cssi/SciSciGPT-SciSciNet huggingface dataset:
Performance and acceptance testing of SPECT/CT

2240 Objectives Installation of a SPECT/CT system requires shielding and acceptance tests to ensure proper performance. This study was initiated to evaluate shielding requirements and critical procedures involved in the acceptance testing process. Methods Calculations were performed to ensure that the radiation field from the CT was in accordance with ALARA’s established maximum permissible dose for restricted radiation areas (10mR) and public areas (2mR). Analysis of Computed Tomography Dose Index Volume (CTDIv) for Adult Head, Adult Chest Exposure, and Pediatric Body Exposure, Phantom and Scanner Alignment, CT Number Calibration, Slice Thickness, Low Contrast Resolution, Uniformity, Noise, and High Contrast Spatial Resolution were performed by using a phantom and set CT parameters. The SPECT was tested by using intrinsic and extrinsic methods. Results The radiation field from the CT was calculated at 1 mR. The CTDIv’s for specified CT scans were: 56.2 mGy, 11.5 mGy, and 11.9 mGy, respectively. Observations for phantom and scanner alignment were visually acceptable. CT number calibration and slice thickness were -90.0, -3.1, 127.0, 880.9, -992.5 for polyethylene, water, acrylic, bone, and air, respectively. Low contrast resolution was 6.0 HU. Uniformity and noise were visually acceptable. High contrast spatial resolution was calculated at 7 lp/cm. All measurements passed the ACR and AAPM reccomendations. Performance and acceptance testing of the intrinsic and extrinsic aspects of the SPECT was successfully completed according to manufacturer specifications and NEMA criteria. Conclusions The SPECT/CT system is functioning optimally in accurate detection and system configuration, ensuring proper performance. A maintenance program is needed for ongoing quality control and calibration of the scanner.
Detecting lung overdistention in newborns treated with high-frequency oscillatory ventilation

Positive airway pressure (Paw) during high-frequency oscillatory ventilation (HFOV) increases lung volume and can lead to lung overdistention with potentially serious adverse effects. To date, no m...
Simultaneous Rapid Saline Flush to Correct Catheter Malposition: A Clinical Overview

Abstract Central venous catheters and peripherally inserted central catheters are fundamental in the delivery of pharmacologic and nutrition therapies to patient populations, including individuals with cancer. Malposition and migration of these catheters outside of the superior or inferior vena cava can contribute to delays in therapy as individuals await repositioning, and in some cases replacement of the catheter. Traditional repositioning using overwire or interventional radiology techniques can be costly and may delay care. The placement and management of these catheters has increasingly become the domain of specially trained vascular access nurses. A team of specially trained vascular access nurses, in collaboration with interventional radiologists at a National Cancer Institute-designated comprehensive cancer center developed a procedure for catheter repositioning using a simultaneous rapid saline flush technique (SRSFT). We present this procedure, along with implications for cost and clinical outcomes. Clinical outcomes suggest that 68% of catheters have been successfully repositioned using this technique with no adverse events associated with the procedure noted to date. In addition, the use of the SRSFT represents a cost savings of up to 90% compared with traditional repositioning procedures. The SRSFT is identified as safe, timely, cost-conscious, and therapeutically effective, although further research is needed to formally evaluate the efficacy of repositioning using this technique compared with overwire and interventional-radiology-guided repositioning, including complications and quality outcomes.
Oncolytic viral therapy for human colorectal cancer and liver metastases using a multi-mutated herpes simplex virus type-1 (G207)

G207 is a multi-mutated, replication-competent type-1 herpes simplex virus designed to target, infect, and lyse neurological tumors. This study examines the feasibility of using G207 in the treatment of human colorectal cancer and defines the biological determinants of its antitumor efficacy. This virus was tested on five human colorectal cancer cell lines in vitro to determine efficacy of infection and tumor cell kill. These results were correlated to measures of tumor cell proliferation. In vivo testing was performed through direct injections of G207 into xenografts of human colorectal cancer tumors grown in flanks of athymic rats. To evaluate an alternate method of administration, hepatic portal vein infusion of G207 was performed in a syngeneic model of liver metastases in Buffalo rats. Among the five cell lines tested, infection rates ranged between 10% and 90%, which correlated directly with S-phase fraction (8.6%-36.6%) and was proportional to response to G207 therapy in vitro (1%-93%). Direct injection of G207 into nude rat flank tumors suppressed tumor growth significantly vs. control (0.58 +/- 0.60 cm(3) vs. 9.16 +/- 3.70 cm(3), P<0. 0001). In vivo tumor suppression correlated with in vitro effect. In the syngeneic liver tumor model, portal infusion resulted in significant reduction in number of liver nodules (13 +/- 10 nodules in G207-treated livers vs. 80 +/- 30 nodules in control livers, P<0.05). G207 infects and kills human colorectal cancer cells efficiently. In vitro cytotoxicity assay and tumor S-phase fraction can be used to predict response to treatment in vivo. This antineoplastic agent can be delivered effectively by both direct tumor injection and regional vascular infusion. G207 should be investigated further as therapy for colorectal cancer and liver metastases.
Revisit to Kaposi's varicelliform eruption: role of IL-4.

Background. Kaposi's varicelliform eruption (KVE) is characterized by disseminated cutaneous eruptions usually caused by infection with herpes simplex virus (HSV). Kaposi's varicelliform eruption is commonly observed among patients with atopic dermatitis (AD). Why AD patients are prone to HSV infections is still an enigma. Recent findings suggest that an increased number of IL-4-secreting cells can be cloned from lesions of AD. Because IL-4 is a known Th1 cell inhibitor, theoretically, by inhibiting the Th1 cells, it could downregulate the immune response against HSV. In this study, we have evaluated the role of IL-4 on HSV replication. Methods. Peripheral blood mononuclear cells (PBMC) from 10 HSV seronegative and five seropositive healthy individuals were stimulated with PHA, recall antigen (tetanus toxoid), and HSV antigen in combination with IL-4 and anti-IL-4. Supernatants were assessed for interferon (IFN) gamma, IL-4 by enzyme-linked immunosorbent assay (ELISA), and for anti-HSV effect. Anti-HSV effect was assessed by measuring inhibition of the cytopathic effect (CPE) of HSV on a Vero cell line. Results. Both seropositive and seronegative groups showed significant inhibition of IFN-gamma secretion with addition of IL-4 (P < .001, Wilcoxon rank sum test) and this effect could be neutralized by anti-IL-4. There was a direct relationship between the IFN-gamma concentration and the HSV cytopathic effect and an inverse relationship between IL-4 concentration and HSV CPE. Conclusions. This study provides evidence that IL-4 can enhance HSV infection. Therefore, it is conceivable that patients with conditions of increased activity of IL-4, as in ad, would be prone to extensive forms of HSV infection.
Gender differences in social anxiety disorder: results from the national epidemiologic sample on alcohol and related conditions.

Abstract This study examined gender differences among persons with lifetime social anxiety disorder (SAD). Data were derived from the National Epidemiologic Survey on Alcohol and Related Conditions ( n = 43,093), a survey of a representative community sample of the United States adult population. Diagnoses of psychiatric disorders were based on the Alcohol Use Disorder and Associated Disabilities Interview Schedule—DSM-IV Version. The lifetime prevalence of SAD was 4.20% for men and 5.67% for women. Among respondents with lifetime SAD, women reported more lifetime social fears and internalizing disorders and were more likely to have received pharmacological treatment for SAD, whereas men were more likely to fear dating, have externalizing disorders, and use alcohol and illicit drugs to relieve symptoms of SAD. Recognizing these differences in clinical symptoms and treatment-seeking of men and women with SAD may be important for optimizing screening strategies and enhancing treatment efficacy for SAD.
First Principles and Thermodynamic Modeling of CdS Surfaces and Nanorods

Following recent reports of the successful low-temperature synthesis of high quality and single-crystal CdS quantum nanostructures, attention has turned toward identifying the critical factors affecting the preferred shape and surface structure of these important nanomaterials. Presented here are the results of first principles calculations, examining the surface structure, surface energy, and isotropic surface stress of clean reconstructed CdS low index surfaces. These results have been used as input for a shape-dependent thermodynamic model to determine the equilibrium shapes and aspect ratio of CdS nanostructures over a range of experimentally relevant sizes. The predicted shape is also directly compared with experimental results for CdS nanorods prepared using hydrothermal synthesis methods.
Localization of RNA Synthesis in Interphase Nuclei of Allium Cepa

ABSTRACTAnalysis of electron microscope radioautographs indicates that interphase nuclei of onion seedling rootlet meristem utilize uridine-H3 so that label is shown more often over electron dense than electron diffuse chromatin even when short incubation periods with no chase are employed. The label is not present over chromatin or nucleolus when sections are exposed to RNAse. In some mammalian cells in culture and in the microspore of Trillium erectum it has been shown that RNA synthesis occurs to a greater extent over diffuse chromatin than dense and that label tends to shift to dense chromatin with long exposure to isotope or during cold chase periods. In other cases, RNA has been found to be synthesized at the edges of dense chromatin as well as in interchromosomal spaces. The possibility that onion seedling rootlet nuclei are exceptional in that their dense chromatin can synthesize RNA is supported not only by the study described here but by some other unusual cases in which heterochromatin has been...
Glucose tolerance and lipid‐lipoprotein levels in middle‐aged powerlifters

The purpose of this study was to obtain information regarding the effects of a form of strength training (powerlifting) on certain coronary artery disease (CAD) risk factors in middle-aged men. The risk factors studied were the plasma lipid-lipoprotein profile, glucose tolerance and plasma insulin levels, all of which have been shown to be favourably influenced by endurance training in middle-aged and older men. Five elite powerlifters (52 +/- 9 years) were compared to distance runners and sedentary controls of similar age with whom they were matched in terms of body fatness as estimated from skin-fold thickness measurements. The powerlifters had a significantly (P less than 0.01) lower HDL cholesterol (HDL-C) level (34 +/- 4 mg/100 ml) than the sedentary controls (48 +/- 12 mg/100 ml) and runners (54 +/- 8 mg/100 ml). The total cholesterol to HDL-C ratio, a good indicator of CAD risk, was 41% higher in the powerlifters than in the controls, and 57% higher than in the runners (both P less than 0.01). The total area under the glucose tolerance curve during an oral glucose tolerance test (OGTT) for the powerlifters was 74% higher than for the sedentary controls (P less than 0.05) and 229% higher than for runners (P less than 0.01). Similarly, the total area under the OGTT insulin curve for the powerlifters was 68% higher than for sedentary controls and 332% higher than for the runners (P less than 0.001). These findings suggest that middle-aged powerlifters, in marked contrast to endurance athletes, have an increased risk of developing CAD.
Characterization of the juvenile hormone esterases during embryogenesis of the house cricket, Acheta domesticus

Summary Juvenile hormone (JH) and α-naphthyl acetate (α-NA) esterase activity was measured on a daily basis during embryogenesis of the house cricket, Acheta domesticus. In eggs dissected from the lateral oviducts and embryos through blastokinesis, there were elevated levels of nonspecific JH esterase activity. The JH esterase activity could not be resolved from the α-NA esterase activity by gel filtration chromatography and the metabolism of both substrates was inhibited equally by 0,0-diisopropyl phosphorofluoridate (DFP). From blastokinesis through egg hatch, the JH esterase activity was maintained at relatively low levels and was resolved from the α-NA esterase activity by gel filtration. The α-NA esterase activity was inhibited by DFP while the JH esterase activity was relatively unaffected. Low JH titers in eggs must be maintained through blastokinesis for normal development. Elevated JH esterase activity in eggs during this period appears to have a functional role in the metabolism of maternal JH i...
Ultrafast ionization and fragmentation of molecular silane

The ionization and fragmentation of molecular silane is examined here with laser intensities ranging between $7\ifmmode\times\else\texttimes\fi{}{10}^{12}$ and $1\ifmmode\times\else\texttimes\fi{}{10}^{15}$ W/cm${}^{2}$ at $624$ nm. The ionization potential of silane determined using both multiphoton ionization (MPI) and tunneling ionization (TI) models agrees with the vertical ionization potential of the molecule. In addition, the application of the tunneling ionization model is extended here to the fragments of silane to determine their appearance potentials. MPI values for SiH${}_{3}{}^{+}$, SiH${}_{2}{}^{+}$, SiH${}^{+}$, Si${}^{+}$, as well as ${\mathrm{H}}_{2}{}^{+}$ and ${\mathrm{H}}^{+}$ are consistent with vertical potentials, whereas the TI measurements are found to be in accord with adiabatic potentials. The tunneling appearance potentials observed for the fragments ${\mathrm{H}}_{2}{}^{+}$ and ${\mathrm{H}}^{+}$ are lower than reported for other techniques. In fact, the appearance potential measurements for these species resulting from silane are lower than their ionization potentials. The fragmentation rate of silane is determined to be nearly $20$ times larger than the ionization rate. The main precursor for producing amorphous silicon ($a$-Si:H) thin films, SiH${}_{3}{}^{+}$ is the dominant fragmentation product making up roughly a third of the total ion yield, a substantial increase from other techniques.
Hard Lessons in Rutebeuf’s Lives of Mary of Egypt and Elizabeth of hungary

While Rutebeuf’s Lives of Mary of Egypt (1262) and Elizabeth of Hungary (1264-5) depict diverging paradigms of religious conversion, his frequent use of the words endureir, dureir, and dur, underscores the commonality of the saints’ metamorphoses. Both Mary and Elizabeth become exemplary penitents; both embrace radical models of lay religiosity. The saints’ conversions are practically inimitable and paradoxically undesirable for medieval audiences. Rutebeuf transforms his saintly subjects into objects: hard lessons and relics. His hagiographic poems negotiate between the desire for spiritual renewal and the conservative tendencies of the medieval church. The poems themselves seem calcified; their exempla of extraordinary holiness ultimately advocate a softer conversion for audiences.
Analysis of Stress Response to Various Strain-Paths in Axial-Torsional Deformation of Metals

The stress response to various axial-torsional strain paths is discussed. The modified endochronic plasticity theory, which is formulated based on plastic-strain is used for theoretical analysis. In a sensitivity study, it is shown that a substantial amount of change in the stress response is induced by a small perturbation on the plastic-strain path. Of this change a significant amount is due to perturbation in the direction of the plastic-strain path. Several stepwise strain paths, both total-strain and plastic-strain paths, are also included in the investigation. It has been found that, when the number of steps is increased to infinity such that the strain path converges to a straight line corresponding to an in-phase path, the stress response to such a path is wildly fluctuating in the stress space if the path is a plastic-strain path, and the stress response converges to that of the in-phase path if the path is a total-strain path.
Being Female in the Eighties and Nineties: Conflicts between New Opportunities and Traditional Expectations among White, Middle Class, Heterosexual College Women.

The eighties and nineties would appear to be an ideal time for a young woman to come of age in American society. Legal barriers to opportunity have been virtually eliminated, and attitudes toward women seem to reflect greater cultural appreciation of their abilities and needs. However, there are indications that females are presented with conflicting images which nurture new career-related expectations while simultaneously stressing traditional expressions of femininity, especially marriage and motherhood. The research in this article explores the dynamics of conflicting demands on young women through a survey conducted at a small liberal arts college with students who are predominantly white and heterosexual, from middle and upper income families. (Only three percent of the students are from minority backgrounds.) Issues explored involve spousal obligations, salary differentials, marriage-career aspirations, responsibilities toward young children, and perceived degree of liberalism-conservatism pertaining to the place of women in society. The article concludes with a focus on the dilemma posed by new opportunities through structural change and the coexistence of cultural lag in the form of traditional norms of femininity.
Social stratification and the digital divide

Whereas recent studies show that the size of the Digital Divide has been shrinking for many groups, this article explores whether social-economic factors explain the racial, geographic, and gender divides. Rural, minority, and female respondents were less likely to have home computers or to be connected to the Internet. Controlling for socioeconomic variables, the effects of rural residence and gender disappeared but African Americans were still less likely to have home computers or Internet access. When public Internet access was examined, rural residence and gender had no effect but African Americans were more likely to know of public facilities in their community even when socioeconomic variables were controlled. Future research needs to better understand the implications of different ways of using new technology (i.e., public vs. private access) and determine if digital technology deepens socioeconomic chasms or provides new opportunities.
Nouns Mark Category Relations: Toddlers' and Preschoolers' Word‐Learning Biases

Recent research suggests that preschool children approach the task of word learning equipped with implicit biases that lead them to prefer some possible meanings over others. The noun-category bias proposes that children favor category relations when interpreting the meaning of novel nouns. In the series of experiments reported here, we develop a stringent test of the noun-category bias and reveal that it is present in children as young as 2 years of age. In each experiment, children participated in a 5-item match-to-sample task. Children were presented with a target item (e.g., a cow) and 4 choices, 2 of which belonged to the same superordinate category as the target (e.g., a fox and a zebra) and 2 of which were thematically related to the target (e.g., milk and a barn). In Experiment 1 we demonstrate that novel nouns prompt preschool children to attend to superordinate-level category relations, even in the presence of multiple thematic alternatives. In Experiment 2, we ascertain that the bias is specific to nouns; novel adjectives do not highlight superordinate category relations. In Experiment 3, we demonstrate the noun-category bias in 2-year-olds. The nature and utility of the noun-category bias are discussed.
Effect of polymer mixtures on the performance of PDLC films

Generally one type of polymer is used in the construction of polymer dispersed liquid crystal (PDLC) films. The authors tested the effect of incorporating an additional fluoropolymer in varying percentages on the electro-optic performance of PDLC films based on poly(methyl methacrylate). Compared to samples made from a single polymer, several correlations are noted, including a decrease in liquid crystal fall-time, an increase in rise-time, and an increase in the threshold voltage (Vt).
Vocal tract area functions from two point acoustic measurements with formant frequency constraints

A formulation is presented by which the cross-sectional areas of the vocal tract can be computed from the pressure spectrum. The pressure spectrum is the magnitude squared of the transfer function relating acoustic pressure at the glottis to pressure measured in the acoustic radiation field beyond the lips. Two correction parameters are determined using an iterative procedure. One parameter relates to the absolute scaling of the vocal tract areas; the other parameter is the area of the vocal tract at its driving point. This formulation is not robust when applied to a vocal tract with wall losses. The problem results from the effect of wall losses on the amplitudes of pressure spectrum peaks. A correction factor is applied which constrains the formant frequencies of the estimated vocal tract shape to match observed formant frequencies. This correction factor is obtained by a noniterative procedure. The resulting area function estimation procedure is applied to acoustic data computed from the Fant area functions. The area function estimates show the procedure to be robust in the case of lossy vocal tract walls and a free space radiation load.
Recapitulation of an Ion Channel IV Curve Using Frequency Components

INTRODUCTION: Presently, there are no established methods to measure multiple ion channel types simultaneously and decompose the measured current into portions attributable to each channel type. This study demonstrates how impedance spectroscopy may be used to identify specific frequencies that highly correlate with the steady state current amplitude measured during voltage clamp experiments. The method involves inserting a noise function containing specific frequencies into the voltage step protocol. In the work presented, a model cell is used to demonstrate that no high correlations are introduced by the voltage clamp circuitry, and also that the noise function itself does not introduce any high correlations when no ion channels are present. This validation is necessary before the technique can be applied to preparations containing ion channels. The purpose of the protocol presented is to demonstrate how to characterize the frequency response of a single ion channel type to a noise function. Once specific frequencies have been identified in an individual channel type, they can be used to reproduce the steady state current voltage (IV) curve. Frequencies that highly correlate with one channel type and minimally correlate with other channel types may then be used to estimate the current contribution of multiple channel types measured simultaneously. METHODS: Voltage clamp measurements were performed on a model cell using a standard voltage step protocol (-150 to +50 mV, 5mV steps). Noise functions containing equal magnitudes of 1-15 kHz frequencies (zero to peak amplitudes: 50 or 100mV) were inserted into each voltage step. The real component of the Fast Fourier transform (FFT) of the output signal was calculated with and without noise for each step potential. The magnitude of each frequency as a function of voltage step was correlated with the current amplitude at the corresponding voltages. RESULTS AND CONCLUSIONS: In the absence of noise (control), magnitudes of all frequencies except the DC component correlated poorly (|R|<0.5) with the IV curve, whereas the DC component had a correlation coefficient greater than 0.999 in all measurements. The quality of correlation between individual frequencies and the IV curve did not change when a noise function was added to the voltage step protocol. Likewise, increasing the amplitude of the noise function also did not increase the correlation. Control measurements demonstrate that the voltage clamp circuitry by itself does not cause any frequencies above 0 Hz to highly correlate with the steady-state IV curve. Likewise, measurements in the presence of the noise function demonstrate that the noise function does not cause any frequencies above 0 Hz to correlate with the steady-state IV curve when no ion channels are present. Based on this verification, the method can now be applied to preparations containing a single ion channel type with the intent of identifying frequencies whose amplitudes correlate specifically with that channel type.
Proper use of equations of state for compositional reservoir simulation

Equation of state (EOS) compositional reservoir simulation is an accurate and powerful means to model complicated phase and flow behavior involved in the displacement of oil and gas in porous media. The use of EOS simulation becomes even more effective when the process involves solvent injection for miscible or near-miscible displacement of crude oil in reservoirs. The current trend of combining the simulation of reservoirs and surface facilities increases the demand for use of EOS compositional models. One key to proper use of compositional simulators is development of an EOS for describing the phase behavior of the fluids. This paper is a summary of experiences and developments in the use of EOS's for compositional reservoir simulation studies. The reader is reffered to the recent monograph by Whitson and Brule for a more complete treatment of the volumetric and phase behavior of petroleum fluids and the use of EOS's to model these fluids.
Pulsed EPR study of amino acid and tetrahydropterin binding in a tyrosine hydroxylase nitric oxide complex: evidence for substrate rearrangements in the formation of the oxygen-reactive complex.

Tyrosine hydroxylase is a nonheme iron enzyme found in the nervous system that catalyzes the hydroxylation of tyrosine to form l-3,4-dihydroxyphenylalanine, the rate-limiting step in the biosynthesis of the catecholamine neurotransmitters. Catalysis requires the binding of three substrates: tyrosine, tetrahydrobiopterin, and molecular oxygen. We have used nitric oxide as an O2 surrogate to poise Fe(II) at the catalytic site in an S = 3/2, {FeNO}7 form amenable to EPR spectroscopy. 2H-electron spin echo envelope modulation was then used to measure the distance and orientation of specifically deuterated substrate tyrosine and cofactor 6-methyltetrahydropterin with respect to the magnetic axes of the {FeNO}7 paramagnetic center. Our results show that the addition of tyrosine triggers a conformational change in the enzyme that reduces the distance from the {FeNO}7 center to the closest deuteron on 6,7-2H-6-methyltetrahydropterin from >5.9 A to 4.4 ± 0.2 A. Conversely, the addition of 6-methyltetrahydropterin ...
Correlation expansions for CDO pricing

This paper develops numerical approximations for pricing collateralized debt obligations (CDOs) and other portfolio credit derivatives in the multifactor Normal Copula model. A key aspect of pricing portfolio credit derivatives is capturing dependence between the defaults of the elements of the portfolio. But, compared with an independent-obligor model, pricing in a model with correlated defaults is more challenging. Our approach strikes a balance by reducing the problem of pricing in a model with correlated defaults to calculations involving only independent defaults. We develop approximations based on power series expansions in a parameter that scales the underlying correlations. These expansions express a CDO tranche price in a multifactor model as a series of prices in independent-obligor models, which are easy to compute. The approach builds on a classical approximation for multivariate Gaussian probabilities; we introduce an alternative representation that greatly reduces the number of terms required to evaluate the coefficients in the expansion. We also apply this method to the underlying problem of computing joint probabilities of multivariate normal random variables for which the correlation matrix has a factor structure.
Ovulatory dysuria: a bizarre presentation of crossed non-fused ectopic kidney with extra renal pelvis.

Ectopic kidneys are a unique form of congenital anomaly that in most cases remain asymptomatic. However, depending on the location and the associated anatomical variations, they can mimic certain more common conditions, posing a challenge in differential diagnosis. They could cause secondary symptoms by virtue of their location or could falsely mimic a primary urologic problem when the etiology might be from a closely opposed adjacent structure. We present a unique case of ovulatory dysuria in a young female with a crossed non-fused ectopic kidney. The patient’s symptoms were recurrent and correlated with the ovulatory phase of the menstrual cycle. Work-up revealed the right ovary to be in close proximity to the pelvis of the ectopic kidney. Salpingo-oophrectomy was followed by complete resolution of the patient’s symptoms. The clinical manifestations, work-up, and management of symptomatic ectopic kidneys are briefly discussed in our article. Symptoms are usually attributed only by systematically excluding other causes. Surgical intervention is a last resort option only after thorough work-up with appropriate imaging studies.
Anisotropic Quantum Hall Liquids at Intermediate Magnetic Fields

The observation of significant magnetoresistance anisotropy of a two-dimensional electronic system in very clean GaAs/AlGaAs heterostructure samples in presence of moderately large perpendicular magnetic fields is a striking example of novel anisotropic behavior in the quantum Hall regime. Anisotropy appears to be the strongest at quantum Hall even-denominator filled states for filling factors ν>4 where several Landau levels are occupied. A possible explanation of these findings is due to the existence of charge density waves that are known to cause interesting phase transitions at high Landau levels. An alternative explanation of this phenomenon is to argue that the strongly correlated electronic system has stabilized in an orientationally ordered anisotropic quantum Hall liquid state. Quantum Monte Carlo calculations with a translationally invariant wave function in which rotation symmetry is broken indicate that this might be the case.
Botulinum toxin in masticatory muscles: short- and long-term effects on muscle, bone, and craniofacial function in adult rabbits

Paralysis of the masticatory muscles using botulinum toxin (BTX) is a common treatment for cosmetic reduction of the masseters as well as for conditions involving muscle spasm and pain. The effects of this treatment on mastication have not been evaluated, and claims that the treatment unloads the jaw joint and mandible have not been validated. If BTX treatment does decrease mandibular loading, osteopenia might ensue as an adverse result. Rabbits received a single dose of BTX or saline into one randomly chosen masseter muscle and were followed for 4 or 12 weeks. Masticatory muscle activity was assessed weekly, and incisor bite force elicited by stimulation of each masseter was measured periodically. At the endpoint, strain gages were installed on the neck of the mandibular condyle and on the molar area of the mandible for in vivo bone strain recording during mastication and muscle stimulation. After termination, muscles were weighed and mandibular segments were scanned with micro CT. BTX paralysis of one masseter did not alter chewing side or rate, in part because of compensation by the medial pterygoid muscle. Masseter-induced bite force was dramatically decreased. Analysis of bone strain data suggested that at 4 weeks, the mandibular condyle of the BTX-injected side was underloaded, as were both sides of the molar area. Bone quantity and quality were severely decreased specifically at these underloaded locations, especially the injection-side condylar head. At 12 weeks, most functional parameters were near their pre-injection levels, but the injected masseter still exhibited atrophy and percent bone area was still low in the condylar head. In conclusion, although the performance of mastication was only minimally harmed by BTX paralysis of the masseter, the resulting underloading was sufficient to cause notable and persistent bone loss, particularly at the temporomandibular joint.
Personal Email Management on the University Digital Desktop: User Behaviors vs. Archival Best Practices

This paper will review findings from an extensive user study which seeks to understand the ways in which individuals currently manage, interact with, and think about electronic files, particularly email. Funded by the National Historical Publications and Records Commission (NHPRC), we web-surveyed nearly 3000 faculty, staff, and administrators; and conducted personal follow-up interviews with 100 people across two universities: one public, one private. Our findings indicate that users and archivists have competing concerns. User concerns revolve around the volume of files with which they are forced to contend, leading to wasted time, improperly deleted files, confusion, and general dissatisfaction with the networked environment. Archivists, on the other hand, concerned with the preservation of digital materials, are focused on organizational issues that are often at odds with users’ daily practice.
Pressure dependence of spin-fluctuation effects in the specific heat of the heavy-fermion superconductor UPt3.

UPt/sub 3/ is a heavy-fermion superconductor with indications of coexisting long-range ferromagnetic spin fluctuations. Measurements of its specific heat at pressures of 0, 3.8, and 8.9 kbar between 0.35 and 20 K show that the spin-fluctuation terms are extremely sensitive to pressure: the linear term decreases by --25% at 8.9 kbar; the T-italic/sup 3/ and T-italic/sup 3/ lnT-italic terms decrease by factors of the order of 4. Comparison with the pressure dependence of the critical temperature suggests that the superconductivity is of a form that is e-italicn-italich-italica-italicn-italicc-italice-italicd-italic by spin fluctuations.
Implicit Algorithm for the Conservative Transonic Full-Potential Equation Using an Arbitrary Mesh

A new, implicit approximate factorization (AF) algorithm designed to solve the conservative full-potential equation for the transonic flow past arbitrary airfoils has been developed. The new algorithm uses an upwind bias of the density coefficient to provide stability in supersonic regions. This allows the simple two- and three-banded matrix form of the AF scheme to be retained over the entire flow field, even in regions of supersonic flow. A numerical transformation is used to establish an arbitrary body-fitted finite-difference mesh. Airfoil pressure distributions have been computed and are in good agreement with independent results.
DOE: Coal synffuels to dominate energy supply in 2000

Coal will be the leading source of energy in the United States by the year 2000, and it will be consumed primarily in the form of liquids and gases. Edward A. Frieman, director of energy research for the U.S. Department of Energy (DOE) offered these projections in a recent briefing to representatives of U.S. scientific and engineering societies. Renewable forms of energy (solar, biomass, and hydroelectric) are expected to reach only half of the 20% share projected in recent years.
An assessment of the archaeological applicability of faunal ageing methods based on dental wear

Mortality profiles are central to our reconstructions of past animal hunting and herding strategies. This article considers five different ageing methods based on the progressive wear of hypsodont herbivore teeth. The Quadratic Crown Height Method and the Linear Crown Height Method are based on tooth crown height. The Grant and both Payne methods are based on occlusal wear patterns. Statistical correlations and mortality profiles constructed using caprine teeth from the Anatolian Neolithic site of Catalhoyuk are used to assess the archaeological utility of each method. All of the methods are affected by uncertainties about inter- and intrapopulation variation in rates of wear, and by issues surrounding the degree of fragmentation in an assemblage. The crown height methods are biased against younger age classes. The occlusal wear-based methods suffer less from inherent age-related biases, but have significant and potentially biasing problems related to fragmentation. The degree of fragmentation in an assemblage determines which method is most appropriate for use. Comparisons of dental wear-based mortality profiles across assemblages or sites should be treated with considerable caution, unless the same method was used on all assemblages. Copyright © 2008 John Wiley & Sons, Ltd.
Dosimetry studies utilizing the Urolase right angle firing neodymium:YAG laser fiber.

Neodymium:YAG laser application was performed with the Urolase right angle laser fiber in a potato model and then in vivo in 29 canine prostates in an attempt to define dosimetry and optimal treatment parameters required to maximize tissue ablation and treatment efficacy. Depth and volume of prostatic tissue ablation for single, continuous laser applications with the Urolase fiber were measured at variable power settings from 20 to 60 watts, while holding total energy delivery constant. Peak tissue ablation was observed at 40 watts—up to a maximum of 21 mm tissue penetration in the canine model with a mode of 15 mm. The mean depth of tissue destruction at 40 watts power setting was 15.7 mm, with a mean volume of tissue ablation of 5.5 cc. The mean depth of tissue penetration at 40 watts was more than 30% greater than that observed at 60 watts, and the mean volume of tissue ablation was more than 60% greater than that observed at 60 watts. Holding the power setting constant at 40 watts, the extent of tissue ablation was measured for variable treatment times from 60 to 120 seconds. As treatment time was increased from 60 to 90 seconds, tissue ablation increased significantly. However, beyond 90 seconds of continuous laser application at 40 watts, a plateau in tissue effects was observed, with no real increase in tissue ablation between 90 and 120 seconds. Interruption or discontinuous laser application produced tissue effects which were significantly less than those observed for a single continuous 90 second laser treatment. © 1994 Wiley-Liss, inc.1
A change in the genetic code in Mycoplasma capricolum.

Mycoplasma capricolum was previously found to use UGA instead of UGG as its codon for tryptophan and to contain 75 percent A + T in its DNA. The codon change could have been due to mutational pressure to replace C + G by A + T, resulting in the replacement of UGA stop codons by UAA, change of the anticodon in tryptophan tRNA from CCA to UCA, and replacement of UGG tryptophan codons by UGA. None of these changes should have been deleterious.
Assessing Probation and Community Corrections Workers’ Attitudes Toward Sex Offenders Using the Community Attitudes Toward Sex Offenders (CATSO) Scale in a Rural State

This study explores the factor structure of the Community Attitudes Toward Sex Offenders (CATSO) scale using a population of rural corrections and probation professionals. Using Dillman's (2007) tailored design method, Internet surveys were deployed online though e-mail contacts, with a link to the survey host Web site. Data were subjected to exploratory factor analysis. Descriptive statistics clearly display this population's unique attitudes. Exploratory factor analysis reveals a 2-factor solution for the scale; this provides relatively weak support for factor structure of the original scale.
National versus ethnic identification in Africa: : modernization, colonial legacy, and the origins of territorial nationalism

Communal conflicts, civil wars, and state collapse have led many to portray the notion of African nation-states as an oxymoron. Some scholars of African politics—often referred to as second-generation modernization theorists—have argued that strong ethnic attachments across the continent resulted from rapid economic and political modernization, the very forces credited with reducing parochial ties and consolidating European nations in classic modernization theory. Others have argued that national consolidation in Africa is particularly unlikely due to high degrees of ethnic diversity, colonial rule that exacerbated that diversity, and the partition of cultural groups. Despite the ubiquity of these arguments, there has been very little comparative empirical research on territorial nationalism in Africa. Using individual-level data from sixteen countries, combined with a novel compilation of ethnic group and state characteristics, the author evaluates the observable implications of these long-respected theoretical traditions within a multilevel framework. She finds that attachment to the nation, relative to one’s ethnic group, increases with education, urbanization, and formal employment at the individual level, and with economic development at the state level—patterns more consistent with classic modernization theory than with second-generation modernization theory. Thus, if modernization in Africa does indeed intensify ethnic attachment, the impact is overwhelmed by the concurrent increase in panethnic territorial nationalism. Similarly, the results show that ethnic diversity and the partition of ethnic groups by “artificial” state borders increase, rather than decrease, the degree to which individuals identify nationally. Taken together, these results reject pessimistic expectations of African exceptionalism and instead suggest that the emergence of widespread national identification within African states is not only possible but even increasingly likely with greater economic development.
Monotone Boolean formulas can approximate monotone linear threshold functions

We show that any monotone linear threshold function on n Boolean variables can be approximated to within any constant accuracy by a monotone Boolean formula of poly(n) size.
Critical-State Transients for a Rolling 65-Degree Delta Wing

Force and moment experiments were conducted for a 65-deg delta wing undergoing ramp-and-hold and harmonic rolling motions. This extensive set of experiments isolated critical-state responses. Motions between critical states and motions crossing critical states were included. Roll-angle amplitude and the roll rate were varied. The total angle of attack and Mach number were held constant at 30 deg and 0.3, respectively. The amount of time required for the rolling moment coefficient to reach its steady-state value after the end of a ramp was quantified for numerous ramp motions. This relaxation time was a significantly large value for many of the motions, especially when the 5-deg critical state was crossed. Motion history effects were determined for motions that crossed critical states. The effect of roll rate on critical-state transients proved to be insignificant.
Bayesian inferences for receiver operating characteristic curves in the absence of a gold standard

Sensitivity and specificity are used to characterize the accuracy of a diagnostic test. Receiver operating characteristic (ROC) analysis can be used more generally to plot the sensitivity versus (1-specificity) over all possible cutoff points. We develop an ROC analysis that can be applied to diagnostic tests with and without a gold standard. Moreover, the method can be applied to multiple correlated diagnostic tests that are used on the same individual. Simulation studies were performed to assess the discrimination ability of the no-gold-standard method compared with the situation where a gold standard exists. We used the area under the ROC curve (AUC) to quantify the diagnostic accuracy of tests and the difference between AUCs to compare their accuracies. In particular, we can estimate the prevalence of disease/infection under the no-gold-standard method. The method we proposed works well in the absence of a gold standard for correlated test data. Correlation affected the width of posterior probability intervals for these differences. The proposed method was used to analyze ELISA test scores for Johne’s disease in dairy cattle.
Determination of monomethylmercury cation in sediments by vacuum distillation followed by hydride derivatization and atomic fluorescence spectrometric detection

This paper presents a method capable of quantitatively separating sub-nanogram amounts of monomethylmercury cation (MeHg+) and dimethylmercury from sediments by vacuum distillation at 40 °C and 6 μm Hg pressure followed by hydride derivatization and atomic fluorescence spectrometric detection. Concentrations of MeHg+ in Great Bay Estuarine sediments ranged from 2.2 to 7.3 ng g−1 (dry weight) with a 4.7 ng g−1 average for samples taken over nine weeks of the 1996 summer. The RSD for replicate determinations of a homogenized estuarine sediment is typically less than 6%. The detection limit for the routine determinations on MeHg+ is 0.2 ng g−1 dry weight of sediment. We validated the method by determining MeHg+ concentration in reference sediment S-19, by confirming our method against an established extraction method, and by recovering 85% of 10 ng MeHgCl spiked into estuarine sediments. This paper also includes significant improvements in the hydride derivatization method for mercury compounds relative to previous work with respect to faster analysis time and lower detection limits. © 1997 John Wiley & Sons, Ltd.
Screening for High-Affinity Ligands to the Src SH2 Domain Using Capillary Isoelectric Focusing-Electrospray Ionization Ion Trap Mass Spectrometry

A solution-based microscale approach for determination of high-affinity noncovalent complexes from mixtures of compounds is presented, based on capillary isoelectric focusing coupled on-line with electrospray ionization ion trap mass spectrometry. The studies are performed using the src homology 2 domain and tyrosine-phosphorylated peptide ligands as a model system. Tight complexes are formed in solution, preconcentrated up to 2 orders of magnitude and separated on the basis of their isoelectric points. The complexes are then dissociated in the mass spectrometer and the freed ligands identified. Picomole or less amounts of protein reagent are consumed per experiment. Structural information for the ligands involved in tight complex formation may be obtained using the MSn capabilities of the ion trap. The methodology can potentially be used to screen rapidly combinatorial mixtures of compounds for high-affinity ligands.
The hydraulic conductivity of rabbit ciliary epithelium in vitro.

Abstract The rate of fluid movement across rabbit ciliary body in vitro has been measured as a function of applied hydrostatic pressure. Previous studies from other laboratories carried out with the ciliary body clamped between two half chambers have yielded a value of 4600 ± 600 μm/sec. We have presently reproduced those results by using a similar mounting procedure. On the other hand, however, we report the development of a technique for edge-damage-free mounting of the ciliary body with which the tissue is not clamped and tissue glue is employed in order to achieve a proper seal. With this last procedure, the values thus obtained for the hydraulic conductivity were much lower than the previous ones, namely, 210 μm/sec for pressure applied on the stromal side of the ciliary epithelium (pressure range: 0–10 cm H 2 O, n = 13; T = 37°C), or 109 μm/sec (pressure difference range: 0–31 cm H 2 O) for pressure applied from the aqueous side. We conclude that the notion of aqueous production by ultrafiltration cannot be supported by the present results.