cssi/SciSciGPT-SciSciNet huggingface dataset:
Time-Optimal, Dual-Stage, Output Transition: With Pre/Post Actuation

Abstract This article considers the output transition problem, to change the output position, from an initial value to a final value, for dual-stage positioning systems. The main contribution of the article is to show that the use of pre- and post-actuation input (applied outside the transition interval without changing the output) can reduce the transition time beyond the standard bang-bang-type inputs from the optimal state-transition approach. An example, motivated by disk-drives application, is used to illustrate the advantages of using (a) pre- and post-actuation and (b) the second actuator in dual-stage positioning system.
Re-probing DNA blots: Wet is better than dry storage of uncharged nylon membranes after removing probes

DNA immobilized on a nylon membrane can be re-probed multiple times with different probes. Protocols typically recommend that DNA blots be stored either dry at room temperature or wet at 4 or −20°C after a probe is removed. This study shows substantial differences in the effect of these storage options on the performance of uncharged nylon membranes in subsequent hybridizations. Uncharged membranes, air-dried and stored at room temperature after probe removal, could not be successfully re-probed. However, excellent rehybridization results were obtained following probe removal when wet membranes were wrapped in plastic and stored at −20°C.
Short-term outcomes and their predictors for patients hospitalized with community-acquired pneumonia.

Abstract Purpose This study of patients who were hospitalized with pneumonia describes 4 short-term outcomes and the relative value of 4 variables for predicting the outcomes. Method We prospectively documented 4 short-term outcomes (hospital length of stay, discharge location, death, 30-day readmission) among 213 adults (mean age = 72.5 years) with pneumonia who were admitted to the hospital. Relationships between the Pneumonia Severity Index (PSI), preadmission walking, malnutrition, grip strength, and outcomes were examined with correlations and multiple logistic regression. Results The mean (SD) hospital stay was 8.8 (10.4) days. Many patients (51.6%) were not discharged to their homes; 13.6% died during admission or within 30 days of discharge. Of 205 patients discharged alive, 23.9% were readmitted within 30 days. All predictor variables correlated significantly with length of stay, discharge, and death. Except for grip strength, all predictor variables correlated significantly with readmission. Regression showed that the PSI contributed significantly to the prediction of all outcomes but that other variables also contributed (R2 = .099 [readmitted] to .484 [discharged to home]). Conclusions Because malnutrition and physical performance measures independently predicted or added to the PSI’s prediction of untoward outcomes, the measures merit inclusion when assessing patients with pneumonia.
Quench induced degradation in Bi2Sr2CaCu2O8+x tape conductors at 4.2 K

With the growing interest in commercial Ag-alloy sheathed Bi2Sr2CaCu2O8+x powder-in-tube conductors (Bi2212) for use in high-field magnets, it is important to understand the quench behavior and limiting criteria of a quench, including conditions that will result in a decrease in critical current. Even though the quench characteristics of low-temperature superconductors NbTi and Nb3Sn are well understood, there is still a lack of data and understanding of what conditions during quenches in high-temperature superconducting (HTS) materials cause degradation of the conductor. In this investigation, quenches are induced in short samples of Bi2212 tape conductors with local heat disturbances using a resistive heater. The voltage and temperature evolution during quenching were recorded and analyzed to determine the normal zone propagation velocity. Furthermore, the quench conditions where varied to identify the threshold quench conditions which result in conductor damage. These conditions are quantified in terms of three parameters: the maximum temperature (Tmax), the maximum rate of temperature increase (dT/dt|max) and the maximum temperature gradient (dT/dx|max). It is found that the normal zone propagation velocity for Bi2212 tape conductor is 20–30 mm s−1. The samples showed high sensitivity during quench, exhibiting large losses in critical current under certain conditions. In all cases the sections of the tape closest to the quench initiation exhibited the highest peak temperatures and loss in critical current. It was found that conductor damage is avoided under the following conditions: dT/dt|max<250 K s−1, dT/dx|max<100 K cm−1 and Tmax<250 K.
String fluid dynamics

We present the general energy - momentum tensor for a dynamical string fluid and show that it predicts that strings are very strong during early cosmological times, weak after the inflationary period, and negligible during the late-time evolution of the universe.
On the periodicity of regular languages

A subclass of regular languages called periodic languages and the corresponding finite automata having nontrivial periodic structure are characterized in this paper. Canonical forms of the regular expressions representing such periodic languages are presented. A systematic procedure to determine the periodicity of any given regular expression is devised through a differential approach. Closure properties of periodic languages are found. Relationships between periodic languages and other subclasses of regular languages, such as finite sets and definite languages, are established. We demonstrate a periodic formation of the grammatical production rules for periodic languages. The reducibility of periodic automata and languages is also studied.
Effect of temperature on the transport of nucleosides into Novikoff rat hepatoma cells growing in suspension culture

Abstract The initial rates of incorporation of uridine and adenosine into the nucleotide pool of Novikoff rat hepatoma cells growing in suspension culture were investigated at 6,16, 26, and 37 ° as a function of the nucleoside concentration in the medium. Below 100 μ m , but not above 100 μ m , the incorporation of either nucleoside followed simple Michaelis-Menten kinetics at all temperatures tested with a K m of about 1 × 10 −5 m , and the V m values decreased with a Q 10 of approximately 1.8 with a decrease in temperature. Above 100 μ m , the rates of incorporation of uridine or adenosine increased linearly with an increase in nucleoside concentration in the medium and the increase in incorporation rates with increase in nucleoside concentration was about the same at all four temperatures. The data are consistent with the conclusion that at low concentrations uridine and adenosine are taken up by the cells mainly by facilitated diffusion or transport, whereas at concentrations above 100 μ m either nucleoside also enters the cells by simple diffusion. The energies of activation for the uridine and adenosine transport reactions were estimated from an Arrhenius plot of the V m values as 8700 and 9200 cal/mole, respectively. Further, the data support the conclusion that at all temperatures tested the transport or diffusion of uridine or adenosine into the cell was the rate-limiting step in their incorporation into the nucleotide pool. At all temperatures, the uridine or adenosine taken up by the cells was rapidly phosphorylated and accumulated in the cell largely as UTP and ATP, respectively.
A Pilot Study for Evaluation of Hypotonia in Children With Neurofibromatosis Type 1

There are currently no objective criteria to evaluate pediatric hypotonia. The purpose of this pilot study was to identify diagnostic criteria for assessing hypotonia in children with neurofibromatosis type 1. Fifty-five subjects between the ages of 1 and 7 years with a diagnosis of neurofibromatosis type 1 were evaluated. A physical therapist recorded a subjective tone assessment and objective tone metrics, including ankle dorsiflexion, knee extension, hip abduction, triceps fat percentage, grip strength, and head lag during a pull-to-sit test. Multivariate logistic regression analysis showed the presence of head lag paired with increased hip range of motion was a significant predictor of hypotonia. The presence of head lag on a pull-to-sit test paired with increased hip range of motion is an accurate predictor of hypotonia in children with neurofibromatosis type 1. These objective measures should be prospectively evaluated in other pediatric populations for their ability to predict hypotonia.
Liability related to peripheral venous and arterial catheterization: a closed claims analysis.

BACKGROUND:Serious complications after peripheral IV and arterial vascular cannulations have been reported. To assess liability associated with these peripheral vascular catheters for anesthesiologists, we reviewed claims in the American Society of Anesthesiologists Closed Claims database.METHODS:Cl
Origins of finite transmission lines for exact representations of transport by the Nernst–Planck equations for each charge carrier

The Barker Brumleve/Buck (BBB) circuits and sub-circuit units, are derived and illustrated for the generation of the conventional two-feature mass transport-controlled impedance. This finite 2-port. 4-terminal network for a single salt system, replaces the classical 1-port, 2-terminal cable transmission line analog because the latter describes only the lower-frequency Warburg feature. Symmetric or asymmetric cell results depend only on the ion or electron terminals used. Three feature impedance plane plots for slow, potential-dependent ion and/or electron transfers with activation resistance and relaxed double layer capacitance, are generated and illustrated. Residual solution resistance and total cell geometric capacitance are included to generate the expected four-feature impedance plots for cells without special features such as ion pairing and adsorption reaction processes. This paper presents new results for a circuit description of electron hopping in redox polymers with concomitant counter ion motion. The forms of single species flux equation: Barker. Nernst-Planck, and electron-hopping are compared. The latter two are converted into responses I or j vs o functions that define T circuit elements. Two forms arise that define the implicit R i or R e , and C i or C e per unit length (i = ion, e = electron), and the corresponding explicit R and C. The analysis uses as examples (1) a single dissolved, inert electrolyte salt M + X + , and (2) a redox polymer electrolyte radical cation and anion, also M + , X + , undergoing second order electron hopping from M to M + . The corresponding forms for the Rs and Cs are derived. A second case is illustrated to show how the d.c. bias changes the polymer cation/anion compositions (assuming Nernstian behavior), and so determines different R e and C e at each composition through the effective second order, concentration-dependent electron hopping.
Implicit delivery options and optimal delivery strategies for financial futures contracts

Abstract Futures contract specification usually allow the short position some variation as to when, where, how much, and what is to be delivered. In this paper we derive the optimal delivery policy for the Treasury Bond futures contracts, and find that our policy produces profits that are positive and statistically significant. This indicates that future prices are ‘too high’ in that the short position can earn profits by skillfully exercising his delivery options. We find the actual delivery policies of market participants depart substantially from the optimal strategy. The implications of these findings for futures traders and bond dealers are discussed.
Nonstationary probability processes, event runs, and the development of patterned response habits

A nonstationary probability process, which included variable runs of homogeneous events, was employed to examine patterning behavior in the unce rtain-ou tcome/binary-decision task. The results showed that specific types of response patterns occurred which appeared to support an assumption that choice behavior was directed by discrete trial reinforcement effects. Further analyses demonstrated that the results were most accurately described by the formation of concepts leading to specific types of response patterning effects.
The effect of stimuli followed by response-independent shock on shock-avoidance behavior.

Four rhesus monkeys were trained on a non-discriminated shock-avoidance schedule (baseline). Stimuli followed by response-independent shock were then presented with the avoidance baseline no longer in effect. The main portion of the experiment consisted of superimposing (independently of responding) the stimuli followed by response-independent shock on the avoidance baseline. Different temporal values of stimulus duration and delay of shock (produced by an avoidance response) were presented successively, using each subject as his own control. When the stimulus duration was short or the delay of shock was long, so that avoidance rate during the stimulus could assume any value without resulting in baseline (avoidable) shocks during the stimulus, a lowered or “suppressed” rate of responding developed during the stimulus. When the stimulus duration was long or the delay of shock was brief, so that avoidable shocks resulted from a response decrement during the stimulus, high or “facilitated” rates of responding developed for a large proportion of the time that the stimulus was present.
Adjacent pore-lining residues within sodium channels identified by paired cysteine mutagenesis

The pores of voltage-gated ion channels are lined by protein loops that determine selectivity and conductance. The relative orientations of these "P" loops remain uncertain, as do the distances between them. Using site-directed mutagenesis, we introduced pairs of cysteines into the P loops of micro1 rat skeletal muscle sodium channels and sought functional evidence of proximity between the substituted residues. Only cysteinyl residues that are in close proximity can form disulfide bonds or metal-chelating sites. The mutant Y401C (domain I) spontaneously formed a disulfide bond when paired with E758C in the P loop of domain II; the same residue, when coupled with G1530C in domain IV, created a high-affinity binding site for Cd2+ ions. The results provide the first specific constraints for intramolecular dimensions of the sodium channel pore.
On the determination of the orientational probability distribution of water in heterogeneous systems from 2H and 17O quadrupolar splittings

Abstract 2 H and 17 O quadrupolar splittings of water in a lyotropic mesophase were found to render ratios widely different from all previous observations. These new results corroborate the interpretation of Halle and Wennerstrom on the determination of the orientational probability distribution of water in heterogeneous systems from 2 H and 17 O NMR.
Does Music Therapy Improve Mental Health in Adults? A Review

The current review provides a summarized synthesis and evaluation of studies addressing the effects of music therapy (MT) alone or MT added to standard care on mental health among adults. Potential studies were identified through electronic bibliographic databases and manual searches. Studies were included for review if (1) the study methodology involved a randomized control trial, (2) the study outcome included a measure of mental health, (3) the study sample included adults ages 18 and older, and (4) the study was published in an English language peer-reviewed journal since 2006. Applying these criteria, the search yielded 593 studies, 9 of which were ultimately retained for review. These studies generally found MT to be more effective than no treatment or than standard care alone. Long-term studies were few, and results suggest no meaningful differences over time.
Spontaneous resolution of a cervical synovial cyst. Case illustration

The natural history of synovial cysts is unpredictable, and some patients experience improvement in their symptoms or stabilization without surgery. The mechanisms behind the formation and resolution of these cysts remain controversial. We report a unique case of complete and spontaneous resolution of a C7‐T1 cervical synovial cyst. A 58-year-old woman presented with persistent tingling and numbness in the medial right forearm and hand, which had lasted for 6 months. She remembered that she had experienced pain in her shoulder and arm after she had engaged in strenuous yard work, but the pain had later subsided. The tingling was located in the medial arm, the forearm, and the medial two fingers. Intermittent neck stiffness and an aching pain in the axilla were present and bothersome. She noted that she had been experiencing difficulty in using her right arm and hand when performing tasks such as opening canned jars, buttoning and unbuttoning, and handling coins. No objective motor, sensory, or reflex alterations were detected. A tentative diagnosis of C-8 nerve root irritation or carpal tunnel syndrome was entertained. Axial T2-weighted magnetic resonance (MR) images revealed a right-sided posterolateral oval epidural lesion measuring 9 6 4 mm. The lesion was contiguous with the facet joint. The MR imaging signal intensity displayed by the lesion approximated that of cerebrospinal fluid (Fig. 1 left [arrow]). A tentative diagnosis of cervical epidural synovial cyst was made and surgery was recommended. For personal reasons, the woman did not wish to submit to surgery for 6 months. At the end of that period, an updated MR imaging study was performed. A review of the images showed that the cyst had entirely disappeared (Fig. 1 right). The patient reported that her symptoms had mostly resolved and surgery was cancelled. Based on the findings on the MR images, the diagnosis of spontaneous resolution of a cervical spinal synovial cyst was made. Contemporary evidence based on experimental and clinical observations suggests that a mechanically stressed joint induces a cascade of events (upregulation and release of angiopoietin-1, interleukins-1 and -6, platelet-derived growth factor, basic fibroblast growth factor, vascular endothelial growth factor, and substance P), 1,5 resulting in synovial hyperplasia, neovascularization, and exudation of fluid (on occasion, hemorrhagic fluid), 3 and culminating in the creation of a cyst. It appears that this process is reversible because the synovial proliferation may regress on withdrawal of mechanical stress. This seems to have happened in our patient, whose curtailment of her previous mechanical activities resulted in spontaneous resolution of the cyst. A review of the recent literature leads us to infer that injection of corticosteroid medications into the facet joint may also have helped reverse this inflammatory cascade. 2
Supervised reinforcement learning using behavior models

We introduce a supervised reinforcement learning (SRL) architecture for robot control problems with high dimensional state spaces. Based on such architecture two new SRL algorithms are proposed. In our algorithms, a behavior model learned from examples is used to dynamically reduce the set of actions available from each state during the early reinforcement learning (RL) process. The creation of such subsets of actions leads the agent to exploit relevant parts of the action space, avoiding the selection of irrelevant actions. Once the agent has exploited the information provided by the behavior model, it keeps improving its value function without any help, by selecting the next actions to be performed from the complete action space. Our experimental work shows clearly how this approach can dramatically speed up the learning process.
Regulation of lymphoid homeostasis by interleukin-15

Interleukin (IL)-15 is a member of the common gamma chain family of cytokines, and is closely related to IL-2. While these two cytokines share several important biological functions in vitro, recent mouse models have demonstrated unique roles for these two cytokines in supporting lymphoid homeostasis in vivo. IL-15 has been shown to regulate the homeostasis of both innate and adaptive immune cells, and this review will discuss several ways in which this pleiotropic cytokine may support lymphoid homeostasis.
Distance-Dependent Enhanced ENDOR Phase (DEEP) Spectroscopy and Its Application to Determination of Solvation Structure around Paramagnetic Ions in Disordered Solids: The Three Ordered Hydration Shells of Aquated Transition Ions

We present a method that improves the spectral resolution and extends the distance range for detection of ordered solvent molecules surrounding a paramagnetic ion in frozen solutions using 1H electron−nuclear double-resonance (ENDOR) spectroscopy. This method is based on the R-3 distance dependence of the proton−electron spin hyperfine interaction and its effect on the electron−nuclear cross relaxation rate. This relaxation effect dramatically influences the ENDOR phase spectrum and appears through the radio-frequency (rf) phase angle dependence (using the conventional rf modulation detection scheme), and thus it is termed distance-dependent enhanced ENDOR phase (DEEP) spectroscopy. Applying DEEP spectroscopy to the conventional CW-ENDOR experiment, one is able to eliminate the large proton matrix peak from disordered solvent molecules. We observe a 4-fold increase in spectral resolution with DEEP spectroscopy for distant protons. When applied to solvation of aquo Mn(II) ions, we resolve 1H hyperfine coup...
Enhanced trophic factor secretion by mesenchymal stem/stromal cells with Glycine-Histidine-Lysine (GHK)-modified alginate hydrogels

Recombinant proteins and cytokines are under broad preclinical and clinical investigation to promote angiogenesis, but their success is limited by ineffective delivery, lack of long-term stability and excessive cost. Mesenchymal stem/stromal cells (MSC) secrete bioactive trophic factors, and thus, may provide an effective alternative to address these challenges. Glycine-Histidine-Lysine (GHK) is a peptide fragment of osteonectin, a matricellular protein with reported proangiogenic potential. We examined the capacity of GHK to up-regulate secretion of proangiogenic factors from human MSC in culture and when covalently coupled to alginate hydrogels. GHK had no apparent cytotoxic effects on MSC in culture over a wide range of concentrations. We detected a dose-dependent increase in vascular endothelial growth factor (VEGF) concentration in media conditioned by GHK-treated MSC, which increased endothelial cell proliferation, migration and tubule formation. We covalently coupled GHK to alginate using carbodiimide chemistry, and human MSC were entrapped in alginate hydrogels to assess VEGF secretion. Similar to monolayer culture, MSC responded to GHK-modified gels by secreting increased concentrations of VEGF and basic fibroblast growth factor compared to unmodified gels. The pre-treatment of MSC with antibodies to α6 and β1 integrins prior to entrapment in GHK-modified gels abrogated VEGF secretion, suggesting that the proangiogenic response of MSC was integrin-mediated. These data demonstrate that the proangiogenic potential of MSC can be significantly increased by the presentation of GHK with a biodegradable carrier, therefore increasing their clinical potential when used for tissue repair.
Increased sensitivity to benzodiazepine antagonists in rats following chronic treatment with a low dose of diazepam.

The effects of benzodiazepine (BZ) antagonists on operant behavior were examined in rats chronically administered a low dose of diazepam (DZ). The low maintenance dose of DZ (5 mg/kg twice daily) was selected as more closely associated with its anxiolytic effects than the higher treatment doses previously used to study BZ dependence. Food-restricted rats were trained to press a lever for food reinforcement under a FR20 schedule of reinforcement prior to the start of DZ administration. Acute administration of DZ caused a dose-dependent reduction of response rates, with 5 mg/kg causing a 50% decrease. Rats treated chronically with DZ became tolerant to its rate-suppressant effects as shown by a 5-fold increase in the dose of DZ required to reduce FR20 response rates by 50%. The BZ antagonist flumazenil (formerly Ro 15-1788; 10–56 mg/kg) suppressed rates of responding in rats treated chronically with DZ. The suppression of operant responding was obtained when flumazenil was given up to 3 h, but not 18 h, after the last treatment with DZ. In contrast, only the highest dose of flumazenil (56 mg/kg) caused reductions of operant responding when given to rats treated with saline. The BZ antagonist CGS 8216 (3.3–33 mg/kg IP), given 10 min prior to the session, was similarly more potent and effective at suppressing operant responding in rats treated chronically with DZ than saline. This procedure may provide a model for the clinical problem of physical dependence to chronically-administered low, anxiolytic doses of BZ tranquilizers.
Semiconductor analysis using finite elements: part II: IGFET and BJT case studies

Semiconductor-like Applications of Finite Elements (SAFE), a novel, nonlinear, general-purpose two-dimensional finite-element code, is applied to problems in device modeling. Case studies of contemporary insulated gate field effect transistor (IGFET) and bipolar junction transistor (BJT) structures are given which demonstrate the reliability, versatility, and efficiency of finite-element methods in general and of the SAFE program in particular. The user-defined SAFE physical model is compared with experiments on a doubly implanted short-channel IGFET. Computer experiments are performed, indicating how to select the type, distribution, and numerical-integration method of finite elements for maximally efficient, assured-convergence, engineering-accuracy analysis, either steady state or transient.
Chronic ischemic heart disease: From concept to fact

Abstract The development and refinement of techniques relating the determinants of increased myocardial oxygen demand to primary or secondary manifestations of inadequate myocardial blood flow made possible certain major advances in the management of chronic ischemic heart disease over the past 25 years. These include objective and quantitative evaluation of the anatomic basis and the functional consequences of ischemic heart disease, risk stratification for patient subgroups and documentation of the effects of therapy. In addition, studies in which ischemic manifestations were shown to be dissociated from increased myocardial oxygen demand have redirected attention to the supply component of the supply to demand balance for myocardial oxygenation. Diagnostic techniques, management schemata and therapeutic evaluation methods for the electrophysiologic alterations of ischemic heart disease have matured more slowly than those for the ischemic manifestations. While the pathophysiologic concepts underlying knowledge of the ischemic manifestations of coronary artery disease were formulated 25 years ago, in the case of arrhythmias, new concepts needed to be developed to provide the direction for technologic and therapeutic advances. Although the patients at risk for serious arrhythmias and sudden cardiac events are known to be those with severe coronary artery disease, impaired left ventricular function and preexisting electrical instability as manifested by frequent and complex ventricular arrhythmias, the sensitivity and specificity for any single factor as a predictor of risk remain to be established. Similarly, methods to predict efficacy of therapy are still under development. Progress will accelerate when specific factors that predict risk are identified and the methods for measuring those factors are developed and applied to the patient in an organized and systematic manner. The thesis underlying this broad conceptional review is that the fostering of the full-time clinical investigator that occurred during the 1960s and the first half of the 1970s and the consequent systematic development and application of quantitative methods to the study of disease in human beings were major forces for the remarkable progress that has been made in the management of all aspects of cardiovascular disease.
Temperature and sample dependence of the binding free energies of complexes in crystals: The case of acceptor-oxygen complexes in Si

The binding free energy ${E}_{\mathrm{b}}$ of a complex ${A,B}$ in a crystal varies not only with temperature but also the concentrations of the constituent species $A$ and $B$ in the sample. Except at very low temperatures, ${E}_{\mathrm{b}}(T)$ is a linear function of $T$ with a slope determined by the configurational entropy and free energy terms. This is quantitatively illustrated for acceptor-oxygen complexes in Si. First principles calculations establish their structures, vibrational spectra, binding energies at $T=0\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, and electrical activities. The temperature-dependence is obtained from (Helmholtz) vibrational free energies and configurational entropies. ${E}_{\mathrm{b}}$ varies much more with temperature for complexes involving species that are present in low concentrations than in high concentrations. The implications of these predictions are discussed.
Altered long-term synaptic plasticity and kainate-induced Ca2+ transients in the substantia gelatinosa neurons in GLUK6-deficient mice

Abstract Functional kainate receptors are expressed in the spinal cord substantia gelatinosa region, and their activation contributes to bi-directional regulation of excitatory synaptic transmission at primary afferent synapses with spinal cord substantia gelatinosa neurons. However, no study has reported a role(s) for kainate receptor subtypes in long-term synaptic plasticity phenomena in this region. Using gene-targeted mice lacking glutamate receptor 5 (GLUK5) or GLUK6 subunit, we here show that GLUK6 subunit, but not GLUK5 subunit, is involved in the induction of long-term potentiation of excitatory postsynaptic potentials, evoked by two different protocols: (1) high-frequency primary afferent stimulation (100 Hz, 3 s) and (2) low-frequency spike-timing stimulation (1 Hz, 200 pulses). In addition, GLUK6 subunit plays an important role in the expression of kainate-induced Ca2+ transients in the substantia gelatinosa. On the other hand, genetic deletion of GLUK5 or GLUK6 subunit does not prevent the induction of long-term depression. These results indicate that unique expression of kainate receptors subunits is important in regulating spinal synaptic plasticity and thereby processing of sensory information, including pain.
Three orbital model for the iron-based superconductors

The theoretical need to study the properties of the Fe-based high-${T}_{c}$ superconductors using reliable many-body techniques has highlighted the importance of determining what is the minimum number of orbital degrees of freedom that will capture the physics of these materials. While the shape of the Fermi surface (FS) obtained with the local-density approximation (LDA) can be reproduced by a two-orbital model, it has been argued that the bands that cross the chemical potential result from the strong hybridization of three of the $\text{Fe}\text{ }3d$ orbitals. For this reason, a three orbital Hamiltonian for LaOFeAs obtained with the Slater-Koster formalism by considering the hybridization of the $\text{As}\text{ }p$ orbitals with the $\text{Fe}\text{ }{d}_{xz}$, ${d}_{yz}$, and ${d}_{xy}$ orbitals is discussed here. This model reproduces qualitatively the FS shape and orbital composition obtained by LDA calculations for undoped LaOFeAs when four electrons per Fe are considered. Within a mean-field approximation, its magnetic and orbital properties in the undoped case are here described for intermediate values of $J/U$. Increasing the Coulomb repulsion $U$ at zero temperature, four different regimes are obtained: (1) paramagnetic, (2) magnetic $(\ensuremath{\pi},0)$ spin order, (3) the same $(\ensuremath{\pi},0)$ spin order but now including orbital order, and finally (4) a magnetic and orbital ordered insulator. The spin-singlet pairing operators allowed by the lattice and orbital symmetries are also constructed. It is found that for pairs of electrons involving up to diagonal nearest-neighbors sites, the only fully gapped and purely intraband spin-singlet pairing operator is given by $\ensuremath{\Delta}(\mathbf{k})=f(\mathbf{k}){\ensuremath{\sum}}_{\ensuremath{\alpha}}{d}_{\mathbf{k},\ensuremath{\alpha},\ensuremath{\uparrow}}{d}_{\ensuremath{-}\mathbf{k},\ensuremath{\alpha},\ensuremath{\downarrow}}$ with $f(\mathbf{k})=1$ or $\text{cos}\text{ }{k}_{x}\text{ }\text{cos}\text{ }{k}_{y}$ which would arise only if the electrons in all different orbitals couple with equal strength to the source of pairing.
Hypointense signal lesions of the articular cartilage: a review of current concepts

Discussion of articular cartilage disease detection by MRI usually focuses on the presence of bright signal on T2-weighted sequences, such as in Grade 1 chondromalacia and cartilage fissures containing fluid. Less emphasis has been placed on how cartilage disease may be manifested by dark signal on T2-weighted sequences. The appearance of the recently described "cartilage black line sign" of the femoral trochlea highlights these lesions and further raises the question of their etiology. We illustrate various hypointense signal lesions that are not restricted to the femoral trochlea of the knee joint and discuss the possible etiologies for these lesions.
Superconducting fluctuations in Bi2Sr2Ca1‐xDyxCu2O8+δ as seen by terahertz spectroscopy

More than one hundred years ago Paul Drude derived the frequency-dependent conductivity σ(o) of a gas of point charges, showing that the width of the spectrum was related to the scattering rate of carriers. Seventy five years later, in the late 1970's and early 1980's, it was recognized that σ(o) of a two-dimensional superconductor above it's transition temperature Tc could be described by the Drude response of interpenetrating gases of electrons and vortices. Here we describe measurements of σ(o) in the high-Tc superconductor system Bi2Sr2Ca1-xDyxCu2O8+δ (BSCCO) using time-domain THz spectroscopy that provide evidence for vortices above Tc. We compare this evidence with results obtained by other probes of fluctuations in cuprate superconductors.
Effects of applied field inhomogeneities on the magnetization reversal of elongated /spl gamma/-Fe/sub 2/O/sub 3/ particles

A detailed micromagnetic study of the effects of nonuniform applied fields in elongated particles is given. As a representative case the magnetization reversal is studied in the presence of a recording head field. The investigation is restricted to an important subproblem: the single particle in an inhomogeneous applied field. This case is also interesting with regard to the development of ultrahigh-density recording systems. Reversible and irreversible magnetization processes are computed for the limit of small and large exchange coupling. Results are presented for both longitudinal and perpendicular media. >
Crises and liquidity : evidence and interpretation

In a large panel of countries, we find that less liquid countries are more likely to default on their external debt. Specifically, for given total external debt, the probability of a crisis is increasing in the proportion of short-term debt and of debt service due and decreasing in foreign exchange reserves. This correlation, however, is consistent with a standard model of optimal default and need not be ascribed to self-fulfilling creditor runs. Also, the correlation with short-term debt appears to be driven by joint endogeneity. The policy implications are discussed.
Association of trxG and PcG proteins with the bxd maintenance element depends on transcriptional activity.

Polycomb group (PcG) and trithorax group (trxG) proteins act in an epigenetic fashion to maintain active and repressive states of expression of the Hox and other target genes by altering their chromatin structure. Genetically, mutations in trxG and PcG genes can antagonize each other’s function, whereas mutations of genes within each group have synergistic effects. Here, we show in Drosophila that multiple trxG and PcG proteins act through the same or juxtaposed sequences in the maintenance element (ME) of the homeotic gene Ultrabithorax. Surprisingly, trxG or PcG proteins, but not both, associate in vivo in any one cell in a salivary gland with the ME of an activated or repressed Ultrabithorax transgene, respectively. Among several trxG and PcG proteins, only Ash1 and Asx require Trithorax in order to bind to their target genes. Together, our data argue that at the single-cell level, association of repressors and activators correlates with gene silencing and activation, respectively. There is, however, no overall synergism or antagonism between and within the trxG and PcG proteins and, instead, only subsets of trxG proteins act synergistically.
Lymphomas or leukemia presenting as ovarian tumors. An analysis of 42 cases

Forty cases of ovarian lymphoma and two of extramedullary leukemia were examined with emphasis on histologic types correlated with age, modes of presentation, operative findings, including frequency of bilaterality and omental spread, clinical course following therapy, and problems in differential diagnosis. Although most cases were referred with diagnoses other than lymphoma (granulosa cell tumor or dysgerminoma, occasionally anaplastic tumor, Krukenberg tumor, or metastatic breast carcinoma), utilization of sections cut at 4 p and stained with hematoxylin and eosin, or sections stained by the methyl green pyronine (MGP), naphthol-ASD esterase (NASL)) or periodic acid-Schiff (PAS) methods helped bring out the lymphoid or hematopoietic nature of the cells. Sixteen patients were under 20 years of age. They had small noncleaved cell lymphoma (undifferentiated Burkitt's and non-Hurkitt's, 10 cases), diffuse immunoblastic large cell lymphoma (4 cases), or acute granulocytic leukemia (2 cases). Twenty-six patients were 29 to 74 years of age and had diffuse large cell lymphoma (10 cases), diffuse immunoblastic large cell lymphoma (9 cases), follicular (nodular) lymphoma (6 cases) or small noncleaved cell lymphoma (I case). Pain with an abdominal or pelvic mass was the most common presentation. Nine tumors were discovered during investigation of other gynecologic complaints. At Iaparotomy, the tumors in 55% of cases involved both ovaries, and in 64% also involved extragonadal sites (usually omentum, fallopian tubes, or lymph nodes). Seventeen patients had tumor affecting one ovary, seven of these without any evidence of extragonadal spread. Forty-two percent (15) of 37 patients with follow-up were alive after 2 years. Only nine patients survived more than 5 years; two subsequently died of lymphoma. Favorable prognostic features included: (I) FIG0 stage I& (2) unilateral ovarian involvement; (3) focal involvement of one ovary; and (4) follicular (nodular) lymphoma. Cancer 52:1933-1943, 1983. YMPHOMAS presenting as ovarian tumors are rare. L Most articles have been individual case reports,'-3 and rare articles have contained a serie~.~.~ Although a few individuals have had prolonged survival after surgery only, it is generally accepted that most patients probably have nodal lymphoma, which has not been detected by available clinical methods, but which has presented in an unusual fashion. This article describes 42 women with extramedullary leukemia or non-Hodgkin's lymphoma in which an ovarian mass was a precursor of the onset
A comparative study of three switching patterns used in S V-PWM control of a matrix converter

AC-AC power converters are becoming essential in most of modern power systems and industrial applications. This conversion is usually done using a traditional converter which consists of a rectifier and an inverter separated by a storage component. During the last two decades, matrix converters gained the researchers attention as an alternative to traditional converters thanks to the advantages they offer. In fact, the absence of the storage component makes the converter more compact and more reliable; two advantages highly required in renewable energy applications such as wind generating systems. Furthermore, the matrix converter provides sinusoidal input and output waveforms, with minimal higher order harmonics; it has inherent bi-directional energy flow capability and operates with unity power factor. In this paper, different modulation techniques of matrix converters are presented with a special interest in the Space Vector Pulse Width Modulation (SV-PWM) that is studied in detail and simulated using Matlab/Simulink. Three different switching sequences are simulated and results are compared in terms of number of commutation per modulation period and total harmonic distortion (TDH) improvements.
Low-level laser treatment accelerated hair regrowth in a rat model of chemotherapy-induced alopecia (CIA)

Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects of antineoplastic chemotherapy for which there is no effective interventional approach. A low-level laser (LLL) device, the HairMax LaserComb®, has been cleared by the FDA to treat androgenetic alopecia. Its effects may be extended to other settings; we have demonstrated that LaserComb treatment induced hair regrowth in a mouse model for alopecia areata. In the current study, we tested whether LLL treatment could promote hair regrowth in a rat model for CIA. Chemotherapy agents cyclophosphamide, etoposide, or a combination of cyclophosphamide and doxorubicin were administered in young rats to induce alopecia, with or without LLL treatment. As expected, 7–10 days later, all the rats developed full body alopecia. However, rats receiving laser treatment regrew hair 5 days earlier than rats receiving chemotherapy alone or sham laser treatment (with the laser turned off). The accelerated hair regrowth in laser-treated rats was confirmed by histology. In addition, LLL treatment did not provide local protection to subcutaneously injected Shay chloroleukemic cells. Taken together, our results demonstrated that LLL treatment significantly accelerated hair regrowth after CIA without compromising the efficacy of chemotherapy in our rat model. Our results suggest that LLL should be explored for the treatment of CIA in clinical trials because LLL devices for home use (such as the HairMax LaserComb®) provide a user-friendly and noninvasive approach that could be translated to increased patient compliance and improved efficacy.
Spatial correlation of atomic electrons: He

Abstract For any two-electron wavefunction whose angular dependence is given in terms of the spherical harmonics of the individual electrons and/or o 12 , where o 12 is the interelectronic angle. a transformation is generated which reduces |ψ( r 1 , r 2 , o 2 , o 1 , o 12 )| 2 to |ψ( r 1 , r 2 , o 12 )| 2 . Geometric aspects of electron correlation are analyzed in terms of this resulting three-coordinate function, with specific application to a number of wave functions for doubly-excited helium. Angular correlation has been studied by integrating |ψ( r 1 , r 2 , o 12 )| 2 over its radial dependence to yield p ( o 12 ), the probability density function for the interelectronic angle. Trends of p ( o 12 ) for doubly-excited states of the helium atom are related to a number of quantities including energies and autoionization widths. These trends can be rationalized in terms of a simple classical model. The full spatial correlation involving |ψ( r 1 , r 2 , o 12 )| 2 is explored by the use of three-dimensional graphs for some of these states.
High frequency simulation of resonant tunneling diodes

The small and large-signal response of the resonant tunneling diode at high-frequencies is studied using a quantum simulator. The Poisson and Schrodinger equations are solved self-consistently for each harmonic using the harmonic balance technique. This ensures that the total current, consisting of the displacement plus conduction currents, is conserved across the device for each harmonic. The RTD exhibits an increased capacitance in the negative differential conductance (NDC) region in agreement with experimental data. As recently proposed this capacitance increase results from the formation of an emitter well capacitor when the well discharges. The derivation of the RTD capacitance from a quasi-static analysis using the differential variation of the de charge in the RTD is shown to be not applicable because the RTD well charges through the cathode but discharges through the anode. The frequency dependence of the conductance and susceptance is similar to reported experimental data. A large frequency dependence of the admittance is only observed when the RTD is biased in the negative differential conductance (NDC) region. These calculations predict an effective reduction of the RTD conductance and capacitance at high-frequency in the NDC region. This effect can be modeled using a quantum inductance in series with the negative resistance of the RTD as recently proposed. Due to the simultaneous reduction of both the conductance and the capacitance at high-frequency in the NDC region the maximum frequency of oscillation does not differ much from its estimate using the low frequency conductance and capacitance. The large-signal response at high-frequency of an RTD biased in the negative differential region is also presented in this paper. The large-signal negative-conductance is shown to decrease with both increasing frequency and ac voltage. >
Cluff E. Hopla (1917–2008)

The Entomological Society of America (ESA) and the field of medical entomology lost an icon in research on zoonotic diseases with the passing of Dr. Cluff E. Hopla. Cluff became a member of ESA in 1951, was Chair of the former Section D, was Program Chair for the 1968 annual meeting, and was elected as a Fellow of the ESA in 1988. He served as co-editor of the Journal of Medical Entomology ( JME ) during the critical 1988–1992 period, shortly after ESA acquired the JME from the Bernice P. Bishop Museum. His dedicated service, editorial insight, and stature in the field helped to expand circulation and content, and secure JME ’s future as the flagship journal of our profession. Cluff joins Moyra, his wife of 56 yr, and is survived by his daughter (Dr. Anna Hopla), his two sons (Dr. Daniel Hopla and Dr. Rick Hopla), and two grandsons (Michael Hopla and Alistair Wilton). Cluff was born in …
Supplemental oxygen and exercise performance in patients with cystic fibrosis with severe pulmonary disease

Patients with cystic fibrosis (CF) and advanced pulmonary disease have pulmonary limitation of exercise, often associated with arterial oxygen desaturation. Improving oxygenation during exercise by providing supplemental oxygen may improve exercise performance in these patients. To test this, we performed graded exercise stress tests in 22 CF patients with severe pulmonary disease (mean PaO2, 64 +/- 2 mm Hg [+/- SE]; PaCO2 46 +/- 2 mm Hg; RV/TLC, 57 +/- 4 percent; FEV1, 38 +/- 4 percent of predicted; FEF25-75%, 13 +/- 2 percent of predicted; median age, 26 years) and compared them to 21 controls (RV/TLC, 27 +/- 4 percent; FEV1, 112 +/- 2 percent of predicted; FEF25-75%, 80 +/- 4 percent of predicted; median age, 29 years). Each subject performed graded exercise stress tests while breathing FIO2 of 0.21 and FIO2 of 0.30. Subjects were blinded to the composition of the inspired gas, and the order of testing was randomized. We found that CF subjects exercised longer, had a higher maximal VO2, higher O2 pulse, and less arterial oxygen desaturation when receiving supplemental O2. Control subjects exercised longer when breathing supplemental O2 but had no significant change in maximal VO2, O2 pulse, or SaO2. Both CF and control subjects had increased end-tidal PCO2 when exercising while breathing supplemental O2. We conclude that CF patients with advanced pulmonary disease have increased exercise tolerance and aerobic capacity when exercising while breathing supplemental O2.