cssi/SciSciGPT-SciSciNet huggingface dataset:
Multidetector row CT angiography of living related renal donors: is there a need for venous phase imaging?

Abstract Objective To prospectively evaluate whether renal venous anatomy can be detected from arterial phase images of multidetector row CT (MDCT) of renal donors. Material and methods Institutional review board approved our study protocol with waiver of consent. Forty-eight consecutive renal donors (age range, 21–56 years; M:F, 20:28) referred for MDCT evaluation were included. Two sub-specialty radiologists performed an independent and separate evaluation of renal venous anatomy in arterial and venous phase images. Opacification of renal venous structures was scored on a five-point scale (1-not seen; 3-minimal opacification; 5-excellent opacification). Arterial and venous phase opacification scores were compared by Wilcoxon signed rank test. Results Both readers detected all renal venous anomalies in arterial as well as venous phase images. Each reader detected accessory right renal veins ( n =14), retroaortic left renal vein ( n =2), circumaortic left renal vein ( n =1), and left renal hilar arteriovenous malformation ( n =1) in arterial phase images. Retroaortic left renal venous branch was difficult to differentiate from lumbar vein (reader-1, n =1; reader-2, n =2) in both arterial and venous phase images. Sensitivity of detection of renal veins, left adrenal, gonadal and lumbar veins in arterial phase images was 100, 83–88, 100, and 85–90%, respectively. As expected, venous phase images showed significantly greater opacification of renal veins, left gonadal, adrenal and lumbar veins ( p p Conclusions Arterial phase MDCT images alone can be used to detect renal venous anomalies, and to identify small left renal venous branches namely, the left gonadal, adrenal and lumbar veins in renal donors. Venous phase MDCT acquisition is not necessary for evaluation of renal venous anatomy in renal donors.
Kinetic studies of mammalian and microbial cholesterol esterases in homogeneous aqueous solutions

Abstract The kinetics of one microbial and two mammalian cholesterol esterases have been examined using a variety of aryl acetates in homogeneous solution. The mammalian enzymes behaved identically but differed somewhat from that of microbial origin. The reactions of all three were not affected by either electronic or hydrophobic characteristics. Taurocholic acid was without effect on the microbial enzyme; at low concentrations it inhibited the mammalian system, but when present in millimolar amounts notable increases in rate were discerned, attributable to the detergent effect on the enzyme.
Real-time stereographic display of volumetric datasets in radiology

A workstation for testing the efficacy of stereographic displays for applications in radiology has been developed, and is currently being tested on lung CT exams acquired for lung cancer screening. The system exploits pre-staged rendering to achieve real-time dynamic display of slabs, where slab thickness, axial position, rendering method, brightness and contrast are interactively controlled by viewers. Stereo presentation is achieved by use of either frame-swapping images or cross-polarizing images. The system enables viewers to toggle between alternative renderings such as one using distance-weighted ray casting by maximum-intensity-projection, which is optimal for detection of small features in many cases, and ray casting by distance-weighted averaging, for characterizing features once detected. A reporting mechanism is provided which allows viewers to use a stereo cursor to measure and mark the 3D locations of specific features of interest, after which a pop-up dialog box appears for entering findings. The system's impact on performance is being tested on chest CT exams for lung cancer screening. Radiologists' subjective assessments have been solicited for other kinds of 3D exams (e.g., breast MRI) and their responses have been positive. Objective estimates of changes in performance and efficiency, however, must await the conclusion of our study.
Photoelectric Time Differentiation in Laser Microprobe Optical Emission Spectroscopy

The laser microprobe as an instrument for sampling and generation of optical emission spectra for elemental analysis presents special noise problems. The microprobe vaporizes a sample, usually 10−12 10−6 grange, depending on the laser energy employed, and leaves a microscopic crater. While the duration of a Q-spoiled laser beam is usually less than 100 nsec and most of the optical noise occurs during this interval,1–7 the optically emitting plasma may persist for microseconds.2,4–7 Therefore such commonly used noise reduction techniques as signal averaging, tuned frequency detection, and derivative spectroscopy are not applicable. Since all photons of a given wavelength have the same energy, energy differentiation techniques cannot be employed.
Cation tracer diffusion in the thermoelectric materials Cu3Mo6Se8 and “β-Zn4Sb3”

Abstract The diffusion of radioactive tracers, Ag-110m diffusing in Cu3Mo6Se8 and Zn-65 diffusing in “β-Zn4Sb3”, was experimentally studied. Tracer concentration profiles were generated by diffusion-annealing samples in argon atmospheres containing 1–2% H2. The corresponding residual radioactivity profiles were measured and analyzed to determine tracer diffusion coefficients of Ag-110m diffusing in Cu3Mo6Se8 and of Zn-65 diffusing in “β-Zn4Sb3”. The temperatures investigated were between about 195 and 900 °C for Cu3Mo6Se8 and between about 195 and 475 °C for “β-Zn4Sb3”. It was found that the diffusion of Ag in Cu3Mo6Se8 and of Zn in “β-Zn4Sb3” is very fast, with tracer diffusion coefficients on the order of 10− 5 to 10− 6 cm2/s in the temperature ranges considered. The temperature dependencies of the tracer diffusion coefficients denoted above can be described by using Arrhenius-type relations. The values determined for activation energies are 18.70 ± 0.95 kJ/mol for the tracer diffusion of Ag-110m in Cu3Mo6Se8 and 11.07 ± 0.95 kJ/mol for the tracer diffusion of Zn-65 in “β-Zn4Sb3”. These values are comparable to the very low activation energy of 9.16 kJ/mol observed for the diffusion of Ag in the fast ion conductor α-Agl.
Numerical and experimental investigation of unsteady three-dimensional separation on axisymmetric bodies

Abstract The understanding of unsteady three-dimensional separation is lagging behind the understanding of two-dimensional separation due to its greater complexity and the limited amount of data for universal or canonical flow problems. Three-dimensional separation occurs, for example, when low aspect ratio devices such as submarines and torpedoes are operated at large angles of attack, α. Two low aspect ratio geometries, the DARPA Suboff bare hull geometry, which is a prototypical submarine shape, and a hemisphere-cylinder geometry were investigated. Numerical simulations and water tunnel experiments for the Suboff geometry for a Reynolds number based on diameter of Re = 10 , 000 show little flow separation at α = 30 ° . A hemisphere-cylinder geometry was derived by replacing the Suboff forebody with a hemisphere. Simulations and water tunnel experiments were carried out for Re = 2000 and 5000. For α = 10 ° a large shedding separation bubble is observed on the leeward side. For α = 30 ° two counter-rotating leeward vortices appear and shedding is reduced. Proper orthogonal decomposition and Fourier analysis in time are employed for investigating the unsteady fluid dynamics. Conclusions are drawn with respect to the mean flow topology and possibly relevant hydrodynamic instabilities.
The electronic spectrum of the μ-amido-decamminedicobalt(III) ion

The electronic spectrum of the binuclear μ-amido-decamminedicobalt(III) ion was determined. The two bands with maxima at 19,740 and 28,010 cm−1 may be attributed to d-d transitions of a d6 ion in C4ν symmetry for each (separate) cobalt atom. The very intense band with a maximum at 38,000 cm−1 is attributed to three L → M (reduction) charge transfer transitions. The electronic spectrum of a related binuclear ion, the μ-amido-chloroaquo-octamminedicobalt(III) ion may also be interpreted in terms of separate transitions on each cobalt atom.
A Means to an End: Studying the Existing Environment for Private Sector Participation in the Water and Sanitation Sector

Given that the degree of success of private sector participation in the water and sanitation sector is such a hotly debated topic, there is a need to empirically study the environment within which private investment currently exists. Using Logit estimation, and investigating 29 political, economic and demographic variables from 39 developing countries, it was found that neither the political nor demographic environments play a role in explaining the existence of private sector participation. However, the empirical estimates show that many economic variables do play a significant role. Furthermore, it is hypothesized that much of the determination of reaching financial closure with the private sector is due to proprietary conditions between the private sector and the governments involved.
Articulated Human Detection with Flexible Mixtures of Parts

We describe a method for articulated human detection and human pose estimation in static images based on a new representation of deformable part models. Rather than modeling articulation using a family of warped (rotated and foreshortened) templates, we use a mixture of small, nonoriented parts. We describe a general, flexible mixture model that jointly captures spatial relations between part locations and co-occurrence relations between part mixtures, augmenting standard pictorial structure models that encode just spatial relations. Our models have several notable properties: 1) They efficiently model articulation by sharing computation across similar warps, 2) they efficiently model an exponentially large set of global mixtures through composition of local mixtures, and 3) they capture the dependency of global geometry on local appearance (parts look different at different locations). When relations are tree structured, our models can be efficiently optimized with dynamic programming. We learn all parameters, including local appearances, spatial relations, and co-occurrence relations (which encode local rigidity) with a structured SVM solver. Because our model is efficient enough to be used as a detector that searches over scales and image locations, we introduce novel criteria for evaluating pose estimation and human detection, both separately and jointly. We show that currently used evaluation criteria may conflate these two issues. Most previous approaches model limbs with rigid and articulated templates that are trained independently of each other, while we present an extensive diagnostic evaluation that suggests that flexible structure and joint training are crucial for strong performance. We present experimental results on standard benchmarks that suggest our approach is the state-of-the-art system for pose estimation, improving past work on the challenging Parse and Buffy datasets while being orders of magnitude faster.
Stalin, the Leningrad Affair, and the Limits of Postwar Soviet Russocentrism

Between 1949 and 1953 the USSR's second largest party organization was dealt a staggering blow during what has come to be known as the Leningrad Affair. Several thousand Soviet citizens ultimately fell victim to this enigmatic purge, including A. A. Kuznetsov, a VKP(b) Central Committee secretary, N. A. Voznesenskii, chair of USSR Gosplan, and M. I. Rodionov, chair of the Russian Federation's Council of Ministers. V. P. Volkov, an otherwise unremarkable party apparatchik, numbers among the many forgotten casualties. A department head in a Leningrad party district committee during the Second World War, Volkov was posted to the Moldavian SSR in 1945. There, while serving in various positions including party secretary of the Kishenev city committee, he irritated locals with his tendency to wax rhapsodic about his patron, Kuznetsov, who had just been promoted from Leningrad party chief to the Central Committee secretariat. Particularly objectionable was Volkov's frequent use of rhetoric like "us Leningraders," "in Leningrad, we do it like this," and "you need to learn to work from the 'best' group of Leningrad Bolsheviks under Comrade Kuznetsov."' Unsurprisingly, Kuznetsov's fall in early 1949 left Volkov exposed and scandal consumed him a little over a year later. But there is something very curious about the complaints contained in the semiliterate, anonymous denunciation that ultimately cost Volkov his career. This is because Volkov was accused of much more than just links to Kuznetsov or immodesty in regard to his Leningrad pedigree. According to the letter, Volkov had spread rumors within the Kishinev party committee about the "formation of a RSFSR party Central Committee to be
Optimal Admission Control for Tandem Queues With Loss

We consider a two-station tandem queue loss model where customers arrive to station 1 according to a Poisson process. A gatekeeper who has complete knowledge of the number of customers at both stations decides to accept or reject each arrival. A cost c1 is incurred if a customer is rejected, while if an admitted customer finds that station 2 is full at the time of his service completion at station 1, he leaves the system and a cost c2 is incurred. Assuming exponential service times at both stations, an arbitrary but finite buffer size at station 1 and a buffer size of one at station 2, we show that the optimal admission control policy for minimizing the long-run average cost per unit time has a simple structure. Depending on the value of c2 compared to a threshold value c*, it is optimal to admit a customer at the time of his arrival either only if the system is empty or as long as there is space at station 1. We also provide the closed-form expression of c*, which depends on the service rates at both stations, the arrival rate and c1.
Cyclic AMP Production in Rat Calvaria in Vitro: Interaction of Prostaglandins with Parathyroid Hormone

We studied the cAMP response of cultured rat calvaria to parathyroid hormone (PTH) and prostaglandins (PG) in order to test the hypothesis that PTH action is mediated by PG. PTH and PGE1 each caused an 8-fold increase in tissue cAMP during 15 min incubation. There was an additive response to the combination of the two agonists at maximally effective individual concentrations. Similar results were obtained when adenylate cyclase activity in bone homogenates was measured. Calvaria incubated for 60 min with PGE1 were desensitized to further stimulation by PGE1, but responded normally to PTH. Indomethacin, aspirin and phenylbutazone, 10−5M, had no effect on the cAMP response to PTH. At millimolar concentration these agents did block the hormone response; however, the response to exogenous PGE1 and the fluoride-sensitive adenylate cyclase were also inhibited. Thus, it appears that the effects of high concentrations of the anti-inflammatory drugs on cAMP formation are non-specific. Our results suggest that rece...
Posterior Instability of the Shoulder Following Thermal Capsulorrhaphy for Multidirectional Instability

Patients with multidirectional instability (MDI) of the shoulder can be treated with arthroscopic thermal capsulorrhaphy. However, recent literature suggests that complications and failures associated with this technique are on the rise. We present the case of a 30-year-old female patient who was treated for a failed thermal capsulorrhaphy. She had undergone this treatment of her left shoulder for MDI but had persistent pain with overhead activities and clicking in the posterior shoulder. Her history and physical examination were consistent with persistent posterior unidirectional instability of the shoulder. Magnetic resonance imaging showed a possible separation of the capsule from the posterior glenoid. After conservative management had been attempted several times, an arthroscopic repair was performed. At surgery, the anterior and inferior capsule appeared to be tight. However, the posterior capsule was extremely lax and patulous, but intact. A posterior capsule plication was performed arthroscopically, along with a rotator interval closure. Postoperatively, the patient was maintained in a sling that kept the arm in neutral rotation. At 6 weeks, the sling was removed, and a slow, progressive program of therapy was initiated. Stress on the posterior capsule was not permitted for 3 months. At 1-year follow-up, the patient had full pain-free range of motion and returned to participation in sports without limitation.
Implant-supported single crowns predictably survive to five years with limited complications.

Article Title and Bibliographic Information A systematic review of the 5-year survival and complication rates of implant-supported single crowns. Jung RE, Pjetursson BE, Glauser R, Zembic A, Zwahlen M, Lnag NP. Clin Oral Implants Res 2008;19(2):119-30. Reviewer Thomas Salinas, DDS Steven Eckert, DDS, MS Purpose/Question The purpose of this study was to evaluate the 5-year survival of implant-supported crowns and to identify the incidence of biologic and mechanical complications. Source of Funding Information not available. Type of Study/Design Systematic review with meta-analysis of data. Level of Evidence Level 2: Limited-quality, patient-oriented evidence Strength of Recommendation Grade Grade B: Limited quality patient oriented evidence
Banking in the theory of finance

Abstract Banks are financial intermediaries that issue deposits and use the proceeds to purchase securities. This paper argues that when banking is competitive, these portfolio management activities in principle fall under the Modigliani-Miller theorem on the irrelevance of pure financing decisions. It follows that there is no need to control the deposit creation or security purchasing activities of banks to obtain a stable general equilibrium with respect to prices and real activity. In practice, however, banks are forcibly involved in the process by which a pure nominal commodity or unit of account is made to play the role of numeraire in a monetary system. The paper examines the nature of such a nominal commodity and how, through reserve requirements, banks get involved in making it a real economic good.
IRIS: a high-resolution midinfrared spectrometer for the upgraded 6.5-meter Multiple Mirror Telescope

In mid-1996, the Multiple Mirror Telescope (MMT) will be upgraded from its current configuration of six 1.8-meter primary mirrors to house a single 6.5-meter primary. To exploit the dramatic increase in collecting area and spatial resolution, as well as the high infrared quality of the observing site, we have designed a new spectrometer that will cover the thermal infrared (4 to 25 micrometer) at high spectral and spatial resolution. The design is based on the new generation of Si:As BIB detectors with 256 by 256 formats, which represent a substantial advance in array size at these wavelengths. The design consists entirely of reflecting optics, and is arranged to deliver diffraction-limited resolution longwards of 8 micrometers. A maximum spectral resolving power of R equals 15,000 is provided by an echelle grating. A lower resolution grating or a plane mirror for two-dimensional imaging may be substituted for the echelle.
Domain walls and the Holstein-Primakoff transformations

The problem of determining the interaction of spin waves in the presence of a domain wall is examined. The Hamiltonian for a ferromagnet with a uniaxial anisotropy is rewritten in terms of harmonic oscillators with the use of the Holstein-Primakoff transformations. In the continuum limit a nonrelativistic scalar field theory is obtained. The equation of motion in three spatial dimensions admits domain-wall solutions. The Hamiltonian is expanded about the classical solution and the quadratic terms are used to generate the spin-wave spectrum. The results are shown to be consistent with other methods. The space of states and propagators are exhibited, and the extension to the higher-order terms governing spin-wave interactions is discussed.
Determination of glutamine and glutamic acid in mammalian cell cultures using tetrathiafulvalene modified enzyme electrodes

Tetrathiafulvalene (TTF) mediated amperometric enzyme electrodes have been developed for the monitoring of L-glutamine and L-glutamic acid in growing mammalian cell cultures. The detection of glutamine was accomplished by a coupled enzyme system comprised of glutaminase plus glutamate oxidase, while the detection of glutamic acid was carried out by a single enzyme, glutamate oxidase. The appropriate enzyme(s) were immoblized on the Triton-X treated surface of tetrathiafulvalene modified carbon paste electrodes by adsorption, in conjunction with entrapment by an electrochemically deposited copolymer film of 1,3-phenylenediamine and resorcinol. Operating conditions for the glutamine enzyme electrode were optimized with respect to the amount of enzymes immoblized, pH, temperature and mobile phase flow rate for operation in a flow injection (FIA) system. When applied to glutamine and glutamic acid measurements in mammalian cell culture in FIA, the results obtained with enzyme electrodes were in excellent agreement with those determined by enzymatic analysis.
What Does the U.S. REIT Market Have in Store for Nonconventional Investors? The Case of Shariah Compliance

The authors model the behavior of a hypothetical investor who is interested in U.S. securities but is also interested in compliance with Islamic investment guidelines. They apply financial restrictions to a 1990–2010 sample of Shariah-recommended REITs. In cumulative performance tests, they find evidence of outperformance associated with compliance during the entire study period and during the early 2000s recession and the late 2000s financial crisis. In risk-adjusted tests with a univariate model, the authors also find consistent evidence of outperformance during the entire study period and in times of economic turbulence. Using multivariate models, they find that compliant portfolios do just as well as noncompliant portfolios. They conclude that financial compliance might be rewarding for Shariah-abiding investors who are interested in the U.S. REIT sector. In separate tests, the authors show that leverage and REIT performance are independent. Yet, they show anecdotal evidence that outperformance of compliant portfolios may imply efficiency of an underlying conservative, but not necessarily religious, strategy that avoids the excessive use of debt, interest, and cash.
Why Do Adolescents Say They Are Less Healthy Than Their Parents Think They Are? The Importance of Mental Health Varies by Social Class in a Nationally Representative Sample

OBJECTIVE: We sought to (1) confirm the discrepancy between parent-reported and youth-reported adolescent health in a nationally representative sample, (2) compare the predictors of parent-reported and adolescent self-reported health, and (3) determine whether the discrepancy between the 2 ratings differed by sociodemographic characteristics, particularly income. METHODS: Data were from the 2001-2002 National Health and Nutrition Examination Survey. A total of 1157 adolescents aged 12 to 15 years, representative of 16,227,827 US youth, were included. Youth and their parents reported on the youth's health status along with other indicators of health and illness and sociodemographic characteristics. To examine predictors of self-rated and parent-rated adolescent health (excellent to poor), bivariate analyses were conducted, followed by multiple linear regression adjusted for relevant covariates. All of the analyses were stratified by income (standardized poverty income index:1). RESULTS: Parents and youth differed in subjective judgments regarding the child's health, even when these differences were not supported by other health indicators (days of school missed because of illness or injury or days of poor mental or physical health). Poor adolescents reported worse self-rated health than higher-income youth, and their parents did also. In income-stratified multiple regression models, higher-income adolescents' and their parents' ratings were predicted by indicators of physical health. In contrast, poor youth and parent ratings were better predicted by mental health care use. Poor youth with a mental health visit in the last year reported better health, but their parents saw these mental health visits as an indication of poor health. CONCLUSIONS: The findings suggest that social class differences in subjective ratings of adolescents' health are related to the differential ways that youth and parents determine what constitutes health and are not simply a reflection of objective health status. Language: en
Ferric Perchlorate Complex Ion

SUTTON1, and later Sykes2, have reported association constants for the formation of ferric perchlorate complex ion, FeClO4++, although other investigators have been unable to find evidence for the existence of this species3,4. Inasmuch as perchloric acid and perchlorate salts are commonly used for maintaining constant ionic strength in physical-chemical measurements on the assumption that perchlorate ion does not complex appreciably with cations in aqueous solution, the question of the existence and extent of perchlorate complexing is a matter of some importance.
Quenching of the lowest benzene triplet state in the vapor phase by nitric oxide

Abstract the rate constant for quenching of the triplet state ( 3 B 1u ) of benzene vapor by nitric oxide has been determined from a study of the flash photosensitization of biacetyl phosphorescence. The rate constant has been found to be (1.08 ± 0.2) × 10 −11 cm 3 molecule −1 sec −1 . Although this value is much larger than expected, it is in agreement with rate constants reported for quenching of some liquid phase aromatics.
Genetic engineering: Unnatural selection

Evolving techniques for redesigning organisms have enormous potential but they must be matched with equally sophisticated methods for evaluating their benefits and risks.
Flux-corrected transport. III. Minimal-error FCT algorithms

Abstract This paper presents an error analysis of numerical algorithms for solving the convective continuity equation using flux-corrected transport (FCT) techniques. The nature of numerical errors in Eulerian finite-difference solutions to the continuity equation is analyzed. The properties and intrinsic errors of an “optimal” algorithm are discussed and a flux-corrected form of such an algorithm is demonstrated for a restricted class of problems. This optimal FCT algorithm is applied to a model test problem and the error is monitored for comparison with more generally applicable algorithms. Several improved FCT algorithms are developed and judged against both standard flux-uncorrected transport algorithms and the optimal algorithm. These improved FCT algorithms are found to be four to eight times more accurate than standard non-FCT algorithms, nearly twice as accurate as the original SHASTA FCT algorithm, and approach the accuracy of the optimal algorithm.
Tn epitopes, immunoreactive with ordinary anti-Tn antibodies, on normal, desialylated human erythrocytes and on Thomsen-Friedenreich antigen isolated therefrom☆

Abstract Hybridoma generation, using specifically, maximally desialylated human blood group O erythrocytes (T RBC) as immunogen, and biochemical studies suggested the presence of immunogenic Tn epitopes, GalNAcα- O , on T RBC. We therefore investigated by immunochemical means whether or not Tn-specific epitopes immunoreactive with anti-Tn antibodies present in ordinary human sera occur on T RBC and on Thomsen-Friedenreich (T) antigen prepared from them. We did detect the Tn epitope with such antibodies, in addition to the T epitope, on isolated T antigen. T RBC absorbed specifically, under standard conditions, 25–60% of the heterogeneous anti-Tn antibody populations in ordinary human sera of appropriately adjusted titer score. The anti-Tn eluted from T RBC had scores ranging from 6.5 to 35% of those of the unabsorbed parent sera. The varying fine specificities of eluted anti-Tn were demonstrated by inhibition of Tn RBC agglutination with putative haptens and antigens. Tn-specific haptens and antigens were the most. powerful inhibitors. Depending on the serum used to prepare the anti-Tn eluates, the antibodies could be divided into those that were inhibited well exclusively by GalNAcα- O derivatives and those that were also inhibited by Gal, notably by Galα- O derivatives and more strongly by GalNAc and Me-α-GalNAc. In the two reciprocal hemagglutination inhibition systems used, Tn-specific haptens were considerably more active than the T-hapten Galβl→3GalNAcα- O , and desiaiylated ovine submaxillary mucin (AS-OSM) had higher activity than T antigen. Inhibition of Tn RBC agglutination by haptens was uniformly more efficient than that of T RBC; this is, at least in part, due to the much higher negative charge of Tn as opposed to T RBC. In microprecipitin tests. Helix pomatia lectin was nearly as powerful a precipitin of T antigen as of AS-OSM. The importance of the terminal GalNAcα of T antigen for its precipitation with the Helix lectin was demonstrated by the very high and virtually exclusive inhibitory activity of Me-α-GalNAc and GalNAc. Our findings may contribute to comprehension of the significance of uncovered Tn in most carcinomas, and the role of anti-Tn as a “natural” anti-carcinoma antibody. They may also help illuminate the rare heterozygous, autosomal, apparently premalignant spot mutation that leads to Tn RBC in vivo .
A preliminary report on the use of cesium chloride in contrast radiography.

(1956). A preliminary report on the use of cesium chloride in contrast radiography. Acta Radiologica: Vol. 46, No. 5, pp. 635-639.
A navigable six-legged robot platform

This work addresses the navigability of a six-legged robot which is accomplished through the development of a simple discretized error correction method used in the closed-loop controller. The control is based on a kinematic model of the hexapod which is used to correct the heading and drift errors from the desired motion. Experimental validation of the controller?s performance is also presented.
SU‐E‐J‐93: Perfusion CT and Tumor Response for Patients with Mesothelioma

Purpose: A pilot study is underway to assess the viability of perfusion CT as an imaging modality for patients with mesothelioma, and to investigate correlations between changes in perfusion metrics and tumor burden measurements. Methods: Four patients were scanned with an IRB‐approved protocol using a 256‐slice CT scanner. Each perfusion scan consisted of time point data acquired for a 5.5cm axial extent at 120kVp and 100mAs every three seconds for one minute prior to the full‐thorax diagnostic scan, followed by five additional scans every five seconds after the diagnostic scan. The dose for each perfusion scan was estimated at 165mGy [CTDI], and dose‐length product was equivalent to approximately 1.5 chest CT scans. Perfusion CT scans were obtained at two sessions approximately six weeks apart. All timepoints from a single scan were co‐registered using a demons deformable registration algorithm to remove the effects of motion prior to the calculation of perfusion maps. Perfusion, blood volume, time‐to‐peak, peak enhancement, and mean transit time data maps were calculated using the slope method. Data map spatial statistics were calculated over manually defined regions of interest (ROIs) within the tumor and changes in data map values were correlated with tumor burden changes measured according to the Modified RECIST technique. Results: Tumor ROIs exhibited heterogeneous contrast uptake, ranging from no uptake to peak enhancement of 150HU. Median tumor perfusion and median tumor blood volume metrics were correlated with changes in tumor burden (rank correlation p=0.0054 and 0.0030, respectively), with “shrinking” tumors exhibiting decreased blood volume and perfusion metrics. Conclusions: We believe that perfusion CT has potential to become an imaging biomarker of tumor response for mesothelioma patients. Data presented in this study indicate that perfusion CT is a viable imaging modality for mesothelioma, and that changes in perfusion metrics correlate with changes in measured tumor burden.
Ensemble-Based Convergence Analysis of Biomolecular Trajectories

Assessing the convergence of a biomolecular simulation is an essential part of any careful computational investigation, because many fundamental aspects of molecular behavior depend on the relative populations of different conformers. Here we present a physically intuitive method to self-consistently assess the convergence of trajectories generated by molecular dynamics and related methods. Our approach reports directly and systematically on the structural diversity of a simulation trajectory. Straightforward clustering and classification steps are the key ingredients, allowing the approach to be trivially applied to systems of any size. Our initial study on met-enkephalin strongly suggests that even fairly long trajectories (approximately 50 ns) may not be converged for this small--but highly flexible--system.
Consistent occupational preferences and satisfaction, self concept, self acceptance and vocational maturity

Abstract This study explored the differences on variables of satisfaction, self-concept, self-acceptance, and vocational maturity between freshmen students who made congruent and incongruent occupational choices. The variables were operationally defined by the College Student Satisfaction Questionnaire, the Tennessee Self-Concept Scale, the Berger scales, and the Vocational Development Inventory. Congruent and incongruent current occupational choice groups were defined operationally using the Self Directed Search. The analysis of variance of the scale scores did not reveal the main effect of congruence to be significant. However, a second analysis using a more rigorous definition of congruence revealed the main effect of congruence to be significant for four satisfaction variables. Findings suggest that subjects in the congruent male group tend to report better maintenance of personal stability and greater satisfaction than subjects in the incongruent female group.
EL NIÑO EFFECTS ON THE DYNAMICS AND CONTROL OF ANISLAND ECOSYSTEM IN THE GULF OF CALIFORNIA

The tremendous increase in precipitation associated with the 1992-1993 El Nino profoundly affected terrestrial communities on arid islands in the Midriff region of the Gulf of California. In 1992, winter precipitation was 5.4 times the historical mean, and winter precipitation over the entire El Nino was the highest two-year amount ever recorded. Increased precipitation led to an explosion of annual plant growth on the previously barren (0-4% cover) islands: plant cover increased 10-160 times over what it had been. With the resumption of arid conditions in 1994, live plant cover returned to the low levels seen before the onset of El Nino. Insect abundance tracked this pulse in plant productivity and approximately doubled in 1992 and 1993 compared to 1991 levels. In 1994, the crash of annual plants caused insect densities to drop to the lowest levels recorded during the 5-yr study. El Nino also affected the composition of the insect assemblage. In the dry years 1990-1991, the assemblage was dominated by insects feeding on products originating in the ocean: detritivores/scavengers on shore drift of marine algae and carcasses, avian parasites, and detritivores of bird products. Herbivores were extremely rare. The heavy plant growth in 1992 stimulated large (40-190 times pre-El Nino levels) increases in herbivores. The great increases in land plant biomass and insect abundance are indicative of an important change in the dynamics of this system. Previously, most material flowing through the food webs of these islands originated directly or indirectly in the ocean. In contrast, during this El Nino, most material originated via productivity by terrestrial plants. Thus, wet El Ninos represent an agent that switches the system from one dependent primarily on allochthonous input to a system driven to a greater extent by in situ productivity. The influence of this pulse of terrestrial productivity extends beyond the El Nino years: the persistence and slow release of plant and detrital biomass reserves may also greatly affect dynamics for years after the El Nino event has passed. We suggest that large-scale climatic events such as El Nino may be long-lasting determinants of community dynamics rather than occasional disturbance events.
P2Y13 receptor is responsible for ADP-mediated degranulation in RBL-2H3 rat mast cells

Extracellular ADP is known to play many important physiological roles. In this study, we identified the P2Y(13) receptor in a rat mast cell line (RBL-2H3) and explored the functional role of ADP, its endogenous agonist. ADP induced both intracellular calcium mobilization and release of hexosaminidase (Hex). In an assay of intracellular calcium, ADP was 100-fold less potent than and equally efficacious as the P2Y(1) receptor-selective agonist MRS2365. However, ADP was more potent and efficacious than MRS2365 in inducing Hex release and in enhancing antigen-induced Hex release. ADP-induced intracellular calcium mobilization was blocked by phospholipase C inhibitor U73122 and by P2Y(1) receptor-selective antagonist MRS2500, but not by pertussis toxin (PTX), suggesting a mechanism mediated by the G(q)-coupled P2Y(1) receptor, but not P2Y(13) (G(i)-coupled) or P2X receptors. ADP-induced Hex release was blocked by PTX and a selective P2Y(13) receptor antagonist MRS2211, but not by MRS2500 or P2Y(1) receptor-specific siRNA, suggesting a G(i)-coupled P2Y(13) receptor-related mechanism. Measurement of gene expression confirmed high expression of both P2Y(1) and P2Y(13) receptors (in comparison to a previously reported P2Y(14) receptor) in RBL-2H3 cells. Thus, we demonstrated that ADP-mediated intracellular calcium mobilization and Hex release in RBL-2H3 cells are via P2Y(1) and P2Y(13) receptors, respectively. Selective antagonists of the P2Y(13) receptor might be novel therapeutic agents for various allergic conditions.
On the theory of cosmic-ray showers I the furry model and the fluctuation problem

Abstract The main problems regarding the shower formation by fast electrons are reviewed on the basis of a simplified model first proposed by Furry (§§ 1 and 2). A general method is developed for calculating the fluctuation in the number of particles after a thickness x of matter (§ 3). It is shown in § 4 that N 2 (x) can always be found when the average energy distribution F(E, x) is known. Using the approximate “cut-off” method the numerical values of N 2 - ( N ) 2 have been computed for the Furry model (see table on p. 358). The approach to the normal value of the fluctuation (corresponding to the Poisson distribution) is much slower than has been expected.
A Modeling Study of the Effects of Membrane Afterhyperpolarization on Spike Interval Statistics and on ILD Encoding in the Lateral Superior Olive

The lateral superior olive (LSO) is the first nucleus in the ascending auditory pathway that encodes acoustic level information from both ears, the interaural level difference (ILD). This sensitivity is believed to result from the relative strengths of ipsilateral excitation and contralateral inhibition. The study reported here simulated sound-evoked responses of LSO chopper units with a focus on the role of the heterogeneity in membrane afterhyperpolarization (AHP) channels on spike interval statistics and on ILD encoding. A relatively simplified cell model was used so that the effects of interest could be isolated. Specifically, the amplitude and time constant of the AHP conductance within a leaky integrate-and-fire (LIF) cell model were studied. This extends the work of others who used a more physiologically detailed model. Results show that differences in these two parameters lead to both the distinctive chopper response patterns and to the level-dependent interval statistics as observed in vivo. In general, diverse AHP characteristics enable an enhanced contrast across population responses with respect to rate gain and temporal correlations. This membrane heterogeneity provides an internal, cell-specific dimension for the neural representation of stimulus information, allowing sensitivity to ILDs of dynamic stimuli.
Tyre–road friction coefficient estimation based on tyre sensors and lateral tyre deflection: modelling, simulations and experiments

The estimation of the tyre–road friction coefficient is fundamental for vehicle control systems. Tyre sensors enable the friction coefficient estimation based on signals extracted directly from tyres. This paper presents a tyre–road friction coefficient estimation algorithm based on tyre lateral deflection obtained from lateral acceleration. The lateral acceleration is measured by wireless three-dimensional accelerometers embedded inside the tyres. The proposed algorithm first determines the contact patch using a radial acceleration profile. Then, the portion of the lateral acceleration profile, only inside the tyre–road contact patch, is used to estimate the friction coefficient through a tyre brush model and a simple tyre model. The proposed strategy accounts for orientation-variation of accelerometer body frame during tyre rotation. The effectiveness and performance of the algorithm are demonstrated through finite element model simulations and experimental tests with small tyre slip angles on different...
Accurate numerical simulations of vortex flows. I: Vortex breakdown

Abstract Vortex breakdown in uniform axial flow is investigated numerically by solving the Navier–Stokes equations using a hybrid spectral – finite difference method. Two Reynolds numbers and a high swirl number are considered with the lower Re -number resulting in axi-symmetric flow, that possesses an asymptotic state, and a higher Re -number, that leads to unsteady flow and a moderate spectral range. The structural properties of the vorticity field are analyzed in terms of vorticity lines and surfaces. A recirculation bubble and a wake emerge that undergo significant fluctuations.
A digital model of coupled oscillators

A new model of coupled oscillators is proposed and investigated. All phase variables and parameters are integer-valued. The model is shown to exhibit two types of motions, those which involve periodic phase differences, and those which involve drift. Traditional dynamical concepts such as stability, bifurcation and chaos are examined for this class of integer-valued systems. Numerical results are presented for systems of two and three oscillators. This work has application in digital technology.
Reversible Electrocatalytic Production and Oxidation of Hydrogen at Low Overpotentials by a Functional Hydrogenase Mimic

An efficient ligand combination: A new bis(diphosphine) nickel(II) complex (see picture) is described. A ΔG° value of 0.84 kcal mol^(−1) for hydrogen addition for this complex was calculated from the experimentally determined equilibrium constant. This complex displayed reversible electrocatalytic activity for hydrogen production and oxidation at low overpotentials, which are characteristic for hydrogenase enzymes.
Political Boundaries and Political Structure: The Limits of the Teuchitlan Tradition

Many social scientists have proposed a relationship between the structure of a boundary and that of the system it delimits. Substantial anthropological and historical research has found the same tendency in analyses of traditional political structure. A model based on these findings was applied to the Teuchitlan tradition of Classic-period West Mexico, a region where the degree of political complexity and unification has been a subject of debate. A focused study of the eastern boundary of the Teuchitlan Valley was undertaken to examine the nature of its political structure. Fieldwork located a number of defensive features forming a well-structured boundary system in the La Venta corridor that connects the Teuchitlan and Atemajac Valleys. Other fortifications ringing the Teuchitlan Valley strongly suggest that a defensive network had been established to monitor access into the core of the Teuchitlan area. A unitary, territorial form of administration (following the work of Southall and Luttwak) is proposed as a model for political dynamics in the core region, but a review of the evidence for the more-distant Teuchitlan architecture suggests that, at most, only a hegemonic form of control more akin to that of the segmentary state was exercised outside of the core valley. A connection with long-distance resource acquisition is possible, but highly speculative at present.
Spatial resistivity profiling of multilayer capacitors as a function of furnace atmosphere

The research preformed was designed to discover what specific aspects of furnace control or sintering atmospheres cause a multilayer capacitor (MLC) to degrade and fail under typical usage conditions and typical HALT conditions. Reliability problems were assumed to relate to furnace atmosphere and burn-in testing. MgTiO/sub 3/ and commercial X7R BaTiO/sub 3/ MLCs were used in this study. These samples were initially examined in their as received state using a semiconductor probing station adapted for use as a DC high resistivity profiling device. The samples were then annealed in various partial pressures of oxygen (PO/sub 2/) in an effort to alter oxygen vacancy concentration and change the density of charge carriers in the samples. Using DC profiling, it was found that there was a decrease in the insulation resistance of the dielectric material as samples were reduced in low PO/sub 2/ atmospheres. This was thought to be a possible source of life test failure. After reduction the BaTiO/sub 3/ MLCs were re-oxidized in air for varying lengths of time and then profiled before HALT tested.
Ocular Effects of Behavior Management Medications

Background: Medications are often recommended for patients to control unwanted behaviors. Treatment with prescription drugs for autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and acquired brain injury (ABI) has benefits and side effects. Gains may be made in attention and mental focus while accommodation and eye tracking may be compromised. Benefits versus side effects must be considered when managing these conditions with drugs. Case Summary: A five-year-old girl presented for preschool evaluation. She destroyed the tape in the audio tape player in the waiting room, broke several legos, tore pages from the children’s books and magazines and spilled a soda before being called back for her exam. History was positive for Rett’s syndrome. No medications were taken. All examination parameters were within normal limits. The following year she returned complaining of difficulty reading and focusing at near. She managed to sit quietly in the waiting area and play with a puzzle before her eye exam began. The history revealed that she had started taking Prozac orally during the school year. Her mother reported that she read constantly. Reading material was constantly held close. She became aggressive when challenged to move it away. Exam findings showed distance visual acuities at 20/20 and near acuities reduced to 20/50. Accommodative testing showed reduced amplitude. A near prescription of +1.00 OU was recommended to assist in her reading focus. Conclusion: Behavior modifying medications were used to help this child and manage behavior in the classroom. Reduced accommodation is a known side effect of many commonly used drugs in the treatment of disorders such as ASD, ADHD, and ABI. Awareness of these medications and their side effects is warranted by eye care providers.