is motivated by applications to element connectivity and vertex connectivity. Utilizing the general framework and other ideas we obtain significantly faster randomized algorithms for computing global (and subset) connectivity in a number of settings including hypergraphs, element connectivity and vertex connectivity in graphs, and for symmetric submodular functions.
Entrepreneurial selection and use of legal counsel

Entrepreneurs starting new ventures will encounter a host of legal issues requiring consultation with an attorney on an episodic or ongoing basis. It is critical that careful attention be given to the attorney selection process to properly match the needs of the company with the credentials of the attorney.Additionally, options should be explored regarding the billing and payment methodologies the attorney is willing to entertain. The financial resources and cash flow of young companies will likely have a direct impact on the financial agreements entered into with legal counsel. Further, companies desirous of offering the attorney a stake in the company as full or partial payment for legal services need to be mindful of ethical restrictions applicable to the lawyer, as well as exceptions to the lawyerʼs malpractice coverage arising from his or her role with the company
Constitutional Courts as Lawmakers: A Commentary on the Lecture by Prof. Dr. Rupert Scholz, 'Constitutional Court Jurisdiction between Constitutional Law and Politics – Taking the German Federal Constitutional Court as an Example'

This paper was presented at the conference "The Mission and the Condition of the Supreme Court in the Contemporary Society" organized by the Ritsumeikan University, Kyoto, Japan, July 2013.The power of judicial review is the power to declare legislation (or action by the government) unconstitutional. Courts vested with this authority are properly denominated, "constitutional courts," whether judicial review is their exclusive function, as is the case with the German Federal Constitutional Court, or whether judicial review is but one of their functions, as is the case with the Supreme Court of the United States. The basic point of judicial review is to insulate constitutional or fundamental law from the pressures of the transitory needs perceived by the immediate majority operating under the constitution. It is true, though, that constitutional courts operate within the arena of politics, and it is also true that the decisions of constitutional courts, which are sometimes quite controversial, operate within political arena and often make law. I have developed a model that may lessen some of the “political” discomfort that arises from the practice of judicial review and make it more "legitimate." My model suggests that constitutional decisions should be premised on “durable principles,” by which I mean legal standards that can, by logic and analogy, be applied uniformly to a wide range of similarly situated cases. The articulation and application of those standards must be justified through a reasoned elaboration that takes into account the full sweep of constitutional text and tradition, considers the measure of evolving cultural norms, including new perspectives on established standards, and presents a fair and thorough consideration of real-world consequences. Taken together, this decisionmaking process represents an act of creation, but does so within the breadth of the existing constitution.
Architecture for Efficient Monitoring and Management of Sensor Networks

Wireless sensor networks are poised to increase the efficiency of many military and civil applications, such as disaster management. Typically sensors collect data about their surrounding and forward that data to a command center, either directly or through a base-station. Due to inhospitable conditions, these sensors are not always deployed uniformly in an area of interest and some sensors can be unreachable because they are too distant from the base-station or simply because there exist obstacles in their path. This paper focuses on reducing the sensitivity of the operation and monitoring of sensor networks to the ambiguity of the propagation model of the radio signal. We define ‘agent’ sensors, which monitor the health and relay messages to and from unreachable sensors. We form groups of sensors around these agents while considering the load on each agent. An energy-aware routing of data collected by and relayed by these agents is performed. Our approach localizes communication which reduces the amount of sensor energy expended in transmission, enables efficient monitoring of sensor resources and health status and allows optimal management of deployed sensors for increased network lifetime. The approach is validated by the simulation results.
Cytogenetic variability and kinetochore proteins. Comparison among populations derived from single-cell cultures.

Abstract This study reports comparative changes in five sub-lines obtained from a transformed culture of rat cerebral origin. Two of the lines were obtained from the original cell population while three others were raised from single-cell cultures. The comparative study was carried out on the DNA content and several cytogenetic parameters including variability in chromosome number, anaphase bridges, acentric fragments, chromosomes without detectable kinetochore proteins, and the frequency of micronuclei in these five lines. All cell lines, including the single-cell—derived clones expressed considerable variability in all aspects. One interesting aspect is the evolution of a chromosome with compound centromere, which is present only in two cell lines. The data indicate that the clone derived from a single cell does not maintain uniformity and even single cells have some sort of inherent potential to generate extreme variability. Some numerical variability may be attributed to a new phenomenon of a lack of kinetochore proteins seen on some chromosomes.
Dilatation and conformal invariance on null planes

It is proven that a relativistic scalar field whose null-plane restriction exists (Z 3 −1 < ∞), and which has c-number commutation relations there, transforms covariantly under dilatation and conformal transformations on a null plane. These transformations are thus unitarily implementable. The restriction of the conformal algebra to the null plane is discussed.
The Impact Of Capital and Remittance Flows on Economic Performance in MENA Countries

Using data for a sample of developing countries, we analyze the effects of external flows, namely migrants’ remittances and FDI flows, on real output growth, price inflation, and components of aggregate demand. The historical evidence indicates unstable patterns of FDI inflows to a sample of nine MENA countries. In contrast, remittances flows appear to be more stable over time in recipient countries. Except in Jordan, real GDP growth does not vary significantly with FDI inflows. Tunisia provides the only significant evidence of an increase in price inflation in response to FDI, which is coupled with a significant increase in private investment. FDI flows stimulate a higher increase in imports in Egypt. Remittances inflows appear, in general, a more important determinant of macroeconomic performance. Remittances inflows stimulate real output growth in Jordan and decrease price inflation in Egypt and Tunisia. The increase in growth in Jordan is coupled with an increase in private consumption, private investment, real exports and imports with respect to remittances inflows. Moreover, remittances increase export growth in Tunisia.
Taxation, Ethics of

In the United States, “tax ethics” are prescribed by law for federal tax purposes. Both taxpayers and their advisors must adhere to behavioral standards exquisitely detailed by statute and administrative regulation; failure to adhere to those standards, leads to the imposition of monetary (and even criminal) penalties and, in the case of providers, the possible loss of the right to represent clients before the taxing authorities. These standards have become more demanding over time. This entry provides a short description of the current statutory and regulatory regime. Keywords: covered opinions; listed transactions; more likely than not; disclosure; reasonable basis; negligence; substantial understatement; good faith; tax accrual workpapers; tax penalties
Understanding popout through repulsion

Perceptual popout is defined by both feature similarity and local feature contrast. We identify these two measures with attraction and repulsion, and unify the dual processes of association by attraction and segregation by repulsion in a single grouping framework. We generalize normalized cuts to multi-way partitioning with these dual measures. We expand graph partitioning approaches to weight matrices with negative entries, and provide a theoretical basis for solution regularization in such algorithms. We show that attraction, repulsion and regularization each contributes in a unique way to popout. Their roles are demonstrated in various salience detection and visual search scenarios. This work opens up the possibilities of encoding negative correlations in constraint satisfaction problems, where solutions by simple and robust eigendecomposition become possible.
Spatial-Angular Analysis of Displays for Reproduction of Light Fields

From a signal processing perspective, we examine the main factors defining the visual quality of autostereoscopic 3-D displays, which are beginning to reproduce the plenoptic function with increasing accuracy. We propose using intuitive visual tools and ray-tracing simulations to gain insight into the signal processing aspects, and we demonstrate the advantages of analyzing what we call mixed spatial-angular spaces. With this approach we are able to intuitively demonstrate some basic limitations of displays using anisotropic diffusers or lens arrays. Furthermore, we propose new schemes for improved performance.
Leveling Intermittent Renewable Energy Production Through Biomass Gasification-Based Hybrid Systems

The increased use of intermittent renewable power in the United States is forcing utilities to manage increasingly complex supply and demand interactions. This paper evaluates biomass pathways for hydrogen production and how they can be integrated with renewable resources to improve the efficiency, reliability, dispatchability, and cost of other renewable technologies. Two hybrid concepts were analyzed that involve co-production of gaseous hydrogen and electric power from thermochemical biorefineries. Both of the concepts analyzed share the basic idea of combining intermittent wind-generated electricity with a biomass gasification plant. The systems were studied in detail for process feasibility and economic performance. The best performing system was estimated to produce hydrogen at a cost of $1.67/kg. The proposed hybrid systems seek to either fill energy shortfalls by supplying hydrogen to a peaking natural gas turbine or to absorb excess renewable power during low-demand hours. Direct leveling of intermittent renewable electricity production is accomplished with either an indirectly heated biomass gasifier, or a directly heated biomass gasifier. The indirect gasification concepts studied were found to be cost competitive in cases where value is placed on controlling carbon emissions. A carbon tax in the range of $26–40 per metric ton of CO2 equivalent (CO2 e) emission makes the systems studied cost competitive with steam methane reforming (SMR) to produce hydrogen. However, some additional value must be placed on energy peaking or sinking for these plants to be economically viable. The direct gasification concept studied replaces the air separation unit (ASU) with an electrolyzer bank and is unlikely to be cost competitive in the near future. High electrolyzer costs and wind power requirements make the hybridization difficult to justify economically without downsizing the system. Based on a direct replacement of the ASU with electrolyzers, hydrogen can be produced for $0.27 premium per kilogram. Additionally, if a non-renewable, grid-mix electricity is used, the hybrid system is found to be a net CO2 e emitter.Copyright © 2010 by ASME
Vibronic coupling model for the magnetic dipole intensities of f-f transitions in octahedral lanthanide (III) complexes

The influence of vibronic coupling on the distribution of magnetic dipole intensity within the crystal field (f-f) spectra of lanthanide (III) complexes is examined. A formal theoretical model is developed which involves vibronically induced mixing among the f electron states of a centrosymmetric lanthanide(III) complex. Expressions are derived for calculating the magnetic dipole intensities associated with the one-phonon (gerade) vibronic lines in the f-f spectra of such a system, and order of magnitude calculations are presented for the octahedral (Oh ) TbCl6 3- complex in Cs2NaTbCl6. The calculated results indicate that the phonon-assisted magnetic dipole lines will have intensities two or three orders of magnitude less than the intensities associated with the pure (zero-phonon) magnetic dipole lines and the phonon-assisted electric dipole lines. However, the vibronically induced magnetic dipole transition moments are predicted to be sufficiently big to be of some importance in determining the chiropti...
Weakening partial orderings to lattice and semilattice orderings

A partial ordering on a set P can be weakened to an upper or lower semilattice ordering, respectively a lattice ordering, if and only if P is filtered in the appropriate direction(s).
Multigroup linear transport in the exponential half-space—I

Abstract A continuum set of singular eigenfunctions is constructed for the multigroup linear transport equation in the exponential atmosphere. This eigenfunction set is then shown to be complete for solving the subcritical half-space exit distribution problem.
Energy savings of water-heater retrofits: Evidence from Hood River

Abstract This paper assesses the energy savings of water-heater retrofits based on evidence from the Hood River Conservation Project (HRCP). It examines: (1) the electricity saved by the water-heater retrofit package as a whole; (2) the savings attributable to each of three individual measures (the water-heater wrap, pipe wrap and low-flow showerhead); (3) the impact of demographic and dwelling-unit characteristics upon savings; and (4) demand reductions during winter. Water-heater retrofits saved, on average, 540 kWh/year and were highly cost-effective. Each kWh of savings cost less than $0.04 (excluding the expense of the installer's visit), and the levelized cost over an assumed ten-year lifetime for the measures was only $0.0039/kWh. The water-heater retrofit was one of the most cost-effective components of the HRCP package. Its effectiveness was due largely to the water-heater pump. Water-heater demand also decreased at a cost of only $333 per kW.
Use of iodine-123 as a diagnostic tracer for neck and whole-body scanning in patients with well-differentiated thyroid cancer.

ABSTRACT Objective To determine whether 123I can be used as a safe and effective alternative tracer to 131I for imaging remnant tissue and for searching for metastatic lesions of well-differentiated thyroid cancer. Methods We studied a series of 16 patients (10 women and 6 men; 29 to 73 years of age) who had well-differentiated thyroid cancer and had undergone thyroidectomy and subsequent radioiodine treatment. Diagnostic 123I scans at 4, 24, and 48 hours after oral administration of 10 mCi (either preablation or postablation) were compared with the 5- to 7-day 131I posttherapy scans (doses, 75 to 200 mCi). Scans were jointly interpreted by nuclear medicine and endocrinology staff members. Results Of the 16 patients, 15 had concordant findings between the 123I diagnostic images and the corresponding 131I posttherapy scans. Only one patient had additional lesions noted on the posttherapy 131I scan, which was attributed to the higher dose the patient received during radioiodine treatment (a 6% discordance rate). This discordance, however, would not have changed the patient treatment. No advantage was noted for delayed imaging at 48 hours; the 24-hour images were satisfactory. The 123I scans were of higher resolution than the 131I scans. Conclusion Diagnostic 123I scans are an acceptable alternative to 131I scanning for whole-body imaging in well-differentiated thyroid cancer and demonstrate adequate imaging of thyroid remnant tissue or metastatic lesions from thyroid carcinoma comparable to the post-therapy scans. 123I scans also offer greater convenience to patients because they do not have to return for 48- or 72-hour scans. Furthermore, they facilitate earlier institution of therapy by decreasing the interval between diagnostic scanning and radioiodine treatment. (Endocr Pract. 1998; 4:11-16)
CD8+CD28- T suppressor cells and the induction of antigen-specific, antigen-presenting cell-mediated suppression of Th reactivity.

Summary: Human CD8+CD28− suppressor T cells (Ts) are a subset of T cells generated in the course of in vitro and in vivo immunizations. Ts recognize MHC class I:peptide complexes and inhibit the reactivity of T helper cells (Th) with cognate antigen specificity. We have demonstrated for the first time that CD8+CD28− Ts represent a unique subset of regulatory cells that induces the differentiation of tolerogenic antigen-presenting cells, initiating a suppressive loop which results in the induction and spreading of Th unresponsiveness.
The length-difficulty relation in serial memorization of words, pictures, and snowflakes

Arrays of 3, 6, 9, or 12 items were studied until they could be ordered from memory without error. A power function described the relation between array size and study time for words, pictures of objects, and pictures of snowflakes. Under two payoff conditions, the exponents for words and snowflakes were around 2.3 and for pictures, 2.0.
A REVISION OF SCHIMPERELLA (BRACHYTHECIACEAE)

Schimperella is a small African genus related toRhynchostegium. It is characterized by noncomplanate plants with erect capsules and reduced endostomes. Two species are recognized:S. katalensis andS. rhynchostegioides. A proposed synonym ofS. rhynchostegioides, Rhynchostegium nervosum, is best placed inIsothecium, asIsothecium nervosum.
Evidence of morphology-specific isozymes in Candida albicans

S-Adenosylmethionine (SAM) synthetase of yeast and hyphal-phase cells of the dimorphic fungusCandida albicans was characterized by kinetic analysis and response to inhibitors. The enzyme from yeast-phase cells has a Km of 0.17 mM for methionine, 0.14 mM for ATP, and is inhibited (in vitro) by dimethyl-sulfoxide, methionine sulfone, and methionine sulfoxide. The hyphal-phase SAM synthetase has a Km of 0.06 mM for methionine, 0.02 mM for ATP, and its activity (in vitro) is enhanced by the substances that inhibit the yeast-phase enzyme. These data strongly suggest that isozymes of SAM synthetase are present inC. albicans and that they are possibly morphology specific. In vivo studies revealed that synthesis of the enzyme is repressed by the addition of methionine to the growth medium and that specific activity of the enzyme increases when intracellular SAM levels are lowered. In addition, it was shown that the increase in specific activity seen during yeast → hypha morphogenesis and in yeast cells grown in a methionine-free medium involves de novo protein synthesis.
Cystathionine γ-synthesis from homocysteine and cysteine by mammalian tissue

Abstract Extracts of human and of rat liver synthesize [ 35 S]cystathionine from homocysteine and [ 35 S]cysteine, the reaction thus taking place by γ-activation of the homocysteine and addition of cysteine. Optimum conditions for the synthesis were established; human liver and rat liver differ in their requirement for cysteine and in pH optimum. Upon fractionation of crude extracts with ammonium sulfate, homocysteine cystathionine-γ-synthase activity paralleled that of cystathionase, with both human and rat liver. In each case the two activities were precipitated by homologous monospecific rabbit anti-cystathionase serum, confirming that the γ-synthase activity is a function of cystathionase. Administration of homocysteine and [ 35 S]cysteine to mice resulted in the production of [ 35 S]cystathionine in liver, kidney, and brain. However, evidence in the literature and unpublished results from this laboratory indicate that administration of cysteine to patients with homocystinuria, who presumably have elevated endogenous tissue concentrations of homocysteine, does not lead to the production of cystathionine, and it is speculated that in man there may be a control mechanism to prevent γ-activation of homocysteine.
Experience with distal bile duct cancers in U.S. Veterans Affairs hospitals: 1987–1991

Background Treatment selection and results were reviewed in a population with distal bile duct cancers. Method Cases of bile duct cancer were retrieved from computerized U.S. Department of Veterans Affairs records from 1987–1991. Result: A total of 156 patients with distal bile duct cancers were recovered (34 resections, 37 operative bypasses, and 85 nonoperative biliary intubations). Mean survival after resection was 22 months, which was significantly higher than after biliary bypass (14 months) or intubation (11 months). Death rate within 30 days of resection, bypass, or intubation was 11%. Distal bile duct cancer had a much higher resectability rate (48%) than did pancreatic cancer (22%) and significantly longer mean survival by stage. Projected 5-year survival rate after resection was 21% for localized cancers, but no 3-year survivors were seen with nodal metastases regardless of treatment. Conclusions Resection increases survival in patients with distal bile duct cancer. Five-year survival was achieved only when patients when nodal or other metastases were absent; most resections do not result in cure and prolonged survival also can occur without resection. J. Surg. Oncol. 64:242–245 © 1997 Wiley-Liss, Inc.
Ma-Brueckner correlation energy.

We point out that the {ital e}{sup 2} dependence of the term in the correlation energy of a high-density electron gas, proportional to the gradient squared of the charge density, was rigorously derived by Ma and Brueckner only for infinitely long-wavelength variations in the charge density. We also correct an error made in obtaining the coefficient of this term which arose because of long-range Coulomb anomalies in the exchange energy which they subtracted from the exchange-correlation energy.
Perceived Hostile Media Bias, Presumed Media Influence, and Opinions About Immigrants and Immigration

This study explores hostile media bias and third-person perceptions of the influence of media coverage of immigrants using data (N = 529) from North Carolina, where the Latino population grew almost 400% in two decades. As hypothesized, anti-immigrant sentiment was significantly related to perceptions of “hostile” (pro-immigrant) news coverage. However, anti-immigrant sentiment was not directly related to belief in coverage effects on others. Analysis revealed two “paths” for relationships among anti-immigrant sentiment, exposure and attention to media coverage, perceived media bias, and presumed media influence or third-person perceptions.
Analysis of tree algorithms for the simulation event list

The simulation event list is a priority queue found in simulation packages like SIMULA. Its task is to hold the pending events of the simulation, so that they can be executed in the correct order. For varying reasons, most standard algorithms are poorly suited to the special demands of this application. Recent work, on the average-case performance of the binary search tree (BST) and p-tree algorithms under these conditions, is presented. The algorithms are shown to be worse than O(log(n)) in many cases.
A novel behavioral model that discriminates between 5-HT2A and 5-HT2C receptor activation.

Abstract 2,5-Dimethoxy-4-iodoamphetamine (DOI), a serotonin (5-HT) 2A/2C receptor agonist, elicits shaking behaviors in rodents, which have been reliably quantified as behavioral correlates of 5-HT 2A receptor activation. Such studies are lacking in the rabbit. As part of our research examining the role of the 5-HT 2 receptor in rabbits, we analyzed the behavioral effects of systemically administered DOI in rabbits. DOI (0.01–3 μmol/kg) or vehicle was injected, and two distinct behaviors, head bobs (vertical head movements) and body shakes (wet dog shakes), were counted for 90 min following the injection. DOI dose-dependently increased the number of head bobs and body shakes. The selective 5-HT 2A receptor antagonist ketanserin (1–3 μmol/kg), 1 h before DOI (0.3 μmol/kg) challenge, significantly attenuated head bobs, but not body shakes. In contrast, the selective 5-HT 2C receptor antagonists SDZ SER 082 (1–3 μmol/kg) and SB 206553 (1 μmol/kg) 30 min before challenge, significantly reduced body shakes but not head bobs produced by the same dose of DOI. This study establishes that, in rabbits, DOI mediates head bobs via 5-HT 2A receptors and body shakes via 5-HT 2C receptors. Thus, the rabbit provides a novel behavioral assay that discriminates between 5-HT 2A and 5-HT 2C receptor activation.
Bounded Linear Stability Analysis - A Time Delay Margin Estimation Approach for Adaptive Control

This paper presents a method for estimating time delay margin for model-reference adaptive control of systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent the conventional model-reference adaptive law by a locally bounded linear approximation within a small time window using the comparison lemma. The locally bounded linear approximation of the combined adaptive system is cast in a form of an input-time-delay differential equation over a small time window. The time delay margin of this system represents a local stability measure and is computed analytically by a matrix measure method, which provides a simple analytical technique for estimating an upper bound of time delay margin. Based on simulation results for a scalar model-reference adaptive control system, both the bounded linear stability method and the matrix measure method are seen to provide a reasonably accurate and yet not too conservative time delay margin estimation.
The effect of temperature on the soot onset chemistry in one-dimensional, atmospheric-pressure, premixed ethylbenzene flames

Abstract This work was conducted to investigate the effects of temperature on soot formation/oxidation chemistry in the vicinity of the soot onset threshold (ϕcritical) in one-dimensional, laminar, atmospheric-pressure premixed ethylbenzene flames. The effects of temperature on the evolution of soot precursors were observed just prior and subsequent to soot onset. Liquid ethylbenzene was prevaporized in nitrogen and blended with an oxygen–nitrogen mixture and, upon ignition, premixed flat flames were stabilized over a burner at atmospheric pressure. Three flames at the same fuel-to-air equivalence ratio ( ϕ = 1.74 ) but with different temperature profiles were obtained by regulating the total heat loss from the flame to the burner, as a result of altering the cold gas velocity of the reacting gases through the burner. A 100-K spread was detected among the three flame temperature profiles. The coolest flame was slightly sooting, the intermediate temperature flame was at the visible onset of sooting, and the hottest flame was not sooting. Combustion products were sampled at various heights in these flames. CO and CO2 mole fractions were found to increase with temperature, supporting the hypothesis that with increasing temperature the rate of oxidation reactions increases faster than the rate of soot formation reactions. Again supporting the same hypothesis, the mole fractions of at least some of the suspected soot precursor hydrocarbons decreased with increasing temperature. Similarly, both the number and the concentrations of detected polycyclic aromatic hydrocarbons (PAH) and oxygenated aromatic hydrocarbons were highest in the slightly sooting, i.e., the coolest flame. This flame also had the highest condensed phase/gaseous phase PAH ratio among the three flames. However, whereas in all three flames the mole fractions of PAH were disparate in the broad neighborhood of the flame zone, they converged to similar values in the postflame zone at 7 mm height from the surface of the burner. Experimentally obtained mole fractions of effluent species were compared with predictions from a detailed kinetic model.
Modification of a simple fractal tree growth scheme: Implications on growth, variation, and evolution

A simple recursive tree growth scheme is modified to include a biological constraint on growth. This two-dimensional model consists of rules for monopodial branching where a new growth may either be a branch or a leaf. The determinants of this new growth are the mass of the tree and the leaf surface area, the ratio of these two parameters being defined as the Tree Ratio. Given initial conditions and a desired Tree Ratio, a tree will “grow”. An analogy is made between the parameters of the model and the genetic makeup of a tree; therefore, one set of parameter values can be viewed as a single species. A small amount of constrained randomness is employed, giving rise to variability within a species. By including leaves and the Tree Ratio criteria, the trees generated with this model are qualitatively more realistic looking than can be obtained with the branching rules alone. In addition, it is shown that two trees, chosen for their similar genetic makeup yet different overall appearance (Ficus elastica and F. benjamina), can be comparatively realized with this model.
Metal hydride batteries research using nanostructured additives

Abstract We describe here, our recent research efforts to improve the capacity of metal hydride batteries using nanostructured additives. Nanostructured additives of palladium, copper and nickel were incorporated separately into the negative electrode of the metal hydride batteries. The nanomaterials were synthesized by template-based methods and characterized by scanning electron microscopy. These nanomaterials were incorporated in the negative electrode of the metal hydride battery and the electrochemical performance at 2 C rate was studied. The nanomaterial-incorporated negative electrodes all showed increased cell voltage and negative electrode potential compared to that of a pristine cell. The increase in discharge capacity for a cut-off voltage of 1 V depends on the nanomaterial incorporated and a comparative analysis of the performance of the different batteries is presented.
Enthalpies of mixing of some aqueous electrolytes at 373.15 K

Abstract The enthalpies of mixing of a variety of aqueous electrolytes at an ionic strength of 1.000 mol·kg−1 have been measured at 373.15 K. The mixtures studied were LiBr + KBr, NaBr + KBr, KBr + (C4H9)4NBr, NaCl + Na2SO4, NaCl + MgCl2, MgSO4 + Na2SO4, MgCl2 + MgSO4, NaCl + MgSO4, and MgCl2 + Na2SO4. In contrast to most previous enthalpies of mixing of alkali halides, the mixtures with multivalent ions studied here often have large temperature dependences. The results for the mixtures involving MgSO4 are consistent with a higher degree of ion pairing as the temperature increases. The present measurements, together with Gibbs energies of mixing at 298.15 K, allow the calculation of Gibbs energies of mixing at the higher temperature. This appears to be the most accurate and convenient method available for determining Gibbs energies of mixing at high temperatures.
Stereoinduction by distortional asymmetry

Steric, torsion, stereoelectronic and polar effects are widely used to explain and predict the stereochemical outcome of synthetic organic reactions. Here, the asymmetric distortion of the reactant is considered and used to explain the observed stereoselectivity where these accepted models are unable to provide a clear prediction.