cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 1381: The effect of proteasome inhibitor velcade on tumor microenvironment

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC It has been reported that the therapeutic effect of the proteasome inhibitor Velcade is due to its selective interference in the hypoxia pathway. We studied the effect of Velcade on tumor microenvironment and examined the underlying molecular mechanisms. We have generated a human colorectal cancer xenograft model (#C53) in which the hypoxia-inducible dual reporter fusion gene (HSV1-TK and eGFP) was under the control of hypoxia-response-element (HRE). In vitro, #C53 cells were treated with Velcade in normoxic and hypoxic conditions, and the following assays were performed in comparison with controls: eGFP (flow cytometry), CA9 (western blot), VEGF (ELISA), and TK activity (trapping of the marker substrate 14C-FIAU). In vivo, #C53 xenografts were treated with Velcade and various assays performed, including a) Dynamic contrast-enhanced (DCE) MRI pre and post treatment; b) dual hypoxia marker (pimonidazole and EF5) administration pre and post treatment; c) fluorescence microscopy of Hoechst 33342 (perfusion), eGFP, HIF-1α, and CA9; and d) plasma VEGF level (ELISA), Where applicable data from control and treated tumors were compared. Our results showed that in both in vitro and in vivo experiments Velcade treatment increased the level of HIF1α, but decreased those of hypoxia-induced eGFP, TK, CA9 and VEGF. Interestingly, in the dual hypoxia marker study there were significant EF5-positive regions that did not co-localize with pimonidazole-positive regions, suggesting de novo hypoxia and perhaps another novel effect of Velcade on tumor microvasculature. Consistent with these results, DCE MRI demonstrated decrease global tumor blood flow with Velcade treatment. Our data suggest that Velcade suppresses the hypoxia response by disrupting the HIF1 transcriptional activity. In addition, our results suggest a novel function of Velcade in modifying the tumor microenvironment and decreasing tumor perfusion as noninvasively detected by DCE MRI. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1381.
Katherine Kendall: A Social Work Institution:

Katherine Kendall has been one of the leaders in social work education and especially international social welfare for more than 50 years. She was a founder of the Council of Social Work Education ...
Outcomes of Delayed Chest Closure After Bilateral Lung Transplantation

Background Delayed chest closure (DCC) may be used after bilateral lung transplantation when significant bleeding/coagulopathy or severe pulmonary edema exists. Primary chest closure (PCC) in these patients can lead to heart and lung compression causing cardiopulmonary instability. The purpose of this study is to describe factors associated with DCC and evaluate outcomes after DCC. Methods We performed a retrospective review of all patients undergoing bilateral lung transplantation between September 2003 and March 2005. Statistical significance was determined by two-tailed t test or Fisher's exact test. Results Twenty-eight bilateral lung transplantations were performed. Indication for transplant was chronic obstructive pulmonary disease (13), pulmonary fibrosis (5), cystic fibrosis (5), sarcoidosis (3), and pulmonary hypertension (1). Seven patients (25%) required DCC. Mean time to DCC was 5.3 days. Six patients (86%) with DCC required tracheostomy versus 4 patients (20%) with PCC ( p = 0.003). Mean days to discharge was 44 in the DCC group and 21 in the PCC group ( p = 0.03). Thirty-day survival was 100% in the DCC group and 95% in the PCC group ( p = 1.0). There were no wound infections in either group, and 1 patient in the PCC group had sternal nonunion. Delayed chest closure was associated with cardiopulmonary bypass use ( p = 0.006), cardiopulmonary bypass time longer than mean cardiopulmonary bypass time (mean, 224 minutes; p = 0.04), PaO 2 /FiO 2 less than mean + 1 SD (value = 4.63, p = 0.0002), evidence of moderate/severe reperfusion injury on chest radiograph ( p = 0.0002), and PaO 2 /FiO 2 less than mean plus moderate/severe reperfusion injury on chest radiograph ( p = 0.002). Conclusions Cardiopulmonary bypass use, prolonged cardiopulmonary bypass time, and significant reperfusion injury, as determined by chest radiograph and a low PaO 2 /FiO 2 ratio were all associated with an increased incidence of DCC in our bilateral lung transplantation patients. These patients had no wound infections or sternal complications, and although they had longer hospital stays than PCC patients, DCC did not affect operative survival. Delayed chest closure can be employed safely, when necessary, after bilateral lung transplantation with outcomes similar to patients with PCC.
Investigating mixing in a multi-dimensional rotary mixer: Experiments and simulations

Abstract Mixing is an important but poorly understood aspect in petrochemical, food, ceramics, fertilizer and pharmaceutical processing and manufacturing. Segregation and mixing phenomenon occur in most systems of powdered or granular solids and have a significant influence on their behavior. Deliberate mixing of granular solids is an essential operation in the production of industrial powder products usually constituted from different ingredients. The knowledge of particle flow and mixing in a blender is critical to optimize the design and operation. Since performance of the product depends on blend homogeneity, the consequence of variability can be detrimental. A common approach to powder mixing is to use a tumbling blender, which is essentially a hollow vessel horizontally attached to a rotating shaft. This single axis rotary blender is one of the most common batch mixers among in industry, and finds use in myriad of application as dryers, kilns, coaters, mills and granulators. In most of the rotary mixers, the radial convection is faster than axial dispersion transport. This slow dispersive process hinders mixing performance in many blending, drying and coating applications. A double cone mixer is designed and fabricated which rotates around two axes, causing axial mixing competitive to its radial counterpart. Discrete Element Method (DEM) based numerical model is developed to simulate the granular flow within the mixer. Digitally recorded mixing states from experiments are used to fine-tune the numerical model. Discrete pocket samplers are also used in the experiments to quantify the characteristics of mixing. A parametric study of the effect of initial loading, particle size, fill ratio, vessel speeds, on the granular mixing is investigated by experiments and numerical simulation. Incorporation of dual axis rotation enhances axial mixing by 60 to 90% in comparison to single axis rotation. Mixing is achieved faster with front–back initial loading than with side–side loading. Particle size and fill level are found to have no significant effect on mixing characteristics.
Conceptual models of upper‐level frontogenesis in south‐westerly and north‐westerly flow

The conceptual model proposed by Shapiro as it is applied to the evolution of an upper-level frontal zone within a baroclinic wave is reviewed and its limitations are investigated through previous literature and two casestudies presented in this paper. the early stages in the evolutions of these two cases are used to examine specific limitations of this conceptual model: (1) upper-level frontogenesis in south-westerly flow that evolves from a state of equivalent barotropy to a state of cold advection along the front, and (2) upper-level frontogenesis in northwesterly flow with along-front variation in the sign of the thermal advection, such that warm advection occurs upstream of cold advection in the thermal trough. Vector-frontogenesis diagnostics for the Lagrangian rate of change of the magnitude and direction of the horizontal potential-temperature gradient, including tilting due to vertical motion, are derived. These diagnostics are applied to the two cases to examine the maintenance of the potential-temperature gradient and the development of cold advection along each upper-level front. the upper-level front in south-westerly (north-westerly) flow was maintained primarily by deformation (tilting) frontogenesis, in agreement with previous research. the increasing cold advection along the upper-level front in both cases was related to an upstream vorticity maximum. For the case in south-westerly flow, the pre-existing vorticity maximum approached a downstream equivalent-barotropic upper-level front in a manner similar to an instant occlusion, resulting in cold advection along the length of the upper-level front. For the case in north-westerly flow, an intensifying vorticity maximum concentrated the cold advection in the base of the thermal trough, as warm advection developed upstream. These two cases are compared to upper-level fronts in previous literature and a climatology of upper-level fronts associated with landfalling cyclones over the eastern North Pacific Ocean. the results indicate that these two cases are typical of early evolutions of upper-level fronts that can occur in south-westerly and north-westerly flow. Therefore, a revised version of the Shapiro conceptual model is presented that represents more accurately the early evolutions exhibited in the present and previous studies.
Refractive effects in 9Be scattering and nuclear rainbow ghosts

Abstract Data for the elastic scattering of 9 Be on 12 C and 16 O at 158 MeV provide evidence of refractive effects that allow the optical potentials to be determined with little ambiguity. The real potentials are deep. Large angle data indicate dominance of negative-angle scattering from the far side of the target nucleus. The analysis also implies a residual rainbow phenomenon, contrary to what has been seen previously in heavy-ion scattering. We suggest this be called a rainbow ghost.
A possible explanation for exercise DlCO based on estimations of SAl and τh

A method is presented for predicting exercise DlCO in healthy young males from measures of resting DlCO and lung volumes. Attempts to explain the increase in DlCO with exercise, on the basis of lung volumes, have met with limited success. However, when measured lung volumes are used to estimate lung surface area (SAl) and membrane thickness (τh), and DlCO is referenced to or predicted from these estimates, the relationship appears to be an explanation for the increase in DLco during exercise.
Neural networks for structural control of a benchmark problem, active tendon system

Methodology for active structural control using neural networks has been proposed by Ghaboussi and his co-workers 1-8 in the past several years. The control algorithm in the mathematically formulated methods is replaced by a neural network controller (neuro-controller). Neuro-controllers have been developed and applied in linear and nonlinear structural control. Neuro-controllers are trained with the aid of the emulator neural networks. The emulator neural network is trained to learn the transfer function between the actuator signal and the sensor reading and it uses that past values of these quantities to predict the future values of the sensor readings. In this paper, we apply the previously developed neuro-control method in the benchmark problem of the active tendon system. The emulator neural network is developed and trained using the evaluation model given in the benchmark problem which is considered to be the true representation of the active tendon system. However, a reduced-order model has been developed and used, along with the emulator neural network, to train the neuro-controller. The evaluation model represents the three story steel frame structure, including the actuator dynamics. The absolute acceleration of the first floor and the actuator piston displacement are used as feedback. Three neuro-controllers, with different control criteria, have been developed and their performances have been evaluated with the prescribed performances indexes. The robustness of the neuro-controllers in the presence of some severe uncertainties, has also been evaluated.
Variation in patients' and pharmacists' attribution of symptoms and the relationship to patients' concern beliefs in medications.

Abstract Background The process by which symptoms are identified and characterized is related to adverse drug event reporting. Patient and pharmacist symptom attribution may differ and be related to certain patient characteristics. Objectives (1) To compare attribution of symptoms to a cause for patients and pharmacists; (2) to quantify the association between patients' concern beliefs and patient-pharmacist agreement on patients' symptom attribution to medications; and (3) to identify any associations between patients' propensity to agree with pharmacists' assessments of symptom attribution with various clinical and/or sociodemographic characteristics. Methods An Internet survey of Medicare beneficiaries was administered by Harris Interactive ® . The survey elicited information on health symptoms that subjects experienced and to whom they reported these symptoms. If subjects did not experience symptoms and did not report them, the reasons for not reporting were elicited. A clinical expert panel reported ratings about respondents' (1) likelihood of the symptom experienced being attributed to a medication and (2) probability of the symptom being attributed to the reason the patient stated. Frequencies of unreported symptoms for each reason/category were examined. Chi-square and Fisher's exact test analyses examined the variations between patients' and pharmacists' ratings of symptom attribution to medications and associations between attribution and patient sociodemographic and clinical characteristics, such as the number of medications used. Independent sample t tests examined how attributions were related to concern beliefs. Results Most patients thought their symptom(s) were the result of their disease, something other than medications or age. There was no statistically significant difference between patients' and pharmacists' symptom attribution ( χ 2 = 1.376, P = .24). Individuals whose symptom attributions differed from pharmacists were likely to have stronger concern beliefs in medication ( t = −3.03, P Conclusions Patients' concern about their medications may be related to their symptom attributions. Older adults may not consider these concerns when asked about their symptom attributions.
Predictive model of the treatment effect for patients with major depressive disorder

The model to evaluate and predict the effectiveness of treatment of the Major Depressive Disorder (MDD) was developed and estimated using MindLinc data. The clinical global impression (CGI) scale with seven categories was used to measure the patient's state. The proportional odds model was selected because of ordinal nature of the outcome. The set of predictors included i) CGI score measured at preceded visit, ii) three groups of medications (antidepressants, atypical medicine, and augmentation medicine), all categorized for appropriate number of strata (from six to nine) and their daily doses, iii) psychiatric comorbidities, iv) type of the therapy used (talk vs. medications), v) demographic variables (e.g., age group, sex), and vi) the history of the efficiency of prior treatment. More than a half of a million records with measured CGI scores and their predictors were identified in the MindLinc database and used for model estimation. The predicted model of future CGI scales was developed and evaluated for single and recurrent episodes of MDD. Significant estimates were obtained for demographic factors, history of previous SGI scales, and for comorbidity and treatment indices. The methods of causal inferences based on the inverse probability weighting approach were applied to evaluate the treatment effects. The model extensions allowing for addressing the limitations of the proportional odds model are discussed.
Comparison of a thermospheric photochemical model with Student Nitric Oxide Explorer (SNOE) observations of nitric oxide

[1] A time-dependent thermospheric model has been used to calculate the nitric oxide density in the lower thermosphere for a 935-day period, 11 March 1998 to 30 September 2000. This model uses daily values of the observed solar soft X-ray irradiance (2–7 nm) as an energy input parameter. The model does not include an energy input from auroral electron precipitation. The results of the model calculation of nitric oxide density at 110 km were compared with observations of nitric oxide density made with the Student Nitric Oxide Explorer (SNOE) for the 935-day period. At the equator the model calculations and the observations agree very well with a linear correlation coefficient of 0.876. The correlation coefficient remains high for the altitude region 107–117 km, the region where solar soft X-rays (2–7 nm) are the major source of nitric oxide production. The comparison of the model calculations with the observations as a function of latitude show that there is excess nitric oxide poleward of 30°N and S latitude particularly during the fall-winter season. We believe that the source of this excess nitric oxide is the nitric oxide that is produced in the auroral region (65°–75°N and S geomagnetic latitude) by precipitating auroral electrons. We believe that aurorally produced nitric oxide is transported equatorward by horizontal winds. At midlatitudes the excess nitric oxide decays to about half of its initial value in one day. At times of large geomagnetic storms we believe that aurorally produced nitric oxide is transported all the way to the equator by horizontal winds. The excellent correlation of the model calculations and the SNOE observations of nitric oxide at 110 km between 30°S and 30°N support the hypothesis that solar soft X-rays are the source of the variability of nitric oxide in the thermosphere at low latitudes.
Short period superlattices : is thinner better?

For type-II superlattices with spatially indirect optical transitions across the band gap, short-period superlattices are often employed. The oscillator strength of intraband transitions, from holes states confined in one layer to electron states confined in a neighboring layer, are enhanced by increasing the wave function overlap of these states through reduced superlattice period. However, there are limits to accurately controlling an epitaxially grown semiconductor superlattice structure as the number of monolayers in each layer is decreased. For InAs/GaSb type superlattices, periods of 40a or less are relevant to mid-infrared detection. Characterization and modeling results for a series of InAs/GaSb superlattices with periods ranging 50a to 20a will be presented. These results explore the break point between when thinner is better and when reducing the period no longer optimizes the superlattice optical performance.
Meaning and ontology

These are two related essays. The first, “Meaning,” defends the so‐called reference theory against current criticisms. Exemplification and the intentional tie are two subsistents. Subsistence is a mode of existence; mere possibility is another. That requires two distinctions; one among four uses of ‘possible'; one among three uses of ‘same’ in the phrase ‘the same fact'; which in turn permits an adequate account of false belief. The second essay, “Inclusion, Exemplification, and Inherence in G. E. Moore,” displays the impact of the fundamental ontological dialectic on the development of Moore's thought. His notion of nonnatural properties provides the early cue. His eventual failure to account for false belief is traced to his eventual nominalism.
Global stability for nonlinear dynamic equations with variable coefficients

We give sufficient conditions under which the trivial solution of a nonlinear dynamic equation with variable coefficients is globally asymptotically stable, for arbitrary time scales unbounded above.
Optical properties of metal surfaces from electron energy loss spectroscopy in the reflection mode

Abstract The development and evaluation of a method to determine optical constants using electron energy loss spectroscopy (EELS) in the reflection mode is reported. An empirical approach is taken in these studies in order to minimize the necessity for a-priori information concerning the sample of interest. The goal of this research is to determine optical constants of metal systems using a standard electron spectrometer and very little sample preparation. The data treatment involves isolating the loss function from the experimental EEL spectrum by (a) deconvolution of the surface plasmon contribution from the data obtained with a high-energy primary beam using data acquired with a low-energy primary beam at a grazing incidence angle, (b) minimization of the plural scattering contribution through deconvolution of a model spectrum obtained experimentally, and (c) removal of the dispersion contribution through deconvolution of a theoretical dispersion function. The complex dielectric function is obtained through a Kramers-Kronig analysis of the isolated loss function. The results for Al acquired with several primary beam energies are presented and compared to literature values. These results indicate that the proposed method is most successful for determining the dielectric function of Al when primary beam energies of 1500 eV or greater are employed. The results also suggest that dispersion effects can be minimized experimentally using primary beams of relatively high energy.
The Contribution of Dental Amalgam to Mercury in Blood

We determined the exposure to mercury from dental amalgam by comparison of blood levels of mercury before and after removal of all amalgams from ten subjects. Baseline concentrations of mercury in whole blood were measured weekly for four to 18 weeks (median = 6.6 weeks) prior to removal. All amalgams were removed in a single appointment. The subjects had an average of 14 surfaces of amalgam, seven of which were occlusal surfaces. Weekly blood sampling was continued for five to 18 weeks (median = 7.6 weeks) after the amalgams were removed. The mean baseline concentration of total mercury in whole blood of the ten subjects was 2.18 (SD = 0.90) ng Hg/mL before the amalgams were removed. The baseline mercury levels were related to the number of amalgam surfaces. The linear correlation coefficient was 0.724 with number of occlusal surfaces, and 0.433 with total number of surfaces. After removal of the amalgams, nine of the ten subjects exhibited a statistically significant decrease in blood mercury at the 95% level of confidence. The mean decrease in mercury was 1.13 (SD = 0.60) ng Hg/mL. The half-time for elimination of mercury from blood after amalgam removal was 30.2 (SD = 5.8) days. Removal of the amalgams provided an additional exposure of 1.46 (SD = 1.17) ng Hg/mL that was rapidly cleared from the blood with a half-time of 2.9 days. The daily intake of mercury from amalgam in the subjects was estimated to be at least 1.3 micrograms.
Deterministic manufacturing processes for precision optical surfaces

The Center for Optics Manufacturing is developing computer-aided manufacturing technology to produce affordable high quality spherical and non-spherical optical surfaces. Advances in MRF magnetorheological finishing), a computer-controlled deterministic finishing technology, now demonstrate a capability to polish plano, spherical, aspherical, and cylindrical optics, with round or non-round apertures, to better than 0.05 wave p-v (peak-to-valley), 5.0 a rms surface microroughness, and no subsurface damage. MRF is a paradigm shift in optics manufacturing that redefines the capabilities of the industry and will ultimately enable the affordable manufacture of any freeform optical shape.
Axially-symmetric sheared polymer network liquid crystals

An axially-symmetric sheared polymer network liquid crystal (SPNLC) device is demonstrated and its performances characterized. Through analyzing the structure of this axially-symmetric SPNLC, we constructed a 3-D model to explain the observed phenomena. The simulation results agree well with the experiment. Two potential applications of such an axially-symmetric SPNLC, namely tunable-focus negative lens and spatial polarization converter, are discussed.
A second chance

A student's excuses for not getting work done can be justifiable ones, and a teacher may experience great reward in permitting a student a second chance.
Abstract 1346: Discovery of novel MSK1 inhibitors with hybrid virtual screening and structure-based drug design

Mitogen- and stress-activated protein kinase 1 (MSK1) is a serine/threonine kinase that is involved in gene transcription regulation and pro-inflammatory cytokine stimulation. MSK1 is an attractive target for the treatment of chronic inflammatory diseases. Currently, no small molecule inhibitor has been identified that specifically targets MSK1 and only H-89 is a known inhibitor. In this study, we performed hybrid virtual screening (HVS) to identify novel small molecule inhibitors that target MSK1. For the screening, we used the active conformation of the C-terminal kinase domain of the dual kinase as the protein template. Computational screening of several well-known compound databases, including the FDA, Natural Product, ZINC all purchasable and PDB ligands databases, revealed 40 potential leads. We tested 11 lead compounds and found 5 that showed substantial in vitro inhibitory activity against MSK1. These results illustrated that our computational screening processes greatly enhanced the success rate of virtual screening. The high-performing HVS protocols were especially successful to retrieve thousands of promising new leads from millions of compounds in conjunction with structure-based drug design and then to further select true hits from the majority of high-scoring decoys. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1346. doi:10.1158/1538-7445.AM2011-1346
Microbial Reduction of CobaltIIIEDTA- in the Presence and Absence of Manganese(IV) Oxide

Codisposal of 60Co2+ and EDTA has promoted the transport of radioactive 60Co in the environment as 60CoEDTA complexes. Chemical oxidation of CoIIEDTA2- to highly stable and mobile CoIIIEDTA- by man...
Variable fractional digital delay filter on reconfigurable hardware

This paper describes a design for a variable fractional delay (VFD) FIR filter implemented on reconfigurable hardware. Fractionally delayed signals are required for several audio-based applications, including echo cancellation and musical signal analysis. Traditionally, VFD FIR filters are implemented using a complex, fixed structure based upon the order of the filter. This fixed structure restricts the range of valid fractional delay values permitted by the filter. The proposed design in this paper implements an order-scalable FIR filter, permitting fractionally delayed signals of widely varying integer sizes. This design builds upon the traditional Lagrange interpolator FIR filter using either a software-based or hardware-based Lagrange coefficient computational unit. Using today's (2012) low-cost high performance reconfigurable hardware FIR coefficients can be computed fast enough for real-time variable fractional delay applications. The resulting real-time VFD FIR filter is tested using the Xilinx System Generator toolkit as well as Xilinx ISE and ModelSim. The proposed filter was functionally verified using ModelSim and System Generator.
Growth Characteristics of Rhizoma Peanut and Nitrogen-Fertilized Bahiagrass Swards

The interaction of plant sensitivity to drought with N deficiency has been suggested as the reason grasses fail to persist under grazing when grown in association with rhizoma peanut (Arachis glabrata Benth.). To test this assumption, aboveground dry matter (DM) accumulation and relative growth rate (RGR) of ‘Florigraze‘ rhizoma peanut and ‘Pensacola’ bahiagrass (Paspalum notatum Flugge) fertilized with 0, 56, and 112 kg N ha⁻¹ were measured from March to November in 1990 and 1991. Rhizoma peanut aboveground DM accumulation was greater both years (4950 and 6100 kg ha⁻¹ 1990 and 1991, respectively) in July at the start of the summer rainy season than any N-fertilized bahiagrass treatment (640 and 1530, 1240 and 2330, and 1570 and 4490 kg ha⁻¹ in 1990 and 1991 for 0-N, 56-N, and 112-N treatments, respectively), due to higher RGR. Although the RGR of rhizoma peanut was similar to or less than that of the bahiagrass treatments for the remainder of the growing season in both years, by August 1991 only the 112-N bahiagrass treatment (5260 kg ha⁻¹) had total DM accumulation similar to rhizoma peanut (5110 kg ha⁻¹). Rhizoma peanut RGR appeared to be more sensitive to rainfall, and was positively correlated (r = 0.71) with rainfall for as long as 8 wk prior to the sample dates in the dry spring of 1990. Bahiagrass RGR showed no correlation with rainfall either year. This suggests that lack of persistence of bahiagrass in mixed swards is due to severe competition for light with rhizoma peanut in springs when moisture is adequate and to potentially increased stress due to grazing in springs when drought restricts growth of rhizoma peanut. Joint contribution of USDA-ARS and the Florida Agric. Exp. Stn. (Florida Agric. Exp. Stn. Journal Series no. R-03569).
Olfactory computations and network oscillation.

Oscillatory activity is a universal design feature of olfactory systems ([Tank et al., 1994][1]), having been demonstrated by Lord Adrian in the olfactory bulb of the hedgehog >60 years ago ([Adrian, 1942][2]). Hints as to the computational role of olfactory oscillations have only recently begun to
Competing parametric instabilities with circular symmetry

Abstract Recent experiments in circular geometry have studied the dynamics produced by two parametrically excited surface waves. There is a natural theoretical context for experiments of this type, the mode interaction between two period-doubling bifurcations in the presence of O(2) symmetry. We formulate this interaction as a map in four dimensions, and classify the primary, secondary, and tertiary bifurcations. We find that the observed amplitude oscillations can arise as a tertiary Hopf bifurcation from a mixed mode pattern provided exactly one of the primary instabilities is subcritical.
Synaptic delay: its effect on information transmission in the crayfish caudal photoreceptor system.

Upon observation of the delay time associated with synaptic transmission 2, it might be suspected that the chemical synapse acts as a noisy element and thus limits the amount of information per unit time which it can transmit. However, it is not the synaptic delay per se which constitutes noise, but rather the random variations in delay. That such fluctuations do occur can be seen in the study by Katz and Miledi 5 in which they found neuromuscular synaptic delays which fluctuated from about 0.5-2.5 msec. What Katz and Miledi measured as synaptic delay was the time interval between the preand postsynaptic membrane currents. In the present work, the term synaptic delay will indicate the total delay caused by the interposition of a synapse; this includes time lags due to transmitter release and diffusion, axonal thinning of the synaptic endings acting to slow conduction time, postsynaptic action of the transmitter, and the buildup of the postsynaptic potential towards threshold. Thus, synaptic delay as is defined here should be longer and have a greater variance than that measured by Katz and Miledi. In the present paper, experiments will be presented which determine the fluctuations in the transmission delay caused by a synaptic link located in the subesophageal ganglion of the crayfish; here, the two fibers carrying light-relative information from the caudal photoreceptor in the sixth abdominal ganglion are linked to secondary fibers in the circumesophageal commissures. After removal of all appendages, the crayfish, Procambarus clarkii (Girard), were pinned ventral side up onto a shaped paraffin dish. Two silver wire recording electrodes were applied 2 cm apart: one on the thoracic nerve cord midway between the subesophageal and first thoracic ganglia, and the other on one of the circumesophageal commissures. The exposed nerve was bathed in Van Harreveld's solution and
1/f fluctuations of the damped nonlinear oscillator equation

Abstract The 1/ f power spectrum occurs naturally for a damped nonlinear oscillator when it relaxes from high initial kinetic energy. We demonstrate this for the damped pendulum equation which, since it can describe the Josephson junction, a particle in a periodic potentials, etc., might be applicable in a number of contexts.
An Update Survey of Academic Radiologists' Clinical Productivity

Rationale and Objectives The total number of procedures and their relative value units (RVUs) were used to measure the productivity of radiologists. Besides variations in productivity due to differences in the percentage of clinical effort, baseline productivity also varies among clinical subspecialty sections. The authors' previous research used the full-time equivalent (FTE) as the unit to adjust for differences in the percentage of clinical effort and a set of adjustment factors (or calibration constants) to modify the default work RVUs according to types of procedures. These adjustments led to comparable average productivity measurements across subspecialty sections. Since 2003, radiology practice has continued to change, including the introduction of positron emission tomography/computed tomography into clinical practice, suggesting a need to update the understanding of clinical productivity and refine the authors' adjustment procedure. In this study, the authors analyzed the most recent survey of academic departments and derived updated adjustment factors for differences in workload among subspecialty sections. The results can be used to determine faculty staffing requirements and evaluate radiologists' performance. Materials and Methods A survey performed by the Society of Chairmen of Academic Radiology Departments collected data in 2006 for 1,134 radiologists in 24 departments, including 10 departments that also reported productivity in an earlier 2003 survey. These data included the numbers of procedures (represented by Current Procedural Terminology ® [CPT] codes) performed by radiologists, percentage clinical effort, subspecialty sections, and the number of clinical days. The numbers of CPT codes were converted into total work RVUs per FTE faculty member. By grouping the CPT codes into 6 prespecified examination categories, adjustment factors were created to adjust the RVUs for CPT categories to ensure that the median total adjusted work RVUs from different subspecialty sections were comparable. Results Overall, the mean clinical workload in 2006 was 9,671 examinations, a statistically significant 15% increase from 2003. The mean number of work RVUs per FTE was 7,136, a 22% increase from 2003. The adjustment factors have been modified from those presented in the authors' earlier paper, including reductions for interventional radiology, computed tomography, magnetic resonance imaging, nuclear medicine, and a new adjustment factor for "special procedures." These adjustments reduced differences in adjusted RVUs per FTE between subspecialty sections. Conclusions Clinical workload, as measured by RVUs per FTE and adjusted RVUs per FTE, is very useful for determining optimal staffing in subspecialty sections and in radiology departments in general. Workload continues to increase, both in examination complexity and in numbers of overall procedures. Adjustment factors make workload comparisons between subspecialty sections more valid and meaningful.
Treatment of ischemic optic neuropathy

Ischemic damage of the optic nerve has no proven effective treatment. While ischemia related to vasculitis (arteritic) is treated with systemic corticosteroids, the primary goal is to prevent further damage, either in the affected or fellow eye. Thrombolytic or anticoagulation supplementive therapy may be considerations for the future. In the more common idiopathic (nonarteritic) form (NAION), multiple attempts at therapy, including systemic corticosteroids, anticoagulants and antiplatelet agents, diphenylhydantoin, hyperbaric oxygen, and optic nerve sheath decompression have been unsuccessful. The use of levodopa has been proposed but is unproven. Megadose intravenous corticosteroid therapy has not been studied in a systematic way. Neuroprotective strategies are under intense investigation for optic neuropathies including NAION, and clinical trials in humans are in progress. Optic nerve regeneration studies are ongoing in animals. Prophylaxis in NAION is unproven.
Bilateral tri-arterial embolization for the treatment of epistaxis.

Background: Intractable epistaxis is treated by ipsilateral trans-arterial embolization of the internal maxillary artery, but there is 13-26% recurrence of bleeding. Preemptive embolization of both internal maxillary arteries along with the ipsilateral facial artery could provide maximal protection against recurrent epistaxis. We report our experience with 8 patients treated with bilateral tri-arterial embolization. Methods: We performed a retrospective review of the patients who were treated with bilateral internal maxillary artery and ipsilateral facial artery embolization from January 2005 to January 2007. All patients had bleeding that was refractory to nasal packing. Results: Eight patients were treated with bilateral tri-arterial embolization. The median age was 65 years (range, 35-90 years). Risk factors included hypertension (n=4), smoking (n=2), alcohol (n=2), and use of anticoagulation (n=2). All but 2 of the patients were treated under local anesthesia. All patients had complete obliteration of bleeding during the procedure, with no residual vascular blush. No major peri- or post-procedural complications were noted. Patients stayed in the hospital for 2-4 days (average 2.6 days). One patient developed ipsilateral temporofacial pain which resolved during hospitalization. Another patient had minor recurrent epistaxis on post operative day 2 which resolved with temporary repacking and the patient was discharged the next day. Conclusion: In our experience with 8 cases, bilateral internal maxillary artery and/or ipsilateral facial artery embolization was achieved without complication and was associated with complete obliteration of vascular blush and no significant recurrent epistaxis.
Synthetic Ecology of Microbes: Mathematical Models and Applications

As the indispensable role of natural microbial communities in many aspects of life on Earth is uncovered, the bottom-up engineering of synthetic microbial consortia with novel functions is becoming an attractive alternative to engineering single-species systems. Here, we summarize recent work on synthetic microbial communities with a particular emphasis on open challenges and opportunities in environmental sustainability and human health. We next provide a critical overview of mathematical approaches, ranging from phenomenological to mechanistic, to decipher the principles that govern the function, dynamics and evolution of microbial ecosystems. Finally, we present our outlook on key aspects of microbial ecosystems and synthetic ecology that require further developments, including the need for more efficient computational algorithms, a better integration of empirical methods and model-driven analysis, the importance of improving gene function annotation, and the value of a standardized library of well-characterized organisms to be used as building blocks of synthetic communities.
Design of PZT cellular actuators with power-law strain amplification

The demand for high-force and compact actuators with large strain is increasing in robotics. PZT is known as one of the promising materials for this purpose with respect to bandwidth, stress, and reliability. However, the most critical drawback of PZT is its extremely small strain, i.e. only 0.1 %. This paper presents a nested rhombus structure for strain amplification of PZT stack actuators. This structure provides a "power-law" strain amplification, resulting in over 20 % strain, which is particularly useful for gaining a large strain in a compact body, appropriate for many robotic applications. The notational convention and fundamental force-displacement analysis will be presented. In addition, the feasibility of the design concept will be addressed through the design of a proof- of-concept prototype.
In-Reactor Deformation and Fracture of Austenitic Stainless Steels

An experimental technique for determining in-reactor fracture strain was developed and demonstrated. Differential swelling between a specimen holder and a test specimen with a lower swelling rate produced uniaxial deformation in 304 and cold-worked 316 stainless steel specimens. In-reactor deformations of 0.7 to 2.1% were achieved in Type 304 stainless steel previously irradiated to fluences up to 8.8 x 10/sup 26/ neutrons (n)/m/sup 2/ without fracture. These strains are significantly higher than found in postirradiation creep-rupture tests on similar specimens. From the measured strain values and published irradiation creep data and correlations, the stress levels during the irradiation were calculated. On the basis of previous postirradiation creep-rupture results, many of the specimens that did not fail would be predicted to fail. Thus we conclude that the in-reactor rupture life is longer than predicted by post-irradiation tests. Strain in a fractured specimen was estimated to be less than 3.8%, and in the in-reactor fractures were intergranular - the same fracture mode as found in postirradiation tests. Irradiation creep may relax stresses at crack tips and sliding boundaries, thus retarding the initiation or growth of cracks, or both, and leading to longer rupture lives in-reactor. However, the very high ductility or superplasticmore » behavior predicted by the strain-rate sensitivity or irradiation creep is not achieved because of the eventual interruption of the deformation process by grain boundary fracture.« less
Periodic solutions of nonlinear second-order difference equations

We establish conditions for the existence of periodic solutions of nonlinear, second-order difference equations of the form y(t + 2) + by (t + 1) + cy(t) = f (y(t)), where f: ℝ → ℝ and β > 0 is continuous. In our main result we assume that f exhibits sublinear growth and that there is a constant uf (u) > 0 such that |u| ≥ β whenever c = 1. For such an equation we prove that if N is an odd integer larger than one, then there exists at least one N-periodic solution unless all of the following conditions are simultaneously satisfied: |b| < 2, N across-1(-b/2), and π is an even multiple of c ≠ 0.
Proceedings of the 2009 annual meeting of the Fetal Alcohol Spectrum Disorders Study Group

The annual meeting of the Fetal Alcohol Spectrum Disorders Study Group (FASDSG) was held on June 20, 2009 in San Diego, CA, as a satellite of the Research Society on Alcoholism Meeting. The FASDSG membership includes clinical, basic, and social scientists who meet to discuss recent advances and issues in Fetal Alcohol Spectrum Disorders research. The main theme of the meeting was “Epigenetics and Development.” Two keynote speakers, Dr. Randy Jirtle and Dr. Michael Skinner, addressed the role of epigenetics and environmental inputs, including alcohol, during critical stages of development and their potential critical and long-lasting effects. Members of the FASDSG provided new findings through brief “FASt” data reports, and national agency representatives provided updates on activities and funding priorities. Scientific presentations were made by recipients of the Student Research Merit Award and Rosett Award.
The Response of the Coupled Arctic Sea Ice–Atmosphere System to Orbital Forcing and Ice Motion at 6 kyr and 115 kyr BP

Abstract A coupled atmosphere–mixed layer ocean GCM (GENESIS2) is forced with altered orbital boundary conditions for paleoclimates warmer than modern (6 kyr BP) and colder than modern (115 kyr BP) in the high-latitude Northern Hemisphere. A pair of experiments is run for each paleoclimate, one with sea-ice dynamics and one without, to determine the climatic effect of ice motion and to estimate the climatic changes at these times. At 6 kyr BP the central Arctic ice pack thins by about 0.5 m and the atmosphere warms by 0.7 K in the experiment with dynamic ice. At 115 kyr BP the central Arctic sea ice in the dynamical version thickens by 2–3 m, accompanied by a 2 K cooling. The magnitude of these mean-annual simulated changes is smaller than that implied by paleoenvironmental evidence, suggesting that changes in other earth system components are needed to produce realistic simulations. Contrary to previous simulations without atmospheric feedbacks, the sign of the dynamic sea-ice feedback is complicated and...
Role of neuronal nitric oxide synthase (NOS1) in the pathogenesis of renal hemodynamic changes in diabetes.

Nitric oxide (NO) has been implicated in the pathogenesis of renal hemodynamic changes in diabetes mellitus. However, the contribution of nitric oxide synthase (NOS) isoforms to intrarenal producti...
Albumin bolus administration versus continuous infusion in critically ill hypoalbuminemic pediatric patients.

Objective To test the hypothesis that the rate of degradation of exogenously administered albumin is fater with bolus administration that with continuous infusion and thus that a bolus administration is less efficacious in restoring blood albumin concentration (BAC) in the hypoalbuminemic critically ill pediatric patient.
A multivariate analysis of individual, situational and environmental factors associated with police assault injuries

Uses data on 1,550 nonlethal assaults recorded by Baltimore County Police Department. Examines factors that are associated with the likelihood of officer injury after an assault. Notes that factors affecting the probability of assault do not necessarily correspond with the factors that affect the likelihood of injury. Analyzes a broader spectrum of contributory factors than those addressed by other research. Finds inter alia that greater officer proficiency in unarmed defensive tactics may reduce their assault‐related injuries, since most incidents do not involve arms; that in‐service training should be biased toward less experienced officers who are at greater risk; that officer height is a significant variable; that many officers suffer multiple attacks; that domestic disturbances do not rank higher than other dangers, but that this may reflect the possibility that officers anticipate potential violence and take better precautions before attending the scene.