cssi/SciSciGPT-SciSciNet huggingface dataset:
Diluted magnetic semiconductor superlattices and heterostructures

Abstract Diluted magnetic semiconductors (DMS) are mixed semiconducting crystals whose lattice is made up in part of substitutional magnetic ions. Cd1−xMnxTe and Hg1−xMnxTe are examples of such materials. Their structural and band parameters can be “tuned” by composition over a wide range. They can thus be exploited in situations completely similar to those involving Ga1−xAlxAs. Using molecular beam epitaxy, we have grown Cd1−xMnxTe superlattices with alternating Mn content, having up to 150 layers, with layer thickness ranging from 50 to 100 A. The superlattice structure is clearly revealed by transmission electron microscopy and by zone-folding of the phonon spectrum observed in Raman scattering. Photoluminescence observed on Cd1−xMnxTe superlattices is several orders of magnitude greater than that from a Cd1−xMnxTe film with uniform Mn content, or from bulk Cd1−xMnxTe specimens. The presence of localized magnetic moments in DMS results in a strong exchange interaction between these moments and band electrons. This in turn leads to gigantic Zeeman splittings of impurity states, exciton levels, Landau levels, and the bands themselves. Zeeman splittings as large as 20 meV (which in non-magnetic semiconductors would require unrealistic megagauss fields) are easily achieved in DMS in fields of several kilogauss. Since the magnitude of this exchange-induced splitting in DMS can be comparable to the binding energies and to the minigaps encountered in multiple quantum wells, DMS superlattices hold promise of a host of novel effects of both fundamental and applied interest.
A brief history of testosterone.

Purpose: We explore the history of testosterone in the context of medical and scientific developments.Materials and Methods: A review of the scientific and historical literature was conducted.Results: The origins and effects of testosterone have been recognized throughout the history of humankind. Hunter performed testicular transplantation experiments in 1767 while studying tissue transplantation techniques, and almost a century later Berthold linked the physiological and behavioral changes of castration to a substance secreted by the testes. Brown-Sequard gave birth to the field of organotherapy in 1889 when he announced that his auto-injection of testicular extracts resulted in rejuvenated physical and mental abilities. Steinach and Niehans expanded upon Brown-Sequard's work with rejuvenation treatments involving vasoligation, tissue grafts and cellular injections. In 1935 David et al isolated the critical ingredient in organotherapeutic treatments, testosterone.Conclusions: The effects of the powerful...
The f(q) mock theta function conjecture and partition ranks

In 1944, Freeman Dyson initiated the study of ranks of integer partitions. Here we solve the classical problem of obtaining formulas for N e (n) (resp. N o (n)), the number of partitions of n with even (resp. odd) rank. Thanks to Rademacher’s celebrated formula for the partition function, this problem is equivalent to that of obtaining a formula for the coefficients of the mock theta function f(q), a problem with its own long history dating to Ramanujan’s last letter to Hardy. Little was known about this problem until Dragonette in 1952 obtained asymptotic results. In 1966, G.E. Andrews refined Dragonette’s results, and conjectured an exact formula for the coefficients of f(q). By constructing a weak Maass-Poincare series whose “holomorphic part” is q -1 f(q 24), we prove the Andrews-Dragonette conjecture, and as a consequence obtain the desired formulas for N e (n) and N o (n).
Acylation with diangeloyl groups at C21–22 positions in triterpenoid saponins is essential for cytotoxcity towards tumor cells

Saponins are natural surfactants, found in many plants. Certain saponins are bioactive compounds with anticancer, antivirus and hemolytic activities. The mechanism is unknown. A saponin with antitumor activity was identified in Xanthoceras sorbifolia Bunge (Sapindaceae) and purified. This saponin is a triterpenoid saponin with a trisaccharide chain attached at C3 of the aglycone and two angeloyl groups acylated at C21 and C22. It inhibits the growth of tumor cells with IC50=2 microg/ml in OVCAR3 cells. To study the structure-activity relationship, the diangeloyl group or the carbohydrates of Xanifolia-Y were removed and tested for activity. It was found that removal of both angeloyl groups in C21 and C22 positions completely abolished its activity (IC50>120 microg/ml). However, when carbohydrates were remove, its activity was reduced but was not abolished (IC50=10 microg/ml). These results suggest that a presence of diangeloyl group in the triterpene structure play an essential role for activity. By comparison, compounds with a similar structure as Xanifolia-Y but have only one angeloyl group at C22: Xanifolia-X (IC50=6 microg/ml) or at C21: beta-escin (IC50=10 microg/ml), have less activity. Results suggest that diangeloyl group in both C21 and C22 positions are important contributing activity. Similar results were observed in hemolytic activity. It is concluded that acylation with angeloyl group at C21 and C22 positions of triterpenoid saponin is essential for its activity.
Sulfatide synthesis: inhibition by experimental allergic encephalomyelitis serum.

The rate of 35S incorporation into cerebroside sulfate in cultures of embryo mouse spinal cord shows a rapid acceleration at the time of myelin formation. Exposure of cultures to dilute serum from rabbits with experimental allergic encephalomyelitis results in almost complete inhibition of sulfatide synthesis. Within 24 hours after replacement of inhibiting medium with normal medium there is an increase in sulfatide synthesis followed by myelination.
Further studies on the effect of papaverine upon the cardiotoxic lesions of digitalis in the dog.

Abstract The fact that toxic doses of digitalis may produce myocardial lesions in experimental animals has been emphasized in many publications. 1–3 One of us (F. A. K. 3 ) has recently submitted evidence that aminophylline and theobromine sodium acetate, by virtue of their dilating effect upon the coronary arteries, are more efficient than is papaverine in preventing myocardial lesions induced by toxic doses of digitalis. Since papaveine is known to be a potent coronary dilator, we have been perplexed by these results, and this work is presented to clarify further the previously reported experiment. 3
Relative motions of the Australian, Pacific and Antarctic Plates estimated by the Global Positioning System

GPS measurements spanning ∼3 years have been used to determine velocities for 7 sites on the Australian, Pacific and Antarctic plates. The site velocities agree with both plate model predictions and other space geodetic techniques. We find no evidence for internal deformation of the interior of the Australian plate. Wellington, New Zealand, located in the Australian-Pacific plate boundary zone, moves 20±5 mm/yr west-southwest relative to the Australian plate. Its velocity lies midway between the predicted velocities of the two plates. Relative Euler vectors for the Australia-Antarctica and Pacific-Antarctica plates agree within one standard deviation with the NUVEL-1A predictions.
The Economic Analysis of Large Cross-Section Conductor in ±800kV DC Project

Conductor scheme is one of most key issues in the design of the transmission lines project, and it is significant for the construction cost and safe operation of transmission lines project. It can be aslo concluded from analysis on application of existing conductor that the appropriate decrease of number of bundle conductor and increase of the conductor cross-section will reduce lines loss, which has remarkable social-economic benefits. In this paper, the economic analysis of large cross-section conductor is conducted based on ±800kV DC Project. Some useful suggestions are given.
Technologies for convergence in the metro network

Traditional metro network architectures comprise multiple layers of networking equipment supporting a wide array of services and packet-oriented applications. Among others, these include WDM, SDH, ATM, Ethernet and IP, each requiring its own network elements and associated management solutions to perform its own independent networking functions. While these work well individually, the combined network is cumbersome and inefficient. Recent advancements in network technologies are now changing the way metro networks are designed. Multi-functional consolidation through technology integration and the standardization of protocol inter-networking methods are leading to a converged network solution in support of a diverse set of packet-aware service offerings. This presentation will explore new technologies that are enabling convergence in the metro network, both across layers and across services.
An intelligent simulation environment for production/distribution systems

Abstract Simulation as a powerful tool for analysis and design of systems can be brought directly to the control of the end users by means of intelligent interface systems. This would eliminate the need for hiring the services of simulation analysts and increases the speed of system analysis and design, thereby resulting in more timely information. This article presents a simulation environment for production/distribution domain in which natural language is used as the sole means of representing the system under simulation analysis.
Isolation of a cellular protein that binds to the human immunodeficiency virus Tat protein and can potentiate transactivation of the viral promoter.

Abstract The human immunodeficiency virus type 1 Tat protein is a powerful transactivator of the viral long terminal repeat (LTR). We have identified a cellular protein that strongly binds to Tat and can complement Tat transactivation in rodent cells. The cellular protein of about 36 kDa was isolated from extracts of human cells by Tat peptide-affinity chromatography and can form a complex with Tat in vitro. Tat transactivation is inefficient in rodent cells microinjected or transfected with the reporter plasmid pHIV-LTRCAT plus the Tat-expressing plasmid pCV-1. Remarkably, coinjection of purified 36-kDa protein with pHIV-LTRCAT plus pCV-1 stimulated Tat transactivation 2.7- to 4.9-fold. Taken together, our findings suggest that the 36-kDa protein may be a transcription factor or modulator that is important for efficient Tat transactivation.
Fundamental Theorem of Natural Selection

FISHER1 in 1930 stated his “fundamental theorem of natural selection” in the form: “The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time.” Later, Fisher2 restated his theorem more clearly: “The rate of increase in the average fitness of a population is equal to the genetic variance of fitness of that population”. The “genetic variance” in the foregoing statements is the linear or additive component of the fitness variance in current literature. Fisher obtained his result on the basis of a continuous time model with logarithmic fitness. This communication gives a simple derivation for an appropriate corresponding expression for the discrete-generation model and points out when Fisher's theorem still applies and when it does not.
Autopsias de lo real: resucitando a los muertos

The sense of the real, or the material—the dead body—as an inextricable part of the sacred does not disappear in the secular environment of the nineteenth and twentieth centuries. This article analyzes specific humanitarian narratives centered on the practice of autopsy and mummification, in which the traces of Catholicism act as a kind of spectral discourse of the imagination, where the real is configured in forms of the uncanny, the monstrous or the sacred.
From I-O Economics S-C-P Paradigm Through Strategic Groups to Competence-Based Competition: Reflections on the Puzzle of Competitive Strategy

Over the past 20 years one basic question which has occupied the attention of both researchers and practitioners in the strategic management field is ‘with whom and how do firms compete?’ How research in strategy has attempted to answer this question over the past 20 years is the subject of this article. We begin by reviewing the literatures on industrial organization, spatial competition, strategic groups, cognitive communities and networks and examine how each of these theoretical perspectives have been used to answer basic questions of competition and rivalry. We then show how the resource-based view of the firm and the theory of competence-based competition can be used to integrate these perspectives. We conclude by proposing six issues which should motivate future strategy research, and which can help and enhance our understanding of how firms compete.
Effect of body size and cage profile on the shear strength of bones of caged layers.

Abstract 1. The effects of body size and cage profile on the shear strength of bones from caged layers aged 72 weeks were studied. 2. Bones tested included the radius, ulna, humerus, femur, and tibiotarsus. 3. The ultimate shear force of the femur, tibia, and humerus all increased as body size increased (P<0.01). 4. The wing bones of birds housed in high profile cages had higher shear breaking loads than birds housed in low profile cages. 5. The ultimate shear stresses of the bones were not affected by body size or cage profile. 6. The radius had the highest shear stress (29.2 MPa), followed in descending order by the ulna (19.1 MPa), tibiotarsus, humerus (11.4 MPa) and femur (11.3 MPa).
A novel 3-D mineralized tumor model to study breast cancer bone metastasis.

Background Metastatic bone disease is a frequent cause of morbidity in patients with advanced breast cancer, but the role of the bone mineral hydroxyapatite (HA) in this process remains unclear. We have developed a novel mineralized 3-D tumor model and have employed this culture system to systematically investigate the pro-metastatic role of HA under physiologically relevant conditions in vitro. Methodology/Principal Findings MDA-MB231 breast cancer cells were cultured within non-mineralized or mineralized polymeric scaffolds fabricated by a gas foaming-particulate leaching technique. Tumor cell adhesion, proliferation, and secretion of pro-osteoclastic interleukin-8 (IL-8) was increased in mineralized tumor models as compared to non-mineralized tumor models, and IL-8 secretion was more pronounced for bone-specific MDA-MB231 subpopulations relative to lung-specific breast cancer cells. These differences were pathologically significant as conditioned media collected from mineralized tumor models promoted osteoclastogenesis in an IL-8 dependent manner. Finally, drug testing and signaling studies with transforming growth factor beta (TGFβ) confirmed the clinical relevance of our culture system and revealed that breast cancer cell behavior is broadly affected by HA. Conclusions/Significance Our results indicate that HA promotes features associated with the neoplastic and metastatic growth of breast carcinoma cells in bone and that IL-8 may play an important role in this process. The developed mineralized tumor models may help to reveal the underlying cellular and molecular mechanisms that may ultimately enable more efficacious therapy of patients with advanced breast cancer.
Prenotification, Incentives, and Survey Modality: An Experimental Test of Methods to Increase Survey Response Rates of School Principals

Abstract Teacher and principal surveys are among the most common data collection techniques employed in education research. Yet there is remarkably little research on survey methods in education, or about the most cost-effective way to raise response rates among teachers and principals. In an effort to explore various methods for increasing survey response rates, we randomly assigned 1,177 high school principals in the state of Michigan to 1 of 4 experimental conditions. We varied the mode of survey delivery, the mode in which the prenotification letter was sent, and whether or not a $10 incentive was provided. The results indicate that providing a monetary incentive substantially increased response rates over the no incentive condition and that principals were more likely to respond to a paper-based survey than a web-based one.
Preoperative irradiation of cancer of the rectum.

Roentgen therapy given preoperatively to patients with cancer of the rectum in tumor doses of 1,200 to 1,600 roentgens has materially improved the survival rate of patients who have the poorest prognosis, that is, those with lymph node metastases.
Numerical experiments with the lid driven cavity flow problem

Abstract The centerline velocity profiles obtained from the solution of the two- and three-dimensional representations of the lid driven cavity flow problem are compared for different Reynolds numbers. Two configurations were used in this study: a unit cavity and a cavity with an aspect ratio of 2. The Reynolds numbers ranged from 100 to 5000 for all of the configurations studied. A new method of extending the Jacobi collocation technique called spectral difference is developed in this paper together with a unique computational grid. In addition, an iterative method for solving the pressure problem is also developed. This new numerical method allowed the calculation of three-dimensional Navier-Stokes equations to be performed in computers with very modest computational capabilities such as workstations.
Optimally selected chi square statistics for equivalence testing

In some experiments, the aim is to establish equivalence between treatment groups, rather than to establish greater efficacy of one group over another. Examples are drug bioavailability studies, in which it is desired to exhibit bioequivalence between a new formulation of a drug and the standard formulation, and studies of experimental conditions for biological assays, in which it is desired to exhibit equivalent assay response between fresh and non-fresh specimens. In many cases, the outcome measure is continuous, but the investigator prefers to dichotomize it on the basis of a threshold. If the threshold is selected to make the test statistic most favorable for equivalence, standard chi square percentile points are incorrect. Here, we derive asymptotically correct percentile points and significance levels for two approaches to equivalence testing.
Assessment and epidemiologic issues related to fatigue

At The University of Texas M. D. Anderson Cancer Center, a multidisciplinary workgroup was assembled to review issues, current research, and areas of future research related to the assessment and epidemiology of cancer-related fatigue. Interactive discussion facilitated by a moderator determined the major areas of focus for future research in this arena. The group's ideas were presented to the entire conference following the session. Several gaps in current research related to the assessment and epidemiology of cancer-related fatigue were identified.
Double Cladding Optical Fiber Laser Externally Locked with Guided Mode Resonance Filter

A cladding pumped fiber laser operated in an external cavity configuration is evaluated experimentally using a guided mode resonance filter as the external feedback element.
Ultrasound diagnosis of congenital intrahepatic portosystemic venous shunt

There are few radiologic descriptions of intrahepatic portosystemic venous shunts and all in adults. A case is reported of a newborn where the diagnosis of shunt was made with color Doppler and where the shunt resolved spontaneously at one year of age. Proposed etiologies for intrahepatic portovenous shunts are discussed.
Polarization mode dispersion probability distribution for arbitrary distances.

The probability distribution of the differential group delay (DGD) at any fiber length is determined by use of a physically reasonable model of the fiber birefringence. We show that if the fiber correlation length is of the same order as or larger than the beat length, the DGD distribution approaches a Maxwellian in roughly 30 fiber correlation lengths, corresponding to a couple of kilometers in realistic cases. We also find that the probability distribution function of the polarization dispersion vector at the output of the fiber depends on the angle between it and the local birefringence vector on the Poincare sphere, showing that the DGD remains correlated with the orientation of the local birefringence axes over arbitrarily long distances.
Trading externalities and new equity issues in emerging markets

Abstract The volatility in emerging market finance over the last decade has highlighted the importance of developing equity exchanges to enhance risk sharing between international investors. Debt markets do not allow for as much risk sharing. Theoretically, stock market development involves trading externalities, as the decision by one firm to list provides a positive spillover for other firms considering an initial offering. This theory thus has a clear policy implication in terms of deliberate government action to promote stock market development. This paper tests empirically for the existence of trading externalities in developing countries, and finds evidence of such externalities for Latin American, but not Asian, stock markets.
Effects of ENSO and PDO Events on Seabird Populations as Revealed by Christmas Bird Count Data

--Analysis of Christmas Bird Count (CBC) data for the Honolulu, HI area showed a population which dropped following the strong 1982-1983 ENSO (El Nifio Southern Oscillation) to 4% of its pre-ENSO value for Great Frigatebirds (Fregata minor) and to 35% for Red-footed Boobies (Sula sula). The time for the populations to regain their pre-ENSO values was over a decade. CBC data for the Farallon Islands, CA shows a less striking but still significant decrease in populations of Brandt's Cormorants (Phalacrocorax penicillatus), Pelagic Cormorants (P pelagicus), and Common Murres (Uria aalge) following the 1982-1983 ENSO. Both the Hawaii and Farrallon Islands data exhibit longer term correlations with the Pacific Decadal Oscillation (PDO). Populations are suppressed during the warm phase of the PDO. CBC data for some California and Oregon coastal areas showed some weaker indications of an ENSO effect for the latter three species but little indication of a PDO effect. Received 21January 2000, accepted 20 April 2000.
Evolution of electronic states in GaP 1 − x N x studied by resonant Raman scattering spectroscopy

Two distinct maxima ${E}_{W}$ and ${E}_{W}^{\ensuremath{'}}$ are observed in the resonant Raman scattering profile for the zone-center longitudinal-optical phonon asymmetric linewidth broadening in ${\mathrm{GaP}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}.$ ${E}_{W}$ originates from the X-point conduction-band state perturbed by isolated nitrogen state ${\mathrm{N}}_{X}$ and the nitrogen-nitrogen (NN) pair and cluster states, and ${E}_{W}^{\ensuremath{'}}$ from the effective band-edge states which are comprised of NN pairs and clusters. The study reveals that ${E}_{W}$ remains stationary with increased nitrogen doping whereas ${E}_{W}^{\ensuremath{'}}$ closely follows the absorption edge.
Chemical reactions between atomic oxygen and formic acid on Pt(111)

Abstract We have studied the influence of 0.25 monolayer of atomic oxygen on the interaction between formic acid and the (111) surface of Pt using the techniques of thermal desorption spectroscopy and high resolution electron energy loss spectroscopy. At low coverages of formic acid the reaction proceeds exclusively via unimolecular decomposition of a formate intermediate, as it would also on the clean surface. Atomic oxygen reacts with the hydrogen released to form gaseous water; two distinct desorption states of water are assigned to reactions with the acid and acyl protons. At high coverages of formic acid there is evidence for new pathways other than unimolecular decomposition. These include reaction between formate and hydroxyl to produce CO 2 and H 2 O at temperatures below 200 K and reaction between formate and water to produce dimeric, gaseous HCOOH. The presence of atomic oxygen opens up new reaction pathways for the decomposition of formic acid on Pt(111). All these pathways rely on hydroxyl and formate adspecies and water admolecules as intermediates. At all exposures of formic acid the majority reactions produce desorption states for CO 2 and H 2 O with peak temperatures greater than 200 K. As exposures increase, several additional reactions begin, as evidenced by new desorption states for CO 2 , H 2 O and molecular HCOOH. These new reactions are explained in terms of depletion of oxygen adatoms and increased surface crowding at high coverage. In two of these reactions formate combines with water and hydroxyl adspecies respectively; to our knowledge this is the first report of such reactions occurring in vacuum on a platinum surface, although these species have been posited to interact on a platinum electrode surface [4,5]. These phenomena suggest that a key to mimicking the behavior of an electrode surface in vacuum might involve increasing the surface coverage to a point approaching that existing in an electrochemical cell.
Competition for water in a pecan (Carya illinoensis K. Koch) – cotton (Gossypium hirsutum L.) alley cropping system in the southern United States

Understanding the belowground interactions between trees and crops is critical to successful management of agroforestry systems. In a study of competition for water in an alley cropping system consisting of pecan (Carya illinoensis) and cotton (Gossypium hirsutum) in a sandy loam soil (Rhodic Paleudult) in Jay, Florida, root systems of the two species were separated by trenching to 120 cm depth. A polyethylene barrier was installed in half of the plots. Spatial and temporal variations in soil water content, root distribution and water uptake by both species, and leaf area development and height of cotton were measured. Interspecific competition for water was greater in the non-barrier treatment near tree rows than at the alley center. Competition became evident 3 to 4 weeks after emergence of cotton and increased during the following 7 to 8 weeks. Compared with the non-barrier treatment, the barrier treatment had higher soil water content and better growth of cotton (height, leaf area, and fine root biomass). Cotton lint yield in the barrier treatment (677 kg ha–1) was similar to that in a sole-crop stand, but higher than in the non-barrier (502 kg ha–1) treatment. Lint production efficiency of plants was higher in the interior rows in the non-barrier treatment (0.197 kg lint per square meter of leaf area, compared to 0.117 kg in the barrier treatment). The results suggest that trenching or even deep disking parallel to the tree row may reduce competition for water, but the impact on tree growth cannot be established from this study.
Perception of motion using blur pattern information in the moderate and high-velocity domains of vision

Abstract A series of studies of visual orientation at blurring velocities is integrated and summarized. Surfaces moving rapidly in depth were simulated and sensitivities of observers to depth-related geometric parameters of the resulting blur patterns, such as divergence and curvature, were measured. Examples of some ecological analyses of these parameters as sources of visual orientation information are given. The results indicate that human sensitivity to a number of blur pattern variables is high enough to be useful in guidance of locomotion. It was also found that some of the information about motion contained in blur patterns may actually be form information. It appears that visual motion processig may involve a complex interplay of visual form and motion analysing systems.
Deformation-induced synthesis and structural transformations of metallic multilayers

Abstract At large strains following repeated rolling and folding, stacked foil assemblies evolve into nanometer scale multilayers. The interfacial area per unit volume is a key microstructural metric and together with the interfacial mixing zone scale can be used to gauge alloying and transformation behavior.
CCR2 polymorphisms affect neuropsychological impairment in HIV-1-infected adults

CCR2 is a minor coreceptor for human immune deficiency virus-1 (HIV-1) and its impact on HIV-1-related neuropsychological impairment (NPI) remains unknown. We studied the impact of CCR2-V64I polymorphisms on the development of NPI in 121 HIV-1 patients. The CCR2-64-I allele was associated with rate of progression to NPI when measured from the first study visit (Log Rank p=0.01) or from the estimated time of seroconversion (p=0.02). CCR2-V64I was not associated with plasma or CSF HIV-1 RNA load, suggesting that the impact of CCR2 on neuropathogenesis may involve alterations in inflammatory responses within the CNS rather than a direct impact on viral entry or replication.
The EDE-Q, BULIT-R, and BEDT as self-report measures of binge eating disorder

Binge eating disorder, currently classified as an eating disorder not otherwise specified, is a valid and clinically useful psychiatric diagnosis. Given its probable inclusion in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), identification of self-report measures with high levels of diagnostic utility should improve the likelihood and accuracy of screening. The aim of the current study was to assess the diagnostic utility of two widely used measures of eating disorder symptoms, namely the Eating Disorder Examination-Questionnaire (EDEQ) and the Bulimia Test-Revised (BULIT-R), as well as a factor of the BULIT-R (coined the Binge Eating Disorder Test or BEDT), newly created specifically for the assessment of BED. Participants included 15 individuals with BED and 26 non-BED controls, as determined via the diagnostic section of the Eating Disorder Examination, who met criteria for being overweight or obese. Results showed that the BEDT achieved 100% sensitivity, specificity, positive and negative predictive values. The BULIT-R and Eating Concern subscale of the EDE-Q evidenced strong sensitivity (100 vs 87), specificity (96 vs 100), positive predictive values (94 vs 100), and negative predictive values (100 vs 93), respectively. Results suggest that the BEDT is an excellent overall measure of BED in obese populations. The BULIT-R affords the advantage of ruling out compensatory behaviors, particularly of the non-purging variety (e.g., severe restriction outside of binges), while the brevity of the Eating Concern subscale of the EDE-Q makes it optimal for use in brief screening situations.
Linear mass calibration in the quadrupole ion‐trap mass spectrometer

A new method of operation of the quadrupole ion-trap mass spectrometer in the resonance ejection mode is introduced, that enables one to obtain accurate, linear mass calibration. The method employs linear modulation of the excitation voltage applied to the end-caps while scanning the RF trapping field on the ring electrode. Calibration lines can be defined by a single calibration point because they converge near the reference point where the mass and trapping voltage are equal to zero. Mass assignment accuracy is achieved which is within, or of the order of, errors usually associated with the space-charge effect. The method was implemented on a modified ion-trap detector for ions formed by matrix-assisted laser desorption, but can be used with other ionization techniques and applied to both external and internal calibration routines.
Model System for Liquid Crystal Polymer Blends

Abstract Copolymers which contain 2-hydroxy- 6-naphthoic acid and p-hydroxybenzoic acid, differing only in comonomer ratios, have been used as a model system for blends in which both of the component materials are capable of forming liquid crystalline phases. The rheological behavior suggests that not all of the blends behave the same in the anisotropic melt. Solid state data which was obtained using DSC, DMTA, X-ray, and optical methods is interpreted in terms of miscibility of the component materials. Calculations, based on Windle's sequence matching calculations, have been performed to explain the observed DSC transition temperatures in the blends
Calmodulin localization during capping and receptor-mediated endocytosis

The early response by lymphocytes to challenge with cell surface-directed ligand, such as antibody or concanavalin A (Con A), involves the clustering of initially diffuse ligand–receptor complexes into patches, followed by the gathering of these patches into a cap over one region of the cell and their endocytosis1–3. Using cells of the human lymphoblastoid line WiL2, we have previously shown that receptor-mediated endocytosis occurring at caps involves clathrin-coated vesicles and that the formation of such vesicles is sensitive to drugs such as trifluoperazine dihydrochloride (TFP) that affect calmodulin (CaM), the calcium-dependent regulatory protein of cells3. By indirect immunofluorescence, we demonstrate here that in WiL2, before surface-directed ligand challenge, CaM is distributed diffusely in the cell. On challenge, concurrent with capping of cell-surface receptors for Con A, CaM localization becomes concentrated in regions of the cytoplasm just below the cap. We show that CaM redistribution is sensitive to TFP and dependent on Ca2+ in the external milieu. Capping is mostly unaffected by TFP or removal of external Ca2+. Cytochalasin D (CD), on the other hand, blocks capping completely, but does not prevent the initial redistribution of CaM. These results are consistent with a functional role for CaM in clathrin recruitment to the cell surface beneath ligand–receptor complexes and an initial Ca2+ requiring, microfilament-independent event in receptor-mediated endocytosis.
Examination of millimetre-wave frequency-gain behaviour of GaAs MESFETs

ABSTRACT Analytical expressions are derived for stability factor, maximum stable gain, and maximum available gain for a submicron-gate-length GaAs MESFET. Explicit gain dependence on source inductance, gate transit time and gate-drain feedback capacitance, for example, enables assessment of millimetre-wave device performance possibilities and limitations.
A theory of quantum dynamics of a nanomagnet under excitation

A quantum treatment of magnetization dynamics of a nanomagnet between a thousand and a million spins may be needed as the magnet interacts with quantum control. The advantage of the all-quantum approach over the classical treatment of magnetization is the accounting for the correlation between the magnet and the control agent and the first-principles source of noise. This supplement to the conference talk will concentrate on an overview of the theory with a presentation of the basic ideas which could have wide applications and illustrations with some results. Details of applications to specific models are or will be published elsewhere. A clear concept of the structure of the ground and excited macrospin states as magnetization rotation states and magnons in the Bloch/Dyson sense gives rise to a consistent theory of the magnetization dynamics of a ferromagnet modeled by the Heisenberg Hamiltonian. An example of quantum control is the spin torque transfer, treated here as a sequence of scatterings of each current electron with the localized electrons of the ferromagnet, yields in each encounter a probability distribution of the magnetization recoil state correlated with each outgoing state of the electron. This picture provides a natural Monte Carlo process for simulation of the dynamics in which the probability is determined by quantum mechanics. The computed results of mean motion, noise and damping of the magnetization will be discussed.
Retarded, normal, and superior subjects' attainment of verbal concepts at two levels of inclusiveness.

Summary.-Retarded, normal, and superior Ss were compared on their grouping object-level words by criteria at two levels of inclusiveness. With MA held constant, the groups did not differ in level of concept attainment. With CA held constant, the groups did differ: the superior exceeded the retarded and normal; and the normal exceeded the retarded. The groups did nor respond differentially to rhe two levels of inclusiveness; and so, relationships between the groups remained constam at both levels. Three sets of investigators studied how Ss who differed in intelligence level attained concepts presented through concrete and semi-concrete materials. Retarded and normal groups equated for MA did not differ in level of concept attainment (Martin & Blum, 1961; Johnson & Blake, 1960). Normal and superior groups equated for CA did differ; the superior group attained the higher level (Osler & Fivel, 1961 >. Blake and Williams (in press) studied the groups' use of induction and deduction in attaining concepts presented through verbal materials. Retarded, normal, and superior groups equated for MA did not differ in level of concept attainment. Groups equated for CA did differ; the superior exceeded the normal and retarded while the normal exceeded the retarded. These relationships were cot affected differentially by inductive and deductive methods. For all groups, deduction was most effective while two inductive methods were similarly effective. As Rosenberg (1963 j pointed out, there is a need for additional study of retarded and non-retarded Ss' concept attainment with particular attention to identifying whether the groups' responses are influenced by environmental conditions, or experimental variables, like meaningfulness, distribution of practice, and so on. Consequently, the present study was devoted to further examination of the groups' attainment of concepts presented through verbal materials. The focus was on grouping criteria at two levels of inclusiveness. Level of inclusiveness referred to the number of semantic classes encompassed by the concepts. The essential interest was whether the groups would respond differentially when the language requirements of the task were varied by using concepts which differed in inclusiveness. Specifically, the research objectives for groups 'This study was part of the work performed pursuant to contracts with the Bureau of Research, U. S. Office of Education (Proiect 1356 and Project 5-0250). In addition, the investigators express appreciation for the cooperation and &sismce extended by the staffs and smdents of the Clarke County (Georgia) School Disvicr and the Madison County (Georgia) School District. Jcrry Allen, Marshall Waters, 111, and Joan Bond assisted in completing the project.
Novel applications of lasers in biology, chemistry, and paleontology

Los Alamos National Laboratory has a long history of exploring unconventional applications for lasers. Three novel applications currently under investigation include using lasers for the analysis of dinosaur gastroliths, for detecting Salmonella contamination in chicken eggs, and for ultra- sensitive, ultra-stable interferometry.
Local negotiation with heterogeneous groundwater users

This paper assesses the political implications of intra-aquifer heterogeneity in the benefits and costs of optimal groundwater management. We use simulation modeling to predict groundwater extraction regimes under two alternative local decision-making structures and compare these structures to optimal management. Local collective action performs poorly when the intra-aquifer disparity in the potential gains is large. Moreover, large intra-aquifer disparity is generally associated with large potential gains. As a result, local collective action is unlikely to be successful in capturing the largest welfare gains. Individual subregions within a groundwater basin almost always benefit most from political structures whose outcomes diverge from optimal management. These results may be of particular interest to policymakers in California. The state of California currently allows local regions to make their own decisions about groundwater management with little outside intervention. The analysis in this paper suggests that there may be regions where large potential gains from optimal management are available, but cannot be realized by the two alternative local political institutions. This suggests that there may be a role for State intervention in the local political processes by which local water management decisions are made.
Virtual Visits — Confronting the Challenges of Telemedicine

Telemedicine has the potential to substantially expand access to high-quality health care, overcoming not only geographic but also socioeconomic barriers to care, and to substantially reduce health care costs. But it faces a number of major threats along the way.
Hypoxia and hypercapnia as respiratory stimulants and depressants.

Abstract The effect of wide variations in arterial O2 and CO2 tensions on phrenic nerve activity was evaluated in anesthetized dogs which were paralyzed so that the physical properties of the lung and chest wall could not influence respiratory neuron response. The techniques used allowed the effects of hypoxia and hypercapnia to be assessed either separately or in combination. The results showed that hypoxia enhanced the stimulating effects of hypercapnia on respiratory neuron response by (1) decreasing the arterial CO2 tension at which phasic phrenic activity begins and by (2) increasing the change in phrenic nerve activity produced by a given rise in arterial CO2 tension. However, hypoxia also augmented the depressing effect of hypercapnia by (1) decreasing the arterial CO2 tension at which peak phrenic nerve activity occurred and by (2) reducing the range of arterial CO2 tensions over which progressive hypercapnia increased phrenic nerve activity. The results suggest that the usual steady state methods of evaluating hypoxic response may be measuring opposing effects of hypoxia on ventilation; a stimulating effect of hypoxia at the peripheral chemoreceptor; and a depressing central effect of hypoxia.
Optical Flow, Spatial Orientation, and the Control of Posture in the Elderly

Stabliographic techniques were used to better understand the role of the visual system in the perceptual motor activity of older people as it relates to the maintenance of postural control. The central research question was to determine the sensitivity of the subject's visual system to changes in three standard conditions of optical flow generated by an experimental moving room. Any movement that was present as a function of this optical flow field was recorded on a force platform and expressed in movement of a computed center-of-pressure variable. Movement of the center of pressure was recorded in a baseline condition and in the experimental conditions, and the data were analyzed with respect to differences in the three conditions of optical flow and between both younger and older subjects. The older subject group exhibited less stability than the younger subjects in response to the baseline conditions; and, after adjusting for baseline movement, the center-of-pressure motions of younger and older subjects, in response to the experimental conditions, were compared. No reliable differences were present between younger and older subjects for the radial optical flow condition; in the lamellar flow condition, older subjects moved significantly more than younger subjects; and, in the combined condition (global), the movement of the older subjects was significantly greater than that of the younger subjects for all motion variables recorded. The results are interpreted and discussed both in terms of their implication for falling in the elderly and in the context of an ecological interpretation of the role of vision in maintaining postural stability while both stationary and in motion.
Paired-associate learning with short-term retention: Mathematical analysis and data regarding identification of parameters ☆

Abstract An analysis is given of a simple theory of paired-associate learning in which items may be retained for short intervals before they are learned. Theoretical questions are discussed that involve parameters of the theory, and the problem of identifying these parameters is analyzed. Analyses of several experiments lead to the conclusion that either there is no learning on trials when the presented item is already in short-term memory, or an item usually is learned during the intervals between its presentations. Results of one experiment that permits a choice between these two possibilities favor the assumption that learning occurs mainly during the intervals between an item's presentations. Finally, some statistical methods are presented for the general theory and for the special case that is supported best by the data.
Ultrastructure of pollen exine in centrospermous families

Transmission electron microscopy was utilized to examine pollen walls of selected taxa in theAizoaceae, Amaranthaceae, Basellaceae, Cactaceae, Chenopodiaceae, Didiereaceae, Halophytaceae, Nyctaginaceae, Phytolaccaceae, Portulacaceae, andCaryophyllaceae. This conspectus is an adjunct to scanning electron microscope observations of pollen surfaces and is directed towards elucidating the basic wall structure for these families. Although differences in internal morphology were observed at the inter- and intra-familial levels, they were interpreted as reflecting variations rather than major differences. The data indicate close morphological similarities of the first ten families enumerated above, i.e., those containing betalains. TheCaryophyllaceae, an anthocyanin family, indicated a slightly greater heterogeneity of pollen ultrastructure but not to the extent of disassociating it from the betalain families. In fact, this heterogeneity was rivaled by comparable heterogeneity among and within some of the betalain families. The conclusion is that all families have close pollen morphological relationships.
The Boltzmann equation for (111) valleys in germanium

Abstract A numerical solution is presented for the usual model of electron transport in (111) valleys in n -Ge, with electric fields in the (100) direction. Calculations are for 77°K, with optical and acoustic deformation potential intravalley scattering considered. The effects of acoustic energy loss are quantitatively examined.
Monitoring of rail forces by using acoustic signature inspection

The build-up of internal rail forces causes track failures and these forces, when compressive, can cause track buckling. A technique suitable for field use is required to measure these forces. An acoustic technique based on the dependence of the rail's vibrational response to the magnitude of the axial force in the rail, is proposed here as a method for making such a measurement. A realistic two-layer continuous track model is used to predict the response as a function of the magnitude of the force. Considerations for the design of a system to measure rail forces in the field are discussed.