cssi/SciSciGPT-SciSciNet huggingface dataset:
Multiserver Loss Systems with Subscribers

We study a multiserver loss system with two kinds of customers: subscribers and infrequent users. We model the infrequent users' requests for service by a Poisson process. However, noting that the Poisson process is unable to capture repeated interactions as well as retrials, we propose a Markovian on-off-hold model for the subscribers' requests for service that takes into account retrials by subscribers denied service. We analyze this system in an asymptotic regime where the number of subscribers and the arrival rate of the Poisson stream, and consequently the number of servers, grow without bound. In this regime, we identify and prove convergence to diffusion limits for the system. We also prove the convergence of the invariant distributions to the invariant distribution of the limiting diffusions.
Indium Tin Oxide Plasma Frequency Dependence on Sheet Resistance and Surface Adlayers Determined by Reflectance FTIR Spectroscopy

Variable angle reflectance FTIR spectroscopy was used to investigate the optical properties of indium tin oxide (ITO) and fluorine-doped tin oxide (SFO) thin films in the near-IR spectral region. T...
Physical Activity and Health: Dose-Response Issues

The depth of our current knowledge of the dose-response gradient for physical activity and health is highly variable across the different health parameters. To the extent that the existing literature allows conclusions, it appears that (a) most health parameters are related to the amount of habitual physical activity in a graded fashion; (b) intensity of physical activity may be independently related, in a graded fashion, to some health parameters but unrelated to others; and (c) for some variables, the dose-response relationship is linear but, in other cases, is curvilinear. At present, these conclusions must be considered tentative, and most experts agree that further elucidation of dose-response relationships should be a major thrust of future research on physical activity and health.
Erratum to: Adrenal steroid hormones and ethanol self-administration in male rhesus macaques

The units in several figure legends were incorrect in the original publication. Here are the corrections: In Fig 2. Aldosterone (ng/ml) should read “Aldosterone (pg/ml)”. In Fig 4. Aldosterone (ng/ml) should read “Aldosterone (pg/ml)”. In Fig 5. Baseline aldosterone (ng/ml) should read “Baseline aldosterone (pg/ml)”. In Fig 6. 12-month aldosterone (ng/ml) should read “12-month aldosterone (pg/ml)”.
General edge element approach to lossy and dispersive structures in anisotropic media

A new functional for general anisotropic 2½D guided-wave structures is derived, based on a rigorous 3D analysis. An impedance boundary condition at the interface between the anisotropic material and the imperfect conducting ground plane is proposed. The computation domain includes the cross-section of the lossy conducting line where the size of the cross-section has the same order as the skin depth, and the standard impedance boundary condition is no longer held. The vector element analysis procedure, and the subspace iteration method, are then used to find the partial or total system modes. Numerical examples of anisotropic dielectric image waveguide, PFEE bilateral fin line, and two coupled asymmetrical dual lossy transmission lines with finite conductivity and finite thickness are presented. Good agreement with previous publications is observed.
Toward real-time spectral imaging for chemical detection with a digital micromirror device-based programmable spectral filter

Hyperspectral imaging sensors have proven to be powerful tools for highly selective and sensitive chemical detection applications, but they have significant operational drawbacks including slow line-scanning acquisition, large data volume of the resulting images, and a detection time lag due to the computational overhead of the matched-filter analysis. We have recently developed and demonstrated a high-speed, high-resolution, programmable spectral filter based on the Texas Instruments DLP® digital micromirror device (DMD) that is capable of performing matched-filter image processing across a two-dimensional (2-D) field-of-view directly in the optical hardware and will enable real-time chemical detection without slow scanning, large data volumes or expensive postprocessing requirements. Based on traditional optical techniques, our spectral filter encodes the spectral information orthogonal to the spatial image information, enabling the DMD to encode matched-filter information into the spectral content of the scene without disturbing the underlying 2-D image. With this new technology, everything from simple multiband filters to very complicated hyperspectral matched filters can be implemented directly in the optical train of the sensor, producing an image highlighting a target signature within a spectrally cluttered scene in real time without further processing. We will first describe the implementation of a DMD as a multiplexing spectral selector for a 2-D field-of-view, discuss its utility as a multiband spectral filter, and show how the DLP’s® duty cycle-based grayscale capability enables the direct measurement of the adaptive matched filter. We will also show examples of multispectral and hyperspectral matched-filter images recorded with our visible spectrum prototype.
Validating Expert Systems: A Demonstration Using Personal Choice Expert, A Flexible Employee Benefit System

A method for validating expert systems, based on validation approaches from psychology and Turing's “imitation game,” is demonstrated using a flexible employee benefits expert system. Psychometric validation has three aspects: the extent to which the system and expert decisions agree (criterionrelated validity), the inputs and processes used by experts compared to the system (content validity), and differences between expert and novice decisions (construct validity). If these criteria are satisfied, then the system is indistinguishable from experts for its domain and satisfies the Turing Test. Personal Choice Expert (PCE) was designed to help employees of a Fortune 500 firm choose benefits in their flexible benefits system. Its recommendations do not significantly differ from those given by independent experts. Hence, if the system-independent expert agreement (criterion-related validity) were the only standard, PCE could be considered valid. However, construct analysis suggests that re-engineering may be required. High intra-expert agreement exists only for some benefit recommendations (e.g., dental care and long-term disability) and not for others (e.g., short-term disability, accidental death and dismemberment, and life insurance). Insights offered by these methods are illustrated and examined.
Intracellular Aggregation of Multimodal Silica Nanoparticles for Ultrasound-Guided Stem Cell Implantation

The promises of cardiac stem cell therapy have yet to be fully realized, in part because of poor survival and engraftment efficacy of implanted cells. Cells die after implantation owing to ischemia, inflammation, immune response, as well as mis-injection or implantation into fibrotic tissue. Imaging tools can help implant cells in areas of the heart most receptive to stem cell therapy and monitor the efficacy of treatment by reporting the viability, location, and number of implanted stem cells. We describe a multimodal, silica-based nanoparticle that can be used for cell sorting (fluorescence), real-time guided cell implantation ultrasound, and high-resolution, long-term monitoring by magnetic resonance imaging (MRI). The nanoparticle agent increased the ultrasound and MRI contrast of labeled human mesenchymal stem cells (hMSCs) 700 and 200% versus unlabeled cells, respectively, and allowed cell imaging in animal models for 13 days after implantation. The agent had no significant impact on hMSC cell metabolic activity, proliferation, or pluripotency, and it increased the production of many paracrine factors implicated in cardiac repair. Electron microscopy and ultrasound imaging suggest that the mechanism of action is in vivo aggregation of the 300-nm silica nanoparticles into larger silica frameworks that amplify the ultrasound backscatter. The detection limit in cardiac tissue was 250,000 hMSCs via MRI and 70,000 via ultrasound. This ultrasound-guided cell delivery and multimodal optical/ultrasound/MRI intracardiac cell-tracking platform could improve cell therapy in the clinic by minimizing misdelivery or implantation into fibrotic tissue.
Development Theory and the Cold War: The Influence of Politics on Latin American Structuralism

This paper analyzes the origins of economic development theory by focusing on the work of Raul Prebisch. When Prebisch put forward his theoretical framework, he was faced with the challenges of creating a foundation for development policies in the context of the Cold War. Moreover, Prebisch was immersed in a determined mentalite; he was part of a social network and institutional setting that transformed his ideas into an influential theory. The objective is to highlight that economic theories do not rely on natural laws, and rather result from a historical and social context and that economists are not passive, isolated theoreticians; they are socialized and directly impact the issues on which they theorize. To strengthen the argument, archival research on the Prebisch Papers at the UN Archives as well as interviews from the UN Oral History Project are included.
Use of Arrays of Releasable Microstructures for Selection of Single Cells and Colonies

Microfabricated arrays of individually releasable elements have been developed to enable cell analysis and isolation of cells from small cell samples, typically less than 4,000 cells. A cell suspension is added to the array and the cells are captured as the settle onto the individual elements. After capture, cells are cultured for the desired length of time. By plating single-cell suspensions of fewer cells than elements, one or fewer cells are captured per element. Prolonged culture then enables growth of clonal colonies on the array. Standard microscopic imaging is used to identify cells or colonies of interest, and individual elements containing target cells are then released and collected. Creation of arrays composed of elements with various geometries and three dimensional structures has been accomplished to maximize capture efficiency of cells plated on the array and growth of clonal colonies. This work has led to the ability to pattern both adherent and nonadherent cells, with subsequent selection and collection of single cells or clonal colonies with unique characteristics. Surface modification of the elements has been accomplished to enrich the cell samples for particular cell types. Selective release of the individual elements along with the resident cells has been enhanced to achieve high collection efficiencies of viable cells which can then be expanded under standard tissue culture conditions. Three dimensional elements have also been created that enable cell growth in isolated cell culture microenvironments which will prove valuable for cell-cell interaction studies.
Evolving role of MRI in Crohn's disease

MR enterography is playing an evolving role in the evaluation of small bowel Crohn's disease (CD). Standard MR enterography includes a combination of rapidly acquired T2 sequence, balanced steady-state acquisition, and contrast enhanced T1-weighted gradient echo sequence. The diagnostic performance of these sequences has been shown to be comparable, and in some respects superior, to other small bowel imaging modalities. The findings of CD on MR enterography have been well described in the literature. New and emerging techniques such as diffusion-weighted imaging (DWI), dynamic contrast enhanced MRI (DCE-MRI), cinematography, and magnetization transfer, may lead to improved accuracy in characterizing the disease. These advanced techniques can provide quantitative parameters that may prove to be useful in assessing disease activity, severity, and response to treatment. In the future, MR enterography may play an increasing role in management decisions for patients with small bowel CD; however, larger studies are needed to validate these emerging MRI parameters as imaging biomarkers.
AN ALTERNATIVE APPROACH TO POINCARÉ SECTIONING IN WEAKLY NONLINEAR SYSTEMS

A large array of dynamical systems can be broadly classified as weakly nonlinear, where a common feature is the presence of dual time-scale dynamics. Often it is desirable to isolate the dynamics at one time scale (typically the slower time scale), and this paper presents a generic phase-sensitive detection method that successfully isolates the slow-time dynamics, stripping off the less-relevant and often dominant fast-time dynamics. We shall also show for the first time, under certain phase considerations, the equivalence of the present method and the traditional Poincare section of the original full response. The method is first presented in theory and then applied to data from a numerical simulation of the forced spherical pendulum followed by data from a similar spherical pendulum experiment. The method is successful provided certain conditions apply for phase stationarity.
Stimulus-secretion coupling and insulin secretion in aging: evaluation of glucose oxidation and ATP-sensitive potassium channel responsiveness

Abstract The purpose of this study was to evaluate possible age-related alterations in the glucose-stimulus/insulin-secretion coupling mechanism of islets of Langerhans. To this end, the interaction among insulin secretion, glucose oxidation, and ATP-sensitive potassium (K ATP ) channel responsiveness was determined in islets were of Langerhans isolated from 6-, 12-, and 26-month-old male Fischer 344 (F344) rats. Groups of 20 islets were incubated for 40 min at 37°C in a buffer containing: (1) either 1.7 or 11.1 mM glucose; (2) 1.2 μM glyburide and either 1.7 or 11.1 mM glucose; (3) 5 μM epinephrine and 11.1 mM glucose; or (4) 1.2 μM glyburide, 5 μM epinephrine, and either 1.7 or 11.1 mM glucose. Insulin release of islets incubated in the presence of glyburide and 1.7 or 11.1 mM glucose was greater than that of islets incubated in glucose alone, while glucose oxidation did not increase. Epinephrine inhibited insulin release and glucose oxidation did not increase. Epnephrine inhibited insulin release at 11.1 mM glucose. No effect of age was observed in any of the treatment categories. These results indicated that if age-related alterations are occurring in glucose-stimulus/insulin-secretion coupling, then such alterations are not associated with changes in K ATP channel-mediated responsiveness.
Advances in the Treatment of Urinary Incontinence in Women

Urinary incontinence in women is quite prevalent today and management can be costly. Urinary incontinence can be minimal or quite bothersome, limiting activities of daily living. It is subdivided into urgency urinary incontinence, stress urinary incontinence, and mixed urinary incontinence. As such, treatment can vary immensely depending on the clinical presentations, ranging from behavioral modification to medicinal therapies to surgical procedures. First-line management for all urinary incontinence includes lifestyle and behavioral modifications. Historically, treatment options for urgency urinary incontinence were predominantly antimuscarinics, while more recent therapies include oral beta-3 agonist administration, sacral neuromodulation, onabotulinumtoxinA injection, and posterior tibial nerve stimulation. Stress urinary incontinence can be treated with a variety of urethral bulking agent injections or sling-based procedures using mesh, autologous fascia, or cadaveric fascia, as well as urethral intrasphincteric injections of autologous muscle-derived cells in new clinical trials. These recent advances that have been developed to help better curb urinary incontinence are discussed in this review.
Long-term turnover of cadmium metallothionein in liver and kidney following a single low dose of cadmium in rats

Abstract Rats were injected subcutaneously on two consecutive days with CdCl2, and sampled animals, killed at monthly intervals from 1 to 6 months thereafter, exhibited the presence of Cd,Zn-thionein in both the liver and kidney. At 6 months, hepatic thionein was present as the two major polymorphic forms previously demonstrated in short term Cd-injection studies. [35S]cysteine incorporation studies showed that both polymorphic forms of thionein underwent continual turnover at similar rates throughout the study. The slow hepatic and renal turnover of Cd, therefore, was not due to a highly stable form of Cd-thionein, but apparently due to an inefficient mechanism for excretion of Cd from these tissues. The Cd/Zn ratio of hepatic thionein remained relatively constant, suggesting that continual thionein induction results in a long-term hepatic trapping of Zn by thionein, but the ratio for renal thionein showed a marked increase during the course of the study.
Comparison of versions 6 and 7 3-hourly TRMM multi-satellite precipitation analysis (TMPA) research products

This paper examines differences between Version 6 (V6) and Version 7 (V7) 3-hourly TRMM (Tropical Rainfall Measuring Mission) Multi-Satellite Precipitation Analysis (TMPA 3B42) research products in JJA (June, July and August) and DJF (December, January and February) over a 13-year period from 1998 to 2010 on a global scale. Different surface types and rain regimes are considered in the comparison. The study finds that more rain events are found in V7 than those in V6 in both JJA and DJF, especially over oceans. Overall, both versions show a good agreement in moderate and heavy rain regimes. High Pearson’s correlation coefficients are found in tropical rain band regions. Histograms of both versions are very similar; however higher frequencies of rain events are found in V7 in light rain regime, especially over oceans, than those in V6. For light rain, rainfall estimates in V6 are less than those in V7 over land and oceans in both seasons. For moderate rain, rainfall estimates in V6 are larger than those in V7 over land in most years. Over oceans, it is a mixed situation in which V6 > V7 for some years and V6 < V7 for the other years. For heavy rain, rainfall estimates in V6 are larger than those in V7 throughout all JJA and DJF seasons for both land and oceans, which is also shown in a case study. Large variance in the individual differences is found in light rain and less in heavy rain. No apparent trends are observed. For light rain, all statistics support that there is an uncertainty issue in both versions.
Third-Order Elastic Constants of Copper at Low Temperature

The six third-order elastic constants of copper were determined at 295, 77, and 4.2\ifmmode^\circ\else\textdegree\fi{}K from measurements of the change in the velocity of sound accompanying the application of a uniaxial stress. Irradiation with neutrons or $\ensuremath{\gamma}$ rays as well as dilute alloy additions was used in an attempt to pin the dislocations so that their effects could be eliminated. It was found that dislocation still contributed to the measurements even though the experimental data were linear and reproducible and showed no changes in ultrasonic attenuation with stress. The ultimate criterion for determining when the dislocation effects had been eliminated was the comparison of the pressure derivatives of the second-order elastic constants calculated from the uniaxial stress measurements with the pressure derivatives obtained by direct measurement. Only the neutron-irradiated sample passed this test, and all the results presented were obtained on this sample. At room temperature the third-order elastic constants agree with those obtained by Hiki and Granato. At 4.2\ifmmode^\circ\else\textdegree\fi{}K, the results are ${C}_{111}=\ensuremath{-}20\ifmmode\pm\else\textpm\fi{}2$, ${C}_{112}=\ensuremath{-}12\ifmmode\pm\else\textpm\fi{}1.5$, ${C}_{123}=\ensuremath{-}5\ifmmode\pm\else\textpm\fi{}1.5$, ${C}_{144}=\ensuremath{-}1.3\ifmmode\pm\else\textpm\fi{}0.2$, ${C}_{166}=\ensuremath{-}7.1\ifmmode\pm\else\textpm\fi{}0.25$, and ${C}_{456}=+0.25\ifmmode\pm\else\textpm\fi{}0.08{10}^{12}$ dyn/${\mathrm{cm}}^{2}$. It should be noted that these results do not satisfy the Cauchy relations ${C}_{112}={C}_{166}$ and ${C}_{123}={C}_{144}={C}_{456}$. A value of the Gr\"uneisen $\ensuremath{\gamma}$ in the limit of low temperatures was calculated and found to be within the experimental error of the value obtained from thermal-expansion measurements.
Differing Neurotoxic Potencies of Methamphetamine, Mazindol, and Cocaine in Mesencephalic Cultures

The potent reinforcing effects of methamphetamine and cocaine are thought to be mediated by their interactions with CNS dopamine neurons. Both stimulants share the ability to block dopamine uptake potently, and methamphetamine can release cytoplasmic dopamine as well. There is also abundant evidence demonstrating the neurotoxic effects of methamphetamine. There are, however, limited studies that attempt to discern the neurotoxic mechanisms of these agents. The purpose of the present study was to characterize and compare the chronic in vitro effects of methamphetamine, cocaine, and the dopamine uptake blocker, mazindol, on cultured fetal mesencephalic dopamine neurons. Our studies examined biochemical mechanisms to evaluate the contribution of reuptake blockade versus release of dopamine. Using a dispersed cell preparation of fetal mesencephalon, cultures were treated for 5 days with the three uptake blockers. Dopamine function was assessed by measuring high-affinity [3H]dopamine uptake and by examining cultures for the presence of tyrosine hydroxylase-immunopositive neurons. Nonspecific neurotoxicity was assessed by staining for neuron-specific enolase and measuring lactate dehydrogenase activity. The results indicate that repeated administration of high concentrations of methamphetamine (10(-4) and 10(-3) M) caused a generalized neurotoxicity whereas the effects of 10(-5) M methamphetamine appeared to be specific to dopamine cells. Likewise, treatment of the cultures with mazindol (10(-6) M) resulted in reduced dopamine uptake while not significantly affecting neuron-specific enolase or tyrosine hydroxylase immunostaining. On the other hand, repeated exposure to cocaine (10(-5) and 10(-4) M) did not alter dopaminergic function in these cultures. The different mechanisms of action of these stimulants may explain the differences in neurotoxic potency of these compounds.(ABSTRACT TRUNCATED AT 250 WORDS)
Neural Data Compression with Wavelet Transform: A Vocabulary Based Approach

An algorithmic approach to develop the vocabulary of the nervous system and to use the vocabulary to communicate with the outside world is presented. The vocabulary is constructed using wavelet analysis of the recorded waveforms. Spikes of different frequency and amplitude from different channels are identified to construct unique signatures and relate them to physiological activities. A vocabulary-based communication of recorded action potentials renders two major advantages: a) it allows transmission of recorded data with large compression, thus, saving power and communication bandwidth of the integrated telemetry device; b) it helps easy mapping of alphabets in the vocabulary to muscular dynamics, which facilitates micro-stimulation based neural prostheses. In this work, we study the effectiveness of the proposed approach in neural data compression. Simulation results on pre-recorded data from the buccal nerves of a sea-slug shows that the proposed approach results in up to 80X compression
Convergence of rod and cone signals in the cat's retina.

1. In an attempt to understand the convergence of rod and cone signals in the cat's retina, ganglion cells that received inputs from both rods and cones were stimulated using lights chosen to excite one or other receptor system or both together. 2. If a mesopic background was chosen to allow the ganglion cell to be excited by a blue-green test flash primarily through rods and a deep red flash primarily through cones, one light could not be alternated with the other without eliciting a response from the cell. 3. This appears to be a result of the different temporal properties of the scotopic and photopic systems. On the mesopic background responses to blue-green test flashes were transient. Responses to red test flashes arose with similar latency, but were more sustained. 4. Rod and cone systems responded with similar latencies in the presence of the mesopic background that substantially light-adapted the rod system but left the full sensitivity of the cone system undiminished. When equivalently light-adapted, the cone system was faster. 5. When brief flashes that acted through rods were presented with flashes that acted through cones the ganglion cell's response was the sum of the responses to the two flashes presented separately, as long as the flashes were weak. This linear relation ceased to hold when flashes were strong, but the breakdown appears not to be the result of mutual inhibition between rod and cone signals. 6. When a background light excited both rod and cone systems it appeared to reduce sensitivity independently in each. 7. The scotopic and photopic receptive fields of a given ganglion cell always were of the same type, on- or off-centre, and, within the limits of measurement, the central regions of the receptive fields were concentric and both the same size.
Characterization and Prognostic Value of Persistent Hyponatremia in Patients With Severe Heart Failure in the ESCAPE Trial

Background: Mild hyponatremia is relatively common in patients hospitalized with heart failure (HF). To ourknowledge,theassociationofhyponatremiawithoutcomes has not been evaluated in the context of inhospital clinical course including central hemodynamics and changes in serum sodium level. Methods:The ESCAPE trial (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) was a randomized, controlled study designed to evaluate the utility of a pulmonary artery catheter plus clinical assessment vs clinical assessment alone in guiding therapy in patients hospitalized with New York Heart Association class IV HF due to systolic dysfunction (left ventricular ejection fraction 30%). A Cox proportional hazards model with baseline serum sodium level as a continuous variable was used to examine the association of serum sodium level with 6-month postdischarge mortality, HF rehospitalization, and death or rehospitalization. A categorical analysis was also performed comparing persistent and corrected hyponatremia. Results:Atotalof433hospitalizedpatientswithHFwere enrolledinESCAPE.Hyponatremia(serumsodiumlevel 134 mEq/L) was present in 103 patients (23.8%). (To convert serum sodium to millimoles per liter, multiply by1.0.) Ofthese,71hadpersistenthyponatremia(68.9%). Hyponatremiawasassociatedwithhigher6-monthmortality after covariate adjustment (hazard ratio [HR] for each 3-mEq/L decrease in sodium level, 1.23; 95% confidence interval [CI], 1.05-1.43) (P=.01). After controllingforbaselinevariablesandclinicalresponse,wefound that patients with persistent hyponatremia had an increasedriskofall-causemortality(31%vs16%;HR,1.82) (P=.04), HF rehospitalization (62% vs 43%; HR, 1.52) (P=.03),anddeathorrehospitalization(73%vs50%;HR, 1.54) (P=.01) compared with normonatremic patients.
Securing passwords against dictionary attacks

The use of passwords is a major point of vulnerability in computer security, as passwords are often easy to guess by automated programs running dictionary attacks. Passwords remain the most widely used authentication method despite their well-known security weaknesses. User authentication is clearly a practical problem. From the perspective of a service provider this problem needs to be solved within real-world constraints such as the available hardware and software infrastructures. From a user's perspective user-friendliness is a key requirement.In this paper we suggest a novel authentication scheme that preserves the advantages of conventional password authentication, while simultaneously raising the costs of online dictionary attacks by orders of magnitude. The proposed scheme is easy to implement and overcomes some of the difficulties of previously suggested methods of improving the security of user authentication schemes.Our key idea is to efficiently combine traditional password authentication with a challenge that is very easy to answer by human users, but is (almost) infeasible for automated programs attempting to run dictionary attacks. This is done without affecting the usability of the system. The proposed scheme also provides better protection against denial of service attacks against user accounts.
Soviet and Japanese oversnow vehicles

Abstract The Soviet Union has an overwhelming need for oversnow and adverse terrain transport since by their own definition over 60% of their country is considered as Arctic. They have developed a wide range of configurations and types of vehicles to fit their production capabilities and needs. Their vehicles in general are not sophisticated but rather emphasize ease of maintenance and simplicity. Their research however is based on investigating even exotic vehicle configurations. Japan on the other hand has limited its work to a small number of vehicles to fit their limited needs in the Northern Islands. Their research has been based mainly on the development and improvement of a snow/road track which can be used to meet their specialized military requirements.
Toward micro-scale spatial modeling of gentrification

A simple preliminary model of gentrification is presented. The model is based on an irregular cellular automaton architecture drawing on the concept of proximal space, which is well suited to the spatial externalities present in housing markets at the local scale. The rent gap hypothesis on which the model's cell transition rules are based is discussed. The model's transition rules are described in detail. Practical difficulties in configuring and initializing the model are described and its typical behavior reported. Prospects for further development of the model are discussed. The current model structure, while inadequate, is well suited to further elaboration and the incorporation of other interesting and relevant effects.
Blind MIMO Channel Estimation Based on Structured Transmit Delay

This paper aims to relax the restrictive conditions on blind MIMO channel identification by exploiting structured transmitter design. First, a simple structured transmit delay scheme is proposed, in which each antenna transmits an independent zero-padded data stream. Secondly, a second-order statistics based blind channel estimation algorithm is developed. Simulation results demonstrate that the proposed approach is robust in MIMO environment, even if when there are common zeros among the sub-channels.
Review: Lupus nephritis: pathologic features, epidemiology and a guide to therapeutic decisions.

Systemic lupus erythematosus may present with renal manifestations that frequently are difficult to categorize and lupus nephritis is an important predictor of poor outcome. The type and spectrum of renal injury may remain undiagnosed until full-blown nephritic and/or nephrotic syndrome appear with increased risk of end-stage renal disease. These abnormalities occur within the first few years after the diagnosis of lupus is made on clinical grounds and with the support of laboratory tests in high risk patients. An early renal biopsy is helpful in patients with an abnormal urinalysis and/or reduced glomerular filtration rate and the results form the basis for therapeutic decisions. The biopsy also provides vital prognostic information based on histological categorization of different types of lupus nephritis, the degree of activity, chronicity and the immunopathogenesis. In the current armamentarium, the use of cyclophosphamide and azathioprine and recently mycophenolate mofetil, reduce morbidity and maint...
Picking Up Artifacts: Storyboarding as a Gateway to Reuse

Storyboarding offers designers the opportunity to illustrate a visual narrative of use. Because designers often refer to past ideas, we argue storyboards can be constructed by reusing shared artifacts. We present a study in which we explore how designers reuse artifacts consisting of images and rationale during storyboard construction. We find images can aid in accessing rationale and that connections among features aid in deciding what to reuse, creating new artifacts, and constructing. Based on requirements derived from our findings, we present a storyboarding tool, PIC-UP, to facilitate artifact sharing and reuse and evaluate its use in an exploratory study. We conclude with remarks on facilitating reuse and future work.
Addiction and pain.

The use of opioid medications for analgesia is associated with concerns about adverse side effects and the potential for development of physical dependence, tolerance, or addiction. Pain often is undertreated, which may provoke drug-seeking behavior by patients. Physicians must assess requests for more pain medication as stemming from either undertreatment of pain, development of physical tolerance, or addiction. Important tools for addiction screening include the use of questionnaires, patient interviews, and lab tests. In this study, the physiological and behavioral consequences of chronic pain and its treatment with opioids, along with guidelines for prescribing opioid pain medication, are presented.
Tetramethylenedisulfotetramine Alters Ca2+ Dynamics in Cultured Hippocampal Neurons: Mitigation by NMDA Receptor Blockade and GABAA Receptor-Positive Modulation

Tetramethylenedisulfotetramine (TETS) is a potent convulsant that is considered a chemical threat agent. We characterized TETS as an activator of spontaneous Ca²⁺ oscillations and electrical burst discharges in mouse hippocampal neuronal cultures at 13-17 days in vitro using FLIPR Fluo-4 fluorescence measurements and extracellular microelectrode array recording. Acute exposure to TETS (≥ 2 µM) reversibly altered the pattern of spontaneous neuronal discharges, producing clustered burst firing and an overall increase in discharge frequency. TETS also dramatically affected Ca²⁺ dynamics causing an immediate but transient elevation of neuronal intracellular Ca²⁺ followed by decreased frequency of Ca²⁺ oscillations but greater peak amplitude. The effect on Ca²⁺ dynamics was similar to that elicited by picrotoxin and bicuculline, supporting the view that TETS acts by inhibiting type A gamma-aminobutyric acid (GABA(A)) receptor function. The effect of TETS on Ca²⁺ dynamics requires activation of N-methyl-D-aspartic acid (NMDA) receptors, because the changes induced by TETS were prevented by MK-801 block of NMDA receptors, but not nifedipine block of L-type Ca²⁺ channels. Pretreatment with the GABA(A) receptor-positive modulators diazepam and allopregnanolone partially mitigated TETS-induced changes in Ca²⁺ dynamics. Moreover, low, minimally effective concentrations of diazepam (0.1 µM) and allopregnanolone (0.1 µM), when administered together, were highly effective in suppressing TETS-induced alterations in Ca²⁺ dynamics, suggesting that the combination of positive modulators of synaptic and extrasynaptic GABA(A) receptors may have therapeutic potential. These rapid throughput in vitro assays may assist in the identification of single agents or combinations that have utility in the treatment of TETS intoxication.
Dual-Mode Propellant Properties and Performance Analysis of Energetic Ionic Liquids

Imidazole-based energetic ionic liquids capable of dual-mode chemical monopropellant or bipropellant and electric electrospray rocket propulsion are investigated. A literature review of ionic liquid physical properties is conducted to determine an initial set of ionic liquids that show favorable physical properties for both modes, followed by numerical and analytical performance simulations. Of the ionic liquids considered in this study, [Bmim][dca], [Bmim][NO3], and [Emim][EtSO4] meet or exceed the storability properties of hydrazine and their electrochemical properties are comparable to [Emim][Im], the current state-of-the-art electrospray propellant. Simulations show that these liquids do not perform well as chemical monopropellants, having 10-22% lower specific impulse due to their lack of oxidizing species. The ionic liquids show acceptable bipropellant performance when burned with standard oxidizers, having specific impulse 6-12% lower than monomethylhydrazine and nitrogen tetroxide combination. Considering these ionic liquids as a fuel component in a binary monopropellant mixture with hydroxyl ammonium nitrate shows 1-3% improved specific impulse over some green monopropellants, while retaining a higher molecular weight, reducing the number of electrospray emitters required to produce a given thrust level. More generally, ionic liquids with oxidizing anions perform well as chemical monopropellants while retaining high molecular weight desirable for electrospray propulsion missions.
Chlamydial Variants Differ in Ability To Ascend the Genital Tract in the Guinea Pig Model of Chlamydial Genital Infection

ABSTRACT An important question in the study of chlamydial genital tract disease is why some women develop severe upper tract disease while others have mild or even “silent” infections with or without pathology. Animal studies suggest that the pathological outcome of an infection is dependent upon both the composition of the infecting chlamydial population and the genotype of the host, along with host physiological effects, such as the cyclical production of reproductive hormones and even the size of the infecting inoculum or the number of repeated infections. In this study, we compared two variants of Chlamydia caviae, contrasting in virulence, with respect to their abilities to ascend the guinea pig genital tract. We then determined the effect of combining the two variants on the course of infection and on the bacterial loads of the two variants in the genital tract. Although the variants individually had similar infection kinetics in the cervix, SP6, the virulent variant, could be isolated from the oviducts more often and in greater numbers than the attenuated variant, AZ2. SP6 also elicited higher levels of interleukin 8 (IL-8) in the lower genital tract and increased leukocyte infiltration in the cervix and uterus compared to AZ2. When the two variants were combined in a mixed infection, SP6 outcompeted AZ2 in the lower genital tract; however, AZ2 was able to ascend the genital tract as readily as SP6. These data suggest that the ability of SP6 to elicit an inflammatory response in the lower genital tract facilitates the spread of both variants to the oviducts.
Customizable cryptographic architecture for government and military communications applications

With the continued international proliferation of military communication technology, equipment vendors are challenged to provide communications security (COMSEC) solutions that are appropriate for these applications. Addressing these challenges is complicated by the fact that no encryption standard exists for international government and military communications applications. Harris Corporation has leveraged its expertise in encryption algorithm design, type 1 hardware design, and embedded system design to develop a cost-effective, customizable encryption algorithm for military and government communications applications. The algorithm is the second generation of the highly successful Citadel/sup /spl trade// cryptographic algorithm. It was designed against a military/government threat model and specifically addresses the rigorous requirements dictated by these applications. It does so in a manner that is both flexible and cost effective. This paper will begin with a brief review of the requirements for military-grade encryption products. It will continue with an overview of the algorithm design along with discussion on the features responsible for its military grade strength.
Value of college education mediating the predictive effects of causal attributions on academic success

Causal attributions (explanations for outcomes) have been found to predict college students’ academic success; however, not all students attributing success or failure to adaptive (i.e., controllable) causes perform well in university. Eccles et al.’s (Achievement and achievement motives. W.H. Freeman, San Francisco, pp 75–145, 1983) expectancy-value theory posits that subjective task value likely mediates the relationship between causal attributions and academic success. The current study tested value as a mediator of the relationship between causal dimensions and academic success measured by perceived academic success and academic emotions. Participants were 389 college students from a Midwestern university. Results suggested that students who attributed their failure to internal, personally controllable causes perceived themselves as more successful if they also valued college education as enjoyable, useful, and/or rated its cost value as low. Findings also revealed that value of college education mediated the predictive effects of causal dimensions on several academic emotions, including pride, anger, shame, and guilt. Theoretical developments of attribution theory as well as practical implications for improving college students’ academic motivation, success, and positive emotions are discussed.
The HLA-D Region: Serology, Structure, Tissue Distribution, and Function of Human Class II Molecules and Their Antigenic Determinants

DR, DQ, and DP Molecules are Structurally Distinct by N-terminal Amino Acid Sequence Analysis. Amino acid sequences for alpha chains of the three types of molecules are shown in Table 1. The major populations of molecules that carry the DRw52- like determinants recognized by monoclonal antibodies I-LR2 (Nadler) or 7.3.19.4 (Koning) and also those that bear DRw53 epitopes reactive with 109d6 (Winchester) are indistinguishable from DR molecules [1].
Sweat Gland Nerve Fiber Density by Skin Biopsy: Frequency of Abnormalities and Clinical Characteristics (S26.001)

OBJECTIVE: To determine the frequency of abnormal sweat gland nerve fiber density (SGNFD) by skin biopsy and determine and compare the clinical characteristics of patients with the sole finding of either abnormal SGNFD or abnormal epidermal nerve fiber density (ENFD). BACKGROUND: Small fiber sensory neuropathy has been diagnosed based on ENFD findings by skin biopsy. More recently, determination of SGNFD has been used for the same purpose, although little is known about its clinical utility or the characteristics of patients with the sole finding of an abnormal SGNFD. DESIGN/METHODS: Retrospective chart review of all patients with skin biopsies obtained within the last five years at the Weill Cornell Peripheral Neuropathy Center. All patients typically had sensory symptoms with preserved strength and normal/non-diagnostic routine EMG/NCS. RESULTS: Of the 218 cases (137 women, 81 men), 122 (56%) were Normal and 96 (44%) were Abnormal. The Abnormal group was subdivided into three groups: Abnormal SGNFD Only (28/96, 29%); Abnormal ENFD Only (29/96, 30%); and Abnormal SGND and ENFD (39/96, 41%). Patients with Abnormal SGNFD Only (when compared with patients with Abnormal ENFD Only) were predominantly male (93% vs 28%) and younger (mean age=42 vs 56). They were also more likely to have sensory symptoms involving the torso (36% vs 14.3%), less likely to have absent ankle reflexes (13% vs 54%) or impaired vibration sense on exam (43% vs 70%), and less likely to have a diagnosis of diabetes or glucose intolerance (20% vs 39%). CONCLUSIONS: An abnormal SGNFD was the sole finding in 30% of our abnormal subjects. Assessment of SGNFD may increase the ability to diagnose a small fiber neuropathy that would be missed by ENFD analysis alone. Patients with an abnormal SGNFD/normal ENFD may comprise a different clinical subset of small fiber neuropathy that is worth investigating prospectively. Disclosure: Dr. Weaver has nothing to disclose. Dr. Kim has nothing to disclose. Dr. Carey has nothing to disclose. Dr. Langsdorf has nothing to disclose. Dr. Chin has received personal compensation for activities with Grifols Bioscience.
Distributed Group Support Systems (DGSS)

This year represents the eighth consecutive year of the Distributed GSS mini-track. From the topics examined-change management, activity theory and intra-group diversity-to the methods employed-lab experiments, field studies and case studies-to the approaches taken-positivist, interpretivist and participative-the seven papers accepted this year represent a rich diversity of offerings and a sure sign that the field is indeed maturing.Three themes characterize the material presented in the seven chosen papers: The diversity of development methods used in developing Distributed GSS tools; the range of impacts-from positive to negative, and from anticipated to unanticipated-when Distributed GSS tools are introduced in different environments; and the importance of group processes and structures in affecting group outcomes. Each of the papers in the mini-track that cut across these themes is summarized below. 01 Tuikka: Activity Theory is used to analyze situated interaction for purposes of developing a design approach that has designers and users interacting to co-construct a design reality. The process leads to shared virtual prototyping. 02 Nilsson, Josefsson and Ranerup: This is an empirical study investigating the management of unanticipated change-as contrasted with the management of anticipated change-when introducing groupware into a highly structured organizational environment. 03 Ocker: This study examines outcome quality and creativity as well as process satisfaction and group development in distributed groups engaging in strictly asynchronous interaction versus groups supported by a combination of face-to-face and asynchronous communication. 04 Huang and Lai: Citing a large body of research which indicates that GSS tend not to enhance group satisfaction, this study examines whether embedding a team-building framework in a GSS can enhance decision quality and process satisfaction. The answer may help explain the results of earlier research. 05 Anderson and Hiltz: Group process and consensus were studied in culturally heterogeneous versus culturally homogeneous groups. The interaction occurred in both co-located and distributed contexts. 06 Burke and Aytes: Interaction analysis is used to assess how groups develop procedural structures over time. Further analysis examines the groups' perceptions about their behaviors and their satisfaction with the structures generated. 07 Valin, Francu, Trefftz, and Marsic: This paper describes a series of experiments that assess the effectiveness of viewpoint sharing in collaboration by the use of a 3-D view-sharing tool compared with the use of telepointers.This year's selection of papers attests to the fact that as Distributed GSS technologies grow and mature, so must the methods used to study them. The rapid advances in mobile computing and wireless networks offer rich new grounds for future Distributed GSS research.
Efficient Magnetron With a Virtual Cathode

We use particle-in-cell (PIC) computer simulations to demonstrate high-efficiency operation of a magnetron with diffraction output (MDO) that uses a virtual cathode in the interaction space instead of a physical cathode. The cathode generating the electron beam is external to the MDO interaction space and, therefore, is immune from electron bombardment, pulse shortening, decreasing electron efficiency, and frequency shift attributed to expanding cathode plasma. Electronic efficiencies comparable to those achieved with the MDO with a transparent cathode have been achieved in the simulations.