cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 6343: Mitochondrial bioenergetics mediate chemo-resistance of cancer cells

Background: Resistance to chemotherapy is a major cause of the failure of treatments in many cancers including pancreatic cancer. Accumulated evidence indicates that mitochondrial metabolic alterations are associated with cancer cells growth and proliferation. In this project, we investigated the role of mitochondrial bioenergetics in drug resistance. Methods: Human pancreatic cancer cell lines MIA PaCa-2 and HPAF-II and mouse pancreatic cancer cell line UN-KPC-961 were treated with increased doses of chemotherapy drug Gemcitabine for 4 months until developing resistance. Mitochondrial proteins, cancer stemness markers and metabolic enzymes were measured by Western and RT-PCR. Cell survival was measured by MTT assay. Mitochondrial bioenergetics were measured by Seahorse Assay. Results: We found that gemcitabine resistant (GR) cells grow at a much slower rate than wild type (WT) cancer cells; however, they express a significantly higher amount of cancer stemness markers such as Nanog, Oct4 and Sox2. They also expressed higher level of pro-cancer cytokines such as IL-6 and IL-4. Seahorse analysis showed a significantly lower oxygen consumption rate (OCR) in GR cells compared to WT cells. OCR did not change much in GR cells when applying inhibitors of the mitochondrial respiratory chain complex. GR cells produced lower level of ATP and lower spare respiratory capacity. However, GR cells expressed the same amount of mitochondrial proteins such as TOM40, TOM70 and COX4 suggesting the same mass of mitochondria. Pyruvate dehydrogenase-E1 Alpha1 (PDHA1) expression level was significantly lower in GR cells compared to WT cells. PDHA1 inhibition induced WT cells to develop a partial resistance to Gemcitabine; whereas, PDH1 overexpression in GR cells made these cells less resistant to Gemcitabine. Conclusion: We showed for the first time the difference in mitochondrial bioenergetics between WT and GR cells and showed that GR cells grow independently of the mitochondrial energy production machinery. Furthermore, we identified PDHA1 as a critical mediator of cancer drug resistance. Citation Format: Fouzia Zayou, Chintan Chheda, Stephen Pandol, Mouad Edderkaoui. Mitochondrial bioenergetics mediate chemo-resistance of cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6343.
Ultrafast Magnetic Field-Dependent Dynamics in the High-Temperature Superconductor La 2−x Sr x CuO 4

We performed optical-pump, terahertz-probe measurements on optimally doped La 2−x Sr x CuO 4 under an applied magnetic field. This reveals the strong interplay between magnetic and optical Cooper pair breaking that governs quasiparticle recovery dynamics in superconducting cuprates.
Performance on the Functional Movement Screen in older active adults.

Background The Functional Movement Screen (FMS™) has become increasingly popular for identifying functional limitations in basic functional movements. This exploratory and descriptive study was undertaken to confirm feasibility of performing the FMS™ in older active adults, assess prevalence of asymmetries and to evaluate the relationship between functional movement ability, age, physical activity levels and body mass index (BMI).
A 32-channel combined RF and B0 shim array for 3T brain imaging.

Purpose We add user-controllable direct currents (DC) to the individual elements of a 32-channel radio-frequency (RF) receive array to provide B0 shimming ability while preserving the array's reception sensitivity and parallel imaging performance. Methods Shim performance using constrained DC current (±2.5A) is simulated for brain arrays ranging from 8 to 128 elements. A 32-channel 3-tesla brain array is realized using inductive chokes to bridge the tuning capacitors on each RF loop. The RF and B0 shimming performance is assessed in bench and imaging measurements. Results The addition of DC currents to the 32-channel RF array is achieved with minimal disruption of the RF performance and/or negative side effects such as conductor heating or mechanical torques. The shimming results agree well with simulations and show performance superior to third-order spherical harmonic (SH) shimming. Imaging tests show the ability to reduce the standard frontal lobe susceptibility-induced fields and improve echo planar imaging geometric distortion. The simulation of 64- and 128-channel brain arrays suggest that even further shimming improvement is possible (equivalent to up to 6th-order SH shim coils). Conclusion Including user-controlled shim currents on the loops of a conventional highly parallel brain array coil is feasible with modest current levels and produces improved B0 shimming performance over standard second-order SH shimming. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.
A method for computing the DFT of vector quantized data

A method is presented for computing the discrete Fourier transform (DFT) of data compressed using vector quantization (VQ). The VQ compressed data are not reconstructed before use; instead, a codebook that has been processed with the DFT (discrete Fourier transform) algorithm is used for VQ reconstruction. An overlap-and-add technique is used to combine the processed reconstruction codebook vectors to give the DFT directly. The technique is suitable for both one-dimensional and multidimensional DFTs or, in general, any linear process. The technique is called the computation compression technique (CCT). The CCT implementation yields exactly the same result as if the compressed data had been reconstructed and the DFT performed on the data directly. CCT convolution on a 68020/6881-based computer is described. Speedups of two orders of magnitude are obtained. >
Knee cartilage defect: marrow stimulating techniques

Painful chondral defects of the knee are very difficult problems. The incidence of these lesions in the general population is not known since there is likely a high rate of asymptomatic lesions. The rate of lesions found during arthroscopic exam is highly variable, with reports ranging from 11 to 72 % Aroen (Aroen Am J Sports Med 32: 211-5, 2004); Curl(Arthroscopy13: 456-60, 1997); Figueroa(Arthroscopy 23(3):312-5, 2007;); Hjelle(Arthroscopy 18: 730-4, 2002). Examples of current attempts at cartilage restoration include marrow stimulating techniques, ostochondral autografts, osteochondral allografts, and autologous chondrocyte transplantation. Current research in marrow stimulating techniques has been focused on enhancing and guiding the biology of microfracture and other traditional techniques. Modern advances in stem cell biology and biotechnology have provided many avenues for exploration. The purpose of this work is to review current techniques in marrow stimulating techniques as it relates to chondral damage of the knee.
Vacuum Mixing Influence on Characteristics of Sectioned and Formed Beef Steak

Choice, Yield Grade 3 chucks were purchased vacuum packaged within 48 hr of slaughter. They were randomly allocated to treatments of vacuum or no vacuum mixing and 6 or 12 min mixing periods. The meat was formulated into sectioned and formed steaks. A trained sensory panel evaluated all samples and color scores were assigned to each steak. Instron adhesion measured binding of meat pieces, Kramer shear indicated tenderness, mg exudate/cm2 measured binding proteins. Reflectance spectrophotometry measured oxymyoglobin and metmyoglobin. Electrophoresis was used to separate and quantitate individual myofibrillar proteins. Sensory analyses indicated vacuum processed steaks had superior bind (P < 0.01) while juiciness, flavor and tenderness remained unchanged. Instron analyses indicated no difference in tenderness or bind strength due to vacuum. Subjective color analyses indicated less desirable color for vacuum mixing (P < 0.05) and the amount of oxymyoglobin and metmyoglobin were not changed due to treatment. There was less exudate at the bond site for vacuum mixing (P < 0.01). Sarcoplasmic and myofibrillar proteins were similar over vacuum treatment.
Analytic study of the Tadoma method: discrimination ability of untrained observers.

This study reports the ability of two observers with normal-hearing and sight to discriminate pairs of speech elements through the Tadoma method of speechread-ing. The observers were blindfolded an...
Deviations from LTE in a stellar atmosphere

Deviations for LTE are investigated in an atmosphere of hydrogen atoms with one bound level, satisfying the equations of radiative, hydrostatic, and statistical equilibrium. The departure coefficient and the kinetic temperature as functions of the frequency dependence of the radiative cross section are studied analytically and numerically. Near the outer boundary of the atmosphere, the departure coefficient is smaller than unity when the radiative cross section grows with frequency faster than with the square of frequency; it exceeds unity otherwise. Far from the boundary the departure coefficient tends to exceed unity for any frequency dependence of the radiative cross section. Overpopulation always implies that the kinetic temperature in the statistical-equilibrium atmosphere is higher than the temperature in the corresponding LTE atmosphere. Upper and lower bounds on the kinetic temperature are given for an atmosphere with deviations from LTE only in the optically shallow layers when the emergent intensity can be described by a radiation temperature.
Nocturnal low-level jet over a shallow slope

A simple theory is presented for a nocturnal low-level jet (LLJ) over a planar slope. The theory extends the classical inviscid inertial-oscillation model of LLJs to include up- and downslope motion in the boundary layer within a stably stratified environment. The particular scenario considered is typical of LLJs over the Great Plains of the United States: southerly geostrophic wind over terrain that gently slopes down toward the east. First, an initial value problem for the coupled equations of motion and thermodynamic energy is solved for air parcels suddenly freed of a frictional constraint near sunset. The solution is an oscillation that takes, on the hodograph plane, the form of an ellipse having an eastward-oriented major axis and an eccentricity that increases with increasing stratification and slope angle. Next, the notion of a tilted residual layer (TRL) is introduced and used to relate initial (sunset) air parcel buoyancy to free-atmosphere stratification and thermal structure of the boundary layer. Application of the TRL-estimated initial buoyancy in the solution of the initial value problem leads to expressions for peak jet strength and the slope angle that maximizes the jet strength. Analytical results are in reasonable qualitative agreement with observational data.
A New Method for Optimizing Friction Damping in Randomly Excited Systems

A method is developed that can be used to calculate the stationary response of randomly excited nonlinear systems. The method iterates to obtain the fast Fourier transform of the system response, returning to the time domain at each iteration to take advantage of the ease in evaluating nonlinearities there. The updated estimates of the nonlinear terms are transformed back into the frequency domain in order to continue iterating on the frequency spectrum of the staionary response.This approach is used to calculate the response of a one degree of freedom system with friction damping that is subjected to random excitation. The one degree of freedom system provides a single mode approximation of systems (e.g. turbine blades) with friction damping. This study investigates various strategies that can be used to optimize the friction load so as to minimize the response of the system.Copyright © 1989 by ASME
Bupivacaine provides rapid, effective periprostatic anaesthesia for transrectal prostate biopsy.

OBJECTIVE To examine the effectiveness of the longer acting agent bupivacaine in providing periprostatic anaesthesia during transrectal ultrasonography (TRUS)-guided biopsy, as the periprostatic injection of lidocaine has been shown to significantly alleviate the pain of this procedure. PATIENTS AND METHODS Seventy-five patients were randomized to receive a periprostatic injection with either bupivacaine, a lidocaine/bupivacaine (1/1) combination, or no local anaesthesia. Immediately before biopsy 5 mL of the anaesthetic was injected under TRUS guidance into the periprostatic nerves bilaterally. After taking a 10-core biopsy the patients were given a visual analogue scale (VAS; 0–10) to assess their pain during the procedure. RESULTS The mean VAS scores were 2.04 in the bupivacaine group and 4.46 in the control (no local anaesthetic) group (P < 0.001). CONCLUSIONS Bupivicaine provides significant, immediate periprostatic anaesthesia for TRUS biopsy.
Predicting public or private feedback-seeking behaviors

Purpose – The purpose of this paper is to examine whether the presence of an audience inhibits or facilitates feedback-seeking behaviors. Design/methodology/approach – A sample of 148 employees completed a survey questionnaire regarding feedback-seeking behaviors. Perceived value of public and private feedback, public self-consciousness (PSC), and tolerance for ambiguity were used to predict public or private feedback-seeking behaviors. Hierarchical multiple regression were used to test the hypotheses. Findings – Statistically significant relationships were found between perceived value of public feedback, PSC, tolerance for ambiguity, and public feedback seeking. Subsequently, statistically significant relationships were only found between perceived value of private feedback, tolerance for ambiguity, and private feedback seeking. Research limitations/implications – Future research should focus on how individuals respond to less privacy in the workplace in regards to feedback-seeking behaviors. Practical ...
Experimental Validation of a Thermal Model of Counterflow Microchannel Heat Exchangers Subjected to External Heat Flux

The effect of uniform external heat flux on the effectiveness of counterflow microchannel heat exchangers is experimentally studied in this article for validating an existing thermal model. The model validated in this study is a one-dimensional model previously developed by the same authors. The model is validated to be independent of microchannel profile, hydraulic diameter, and heat capacity ratio. For studying the effect of microchannel profile, experiments are conducted under balanced flow conditions using trapezoidal and triangular microchannels with approximately equal hydraulic diameter of 278.5 μm and 279.8 μm, respectively. The influence of hydraulic diameter on the thermal model is studied using a trapezoidal microchannel with hydraulic diameter of 231 μm and 278.5 μm. Experiments are conducted under unbalanced flow conditions, with a heat capacity ratio of 0.5, using the trapezoidal microchannel of hydraulic diameter of 278.5 μm. Deionized water is used as the fluid in all experiments. The hot ...
Calculation of an atom–surface scattering model using the S-matrix KVP

Abstract For the first time, we solve the model elastic atom–surface scattering problem with the S-matrix Kohn variational principle (KVP). The KVP consists of Hamiltonian matrix equations over a basis that includes both scattering and L2 functions. For ease of evaluation, we choose the L2 basis to be a pointwise representation (e.g. a discrete variable representation). Also for efficient solution, we use the reduced dimensional eigenbasis found by diagonalizing the Hamiltonian in the pointwise representation using the procedure of successive diagonalization and truncation. It is found that even upon further optimization, the KVP method appears to be too slow for solving large-scale single energy problems.The method is demonstrated to be efficient however, if the S-matrix elements for many different energies is desired.
Optical-model potential in single-nucleon-transfer reactions induced by heavy ions

Elastic scattering angular distributions were measured for /sup 48/Ca + /sup 16/O at 56 MeV and for /sup 45/Sc + /sup 15/N at 47.53 MeV. Extensive searches and systematic analyses of the optical-model potentials were performed to study ambiguities. Various potential sets that fit elastic scattering were used in distorted-wave Born approximation calculations of single-nucleon transfers. To a high degree the optical potential ambiguities that exist for elastic scattering persist for the transfer predictions. The distorted-wave Born approximation calculations are compared to experimental angular distributions of the single-proton transfer reactions /sup 48/Ca(/sup 16/O, /sup 15/N)/sup 49/Sc and /sup 48/Ca(/sup 19/F, /sup 18/O)/sup 49/Sc at 56 MeV and /sup 48/Ca(/sup 15/N, /sup 14/C)/sup 49/Sc at 48 MeV. The transfers are well predicted by the distorted-wave Born approximation when there is l matching between the entrance and exit channel dominant partial waves. For cases of l mismatch the calculations do not reproduce the data. This disagreement cannot be removed by changes in the optical potentials, if these are still required to describe elastic scattering. These results suggest the possible presence of reaction processes other than those treated in the conventional distorted-wave Born approximation amplitude. (AIP)
Planetary rings - 2-2/3 centuries of nearly total ignorance, 4 years of information explosion

Abstract Saturn lies at nearly twice Jupiter's distance from the Sun and nearly all parts of its system are characterized by much smaller scales than those which are important in the case of Jupiter. This appears in the structures of the planet's atmosphere, in the sizes of classical satellites other than Titan vis-a-vis those of the Galilean satellites, in the plethora of small Saturnian satellites, especially Lagrangian co-orbiters, in the structure of Saturn's F-Ring as contrasted with that of Jupiter's Ring and finally in the highly structured detail in Saturn's Rings, much finer than seriously considered in past theoretical discussions. Uranus' Rings were unknown until five years ago. The discovery and observation of these rings have revived contributions to theory originally intended for application to Saturn's Rings. Models have also been generated for eccentric rings for application to Uranus' Rings which also apply to those of Saturn. These two classes of model are reviewed in the present paper along with the first tentative steps made down the road to unravelling the complexity of Saturn's Rings.
Pupil-segmentation-based adaptive optics for in vivo brain imaging

Imaging deep inside a brain requires optical aberrations to be compensated to achieve high resolution. We utilize adaptive-optical methods based on pupil segmentation to correct these aberrations and achieve diffraction-limited resolution using two-photon fluorescence microscopy.
Toxicological screening by liquid chromatography

Abstract Toxicological screening commonly requires analysis of biological specimens by a variety of colorimetric, immunological and chromatographic techniques. Gas chromatography and thin-layer chromatography are useful for simultaneous identification of multiple drug classes, but both methods require sample pretreatment. Recently, liquid chromatography has been applied to untreated urine and serum. A series of columns are utilized for sample purification, as well as efficient separation of drugs. Multiple wavelength UV detection provides sufficient data for qualitative identification of drugs and their metabolites.
Sequence Dependence of Charge Transport through DNA Domains

Here we examine the photooxidation of two kinetically fast electron hole traps, N_4-cyclopropylcytosine (^(CP)C) and N_2-cyclopropylamine-guanosine (CPG), incorporated in DNA duplexes of various sequence using different photooxidants. DNA oxidation studies are carried out either with noncovalently bound [Ru(phen)(dppz)(bpy‘)]^(3+) (dppz = dipyridophenazine) and [Rh(phi)_2(bpy)]^(3+) (phi = phenanthrenequinone diimine) or with anthraquinone tethered to DNA. Because the cyclopropylamine-substituted bases decompose rapidly upon oxidation, their efficiency of decomposition provides a measure of relative hole localization. Consistent with a higher oxidation potential for ^(CP)C versus ^(CP)G in DNA, ^(CP)C decomposes with photooxidation by [Rh(phi)_2(bpy)]^(3+), while CPG undergoes ring-opening both with photoexcited [Rh(phi)_2(bpy)]^(3+) and with [Ru(phen)(dppz)(bpy‘)]^(3+). Anthraquinone-modified DNA assemblies of identical base composition but different base sequence are also probed. Single and double base substitutions within adenine tracts modulate ^(CP)C decomposition. In fact, the entire sequence within the DNA assembly is seen to govern ^(CP)C oxidation, not simply the bases intervening between ^(CP)C and the tethered photooxidant. These data are reconciled in the context of a mechanistic model of conformationally gated charge transport through delocalized DNA domains. Photooxidations of anthraquinone-modified DNA assemblies containing both ^(CP)C and ^(CP)G, but with varied distances separating the modified bases, point to a domain size of at least three bases. Our model for DNA charge transport is distinguished from polaron models. In our model, delocalized domains within the base pair stack form transiently based upon sequence-dependent DNA structure and dynamics. Given these results, DNA charge transport is indeed remarkably sensitive to DNA sequence and structure.
Juvenile myasthenia gravis

We studied 32 children with myasthenia gravis over a period of 12 years. The mean age at onset was 7.7 years. Presentation was ocular in 63% of patients. Another major disease in addition to myasthenia occurred in 44% of patients; a seizure disorder was the most commonly associated disease. Serum IgG antibody to nicotinic acetylcholine receptor was present in 53% of patients and did not correlate with severity of disease or treatment. Medical management was effective in 63%; thymectomy was effective in only 28%. We conclude that myasthenia gravis appears commonly before age 10 and is associated with the risk of some disease other than hyperthyroidism. Serum IgG nicotinic acetylcholine receptor antibody is present less frequently than in normal adults, and vigorous medical management should be attempted before thymectomy.
Valence-band structure of highly efficient p -type thermoelectric PbTe-PbS alloys

Experimental evidence is given relevant to the temperature dependence of the valence band structure of PbTe and PbTe${}_{1\ensuremath{-}x}$S${}_{x}$ alloys ($0.04\ensuremath{\le}x\ensuremath{\le}0.12$), and its effect on the thermoelectric figure of merit $ZT$. The $x=0.08$ sample has $ZT\ensuremath{\sim}1.55$ at 773 K. The magnetic field dependence of the high-temperature Hall resistivity of heavily $p$-type ($g{10}^{19}$ cm${}^{\ensuremath{-}3}$) Na-doped PbTe${}_{1\ensuremath{-}x}$S${}_{x}$ reveals the presence of high-mobility electrons. This casts doubts on prior analyses of the Hall coefficient suggesting that temperature induces a rapid rise in energy of the ``heavy'' hole relative to the ``light'' hole bands. The electron-like behavior is likely induced by the topology of the Fermi surface when the L- and \ensuremath{\Sigma}-bands merge. Negative values for the low-temperature thermopower are also observed. The data show that PbTe continues to be a direct-gap semiconductor at temperatures where the $ZT$ and ${S}^{2}\ensuremath{\sigma}$ of $p$-type PbTe are optimal, e.g., 700--800 K.
Receptor Sites on Human Monocytes for Complement: BINDING OF RED CELLS SENSITIZED BY COLD AUTOANTIBODIES

Summary Receptor sites on isolated human monocytes were assessed by the demonstration of rosette formation by sensitized red cells around monocytes. This type of binding to monocytes occurred using red cells sensitized with a typical monoclonal IgM cold agglutinin but (in contrast to IgG antibodies) only if the red cells were also coated with complement (C) components. Prior treatment of monocytes with trypsin (1 mg/ml) inhibited the detection of the C receptor but not the detection of the IgG receptor. Although this reaction resembled the phenomenon of immune adherence to some extent, it required the presence of Mg2+ ions and was inhibited by EDTA. The effects of temperature variation on C-dependent rosette formation and on haemolysis were comparable. The binding of sensitized erythrocytes to monocytes, however, required significantly less antibody than for haemolysis. C-coated red cells remained reactive with mononuclear phagocytes after elution of the cold antibody as well as under conditions when C was bound to red cells without antibody.
Do practical durations of stretching alter muscle strength? A dose-response study.

ABSTRACTPurpose:To examine the time course (immediate, 10, 20, and 30 min) for the acute effects of 2, 4, and 8 min of passive stretching (PS) on isometric peak torque (PT), percent voluntary activation (%VA), EMG amplitude, peak twitch torque (PTT), rate of twitch torque development (RTD), and rang
Vigilant at the End of Life: Family Advocacy in the Nursing Home

Abstract Background: Increasing numbers of Americans die in nursing homes. Little is known about the roles and experiences of family members of persons who die in nursing homes. Methods: The authors conducted 54 qualitative telephone interviews of close family or friends of individuals who had spent at least 48 hours in the last month of life in a nursing home. Respondents had earlier participated in a national survey that found 587 of 1578 decedents (37.2%) received end-of-life nursing home care. In qualitative interviews respondents described the last year of life, focusing on the nursing home experience. Interviews were analyzed by a multidisciplinary team to identify key themes of areas of concern. Results: An important interview theme revealed families often felt the need to advocate for their dying relative because of low expectations or experiences with poor quality nursing home care. They noted staff members who did not fully inform them about what to expect in the dying process. Respondents repor...
The Last Italian Philosopher: Eugenio Garin (with an Appendix of Documents)

Eugenio Garin, Interpretazioni del Rinascimento, edited by Michele Ciliberto, 2 vols (Rome: Edizioni di Storia e Letteratura, 2009), vol. 1 (1938–47), lvi + 247 pp., €38.00 (pb), ISBN 978-88-6372-0...
Fault plane solutions of earthquakes on the Nazca plate boundaries and the Easter plate

Abstract Thirteen new and fourteen published earthquake fault plane solutions are used to examine the directions of the relative plate motion along the boundaries of the Nazca plate on the East Pacific Rise, Galapagos Spreading Center, and Chile Rise. In general, slip vectors agree well with one another and with the directions of plate motion given by Minster et al. A few solutions that disagree with these inferred directions of plate motion corroborate the independent evidence and suggestions of Forsyth and Herron that two small plates exist along the East Pacific Rise crest. Together, magnetic anomalies, bathymetry, seismicity and the fault plane solutions suggest that the northernmost of these two plates, the Easter plate, is bounded on the north by transform faults and on the south by spreading centers. The existence of the diamond-shaped Easter plate may be related to (1) its close proximity to Easter Island (a proposed hot spot) or, (2) the very high velocities of plate motion and, therefore, the thin lithosphere in this region.
Classical and dynamic resolution of 1 -amino-3-methyl-1 ,3,4,5-tetrahydrobenzo[d]azepin-2-one

Abstract Two efficient production processes of enantioenriched 1-amino-3-methyl-1,3,4,5-tetrahydro-benzo[d]azepin-2-one 1 were achieved using the readily available starting materials. A key step in the methodologies is a classical resolution or a dynamic resolution that provides excellent chemical (>80%) yields and enantiomeric excesses (>99.8% ee). The classical resolution was developed on a preparative scale while the dynamic resolution was implemented on a pilot plant scale.
Solvent quality changes the structure of G8 PAMAM dendrimer, a disagreement with some experimental interpretations.

We have performed ∼20−40 ns of molecular dynamics (MD) simulations for the generation 8 PAMAM dendrimer in explicit water under varying pH conditions to study the structure of the dendrimer (∼156 738 atoms at low pH). This is the first report of such a long MD simulation of a larger generation PAMAM dendrimer including the effect of salt and counterions with explicit water molecules. We find that changing the pH from a high value (∼12) to a low value (∼3) changes the radius of gyration from Rg = 37.8 to 43.1 A (increasing by 13%). We also find significant back-folding of the primary amines and a large amount of water penetration inside the polymer. The increase in size with decrease in pH is consistent with our earlier studies on G3−G6 and agrees with the Monte Carlo theory by Welch and Muthukumar of G8 (Macromolecules, 1998, 31, 5892) and the experiments on G5 and G8 PAMAM dendrimer by Topp et al. (Macromolecules, 1999, 32, 7232). However, these results disagree dramatically with the interpretations of S...
Combining social authentication and untrusted clouds for private location sharing

Recently, many location-sharing services (LSSs) have emerged that share data collected using mobile devices. However, research has shown that many users are uncomfortable with LSS operators managing their location histories, and that the ease with which contextual data can be shared with unintended audiences can lead to regrets that sometimes outweigh the benefits of these systems. In an effort to address these issues, we have developed SLS: a secure location sharing system that combines location-limited channels, multi-channel key establishment, and untrusted cloud storage to hide user locations from LSS operators while also limiting unintended audience sharing. In addition to describing the key agreement and location-sharing protocols used by SLS, we discuss an iOS implementation of SLS that enables location sharing at tunable granularity through an intuitive policy interface on the user's mobile device.
SU-C-500-02: Comparison of a Commercial Electronic Brachytherapy Source and Ir-192/Co-60 HDR Source for Endometrial and Cervical Cancers

Purpose: To evaluate the dosimetric differences between Iridium-192, Co-60 based HDR plans and plans generated by electronic brachytherapy source (EBS) for cervical and endometrial cancers. Material/Methods: Our institution uses volume based planning for each tandem and ovoid (T&O) or vaginal cylinder insertion and treatment. We attempt to characterize the differences between the three sources (Ir-192, Co-60 and EBS). For vaginal cylinder cases, patients receive 6 Gy x3 prescribed to a depth 5 mm. For T&O cases, the prescription is 8Gy x3 to point A. Organs at risk (OARs) contoured were rectum, bladder, sigmoid & small bowel. Our planning protocol requires adjustment of source dwell times and positions to keep doses to the OARs below 70% of the prescription dose. For vaginal cylinder, dose coverage is optimized to a line drawn 5mm from the vaginal cylinder surface. This is a retrospective study of previously planned Ir-192 treated patients. Results: There is no difference between the Co-60 and Ir-192 plans but plans generated using the EBS offer better sparing of OARs as evaluated using the dose to highest 2cc of the organ at risk but the differences are not statistically significant. However, there are significant differences in the DVH between EBS and the other two sources. There was a reduction of up to 50% between EBS and other two sources using v15%, v25%, v50% v75% (% of volume getting 15, 50, 75 percent of the prescription dose). Conclusion: All three sources are suitable for HDR Brachytherapy but the use of EBS can reduce the organ at risk dose while achieving similar dose coverage. Even though D2cc is the recommended dose volume point for HDR plans evaluation, V15%, V25%, V50% and V75% are also useful indicator of the plan quality as they characterize the lower dose region of the DVH curves more adequately
Effect of calcification on in vivo mechanical response of rabbit arteries to balloon dilation.

BACKGROUNDAtherosclerosis has been associated with loss of artery wall distensibility in human cadavers and in experimental animal models, giving it the lay term "hardening of the arteries."METHODS AND RESULTSTo assess the effect of calcification on arterial distensibility, balloon pressure and volume were recorded during dilation of calcified aortas in Watanabe heritable hyperlipidemic (WHHL) rabbits in vivo. Calcification was induced by dietary supplements of cholesterol, vitamin D2, and calcium. Balloon pressure, volume, and time signals were acquired at high frequency with controls for temperature and balloon inflation rate. Resistance to balloon dilation was minimal in control rabbit aortas (delta Vmax = 5.0 +/- 3.5 microliters) and in excised nonatherosclerotic human coronary arteries, and it was small in aortas from cholesterol-fed rabbits (12.3 +/- 8 microliters), even when lipid levels were markedly elevated by a high cholesterol diet (611 +/- 347 mg/dl). With dietary cholesterol, vitamin D2, and...
A Computer-Controlled Rotating-Belt Hand for Object Orientation

Semiautomated tasks frequently require humans to perform highly repetitive boring jobs such as placing objects into machine fixtures. The use of an electromechanical hand design is discussed which may operate in conjunction with industrial robots, part feeders, and minicomputers to perform some of these jobs. Flexibility is achieved with the same hardware by using different control algorithms for differently shaped objects. The design principle which permits simplicity is that the motion which is used to adjust object orientation is also instrumental in the detection of orientation. A ``hand'' was built and a control algorithm to orient a specific object was developed. The control algorithm first recognizes orientation by computing asymmetries and then conditionally adjusts a positional servomechanism in the hand to bring the object to a standard orientation. Tests verified hand performance and indicated restrictions on object shape. Regardless of the initial angle (360° range) about the uncontrolled axis, the computer-controlled hand adjusted this angle to within ±3°. For the prototype, object shape is primarily restricted by the requirement that objects must have their principal axes directed to within ±10° by conventional part feeders and sorters.
In-situ TEM observation of aluminum embrittlement by liquid gallium

Liquid metal embrittlement (LME) occurs when some solids contact certain liquid metals. Normally ductile materials will exhibit brittle fracture behavior because of interactions between the solid metal and adsorbed liquid atoms. The fracture characteristics of different solid-liquid metal couples vary greatly. A requirement is that the liquid wets the surface of a solid. Ductile materials fail over a period of time, by slow and often discontinuous crack growth. For embrittlement to occur, the liquid metal atoms must be adsorbed at the crack tip. If the crack extends beyond the adsorbed atoms, it may become blunted and arrest. Thus the time necessary for failure depends on the transport of liquid metal atoms to the crack tip. The aluminum-gallium system exhibits this type of time-dependent failure. Liquid gallium penetrates the grain boundaries so that failure occurs primarily by intergranular fracture at applied stress levels as low as zero, although transgranular cleavage is sometimes observed for applied stress intensities of 4--5 MPa-m{sup 1/2}. This penetration proceeds much faster than can be accounted for by grain boundary diffusion, and occurs in the absence of any applied stress. The driving force is generally considered to be the reduction in interfacial energy which results when amore » high energy grain boundary is replaced with two lower energy aluminum-gallium interfaces. This study reports the results of grain boundary penetration observed in-situ in the TEM.« less
Transforming A Family of Curves into A Family of Curves with A Single Shape.

The relatively hard problem of transforming a given set of curves to curves with the same shape can sometimes be reduced to the easier problem of rendering curves parallel. In this paper a group is associated with the given curves, and it is shown that the reduction from the hard problem to the easy problem is valid whenever the group is nonabelian. A comprehensive review of earlier work is included so that this paper can be read alone. Applications to psychological measurement are cited briefly.
Cross-layer design of ad hoc networks for real-time video streaming

Cross-layer design breaks away from traditional network design where each layer of the protocol stack operates independently. We explore the potential synergies of exchanging information between different layers to support real-time video streaming. In this new approach information is exchanged between different layers of the protocol stack, and end-to-end performance is optimized by adapting to this information at each protocol layer. We discuss key parameters used in the cross-layer information exchange along with the associated cross-layer adaptation. Substantial performance gains through this cross-layer design are demonstrated for video streaming.
Design and prototyping of an actuator for vibration control

To assist in the development of vibration isolation systems, we have developed an actuator which seeks to improve performance using only internal position measurements. As such, the actuator can act as a variable-stiffness member and can improve vibrational performance of the structure. In addition to providing good isolation itself, such as actuator also has the potential to enhance the performance of systems based on more sophisticated controllers.
Idealized two dimensional sintering by interface diffusion

The authors consider an idealized two-dimensional model of the sintering of a close packed array of cylindrical grains with equivalent planar grain boundaries (GB) midway between each pair of cylinders. The scale and temperature are assumed to be such that material transport is completely dominated by diffusion along the GB's and on the pore surfaces; lattice diffusion is therefore neglected. This requires the condition D[sub gb]a[sub 0]/D[sub L]L >> 1, where D[sub gb] and D[sub L] are respectively the grain boundary and the lattice diffusion coefficients, a[sub 0] is an atomic dimension and L is the order of the cylinder radius. For particles sizes of 1 micrometer or less, of interest in the sintering of very fine powders, this condition is satisfied except possibly very near the melting point. The treatment takes into account an applied hydrostatic pressure during sintering but assumes that it is insufficient to cause plastic flow. Further, they ignore complications such as grain growth and the concomitant dragging and/or abandonment of pores by GB's, as well as the coarsening of pores. Possible extensions of the model to estimate the effect of these complications are discussed in the last section. As material moves from the GB's intomore » the pores, thereby permitting the movement of the cylinders together, it will tend to alter the shape of the pores. They shall show, however, that it is reasonable to assume that surface diffusion is sufficiently rapid to redistribute the material and maintain the pore in the shape it would have in static equilibrium.« less
Ethosearch: A New Online Resource for Ethograms and Evaluating Behavior and Welfare

Ethograms, as compiled catalogs of a species' behavioral repertoire, represent a fundamental underpinning of behavioral research. Well-designed ethograms underlie any rigorous quantitative study of...
Kinetics of uncatalyzed isomerization of aliphatic ketoximes

Abstract Three acyclic, aliphatic ketoximes studied show similar rates of isomerization at room temperature. From the rates of isomerization of one oxime at four temperatures, the thermodynamic activation parameters are calculated and a bimolecular transition state is postulated to account for the large negative entropy of activation.
Purine and pyrimidine inhibitors of arginase.

Abstract 1. 1.|Adenosine, inosine, adenine and uric acid are competitive inhibitors, and cytidine and cytosine noncompetitive inhibitors of bovine liver arginase ( l -arginine amidinohydrolase, EC 3.5.3.1). 2. 2.|The affinity of the enzyme for these inhibitors was 10–100 times as great as for substrate in terms of Ki versus Km. 3. 3.|These nucleic acid metabolites may thus function in vivo to regulate the urea cycle. 4. 4.|Several naturally occurring competitive and noncompetitive inhibitors of arginase of unknown structure have been isolated from plant and animal tissue. From their properties and methods of isolation, they may be the purines and pyrimidines herein described. 5. 5.|These purines and pyrimidines have no effect on tryptic hydrolysis.
The Implications of Reliability Theory for Environmental Institutional Design and Decision Making

Despite being a pillar of modem economic thinking, expected utility theory (EUT) has many limitations for explaining behavior in the presence of uncertainty. These limitations are well known and oft repeated (e.g., Arrow, Runge and Myers), but economists have just begun to pursue other theoretical frameworks for understanding how both market and nonmarket institutions cope with real-world uncertainty. The potential rewards of this pursuit are ample since EUT's contribution has been at the individual decision-making level, whereas the most serious theoretical deficiencies are in accounting for the linkages from individual decisions to institutional formation and behavior (Coleman, p. 184). The merit of the pursuit notwithstanding, uncertainty is a difficult analytical concept because it has been confused with discussions of risk and subjective probability distributions. To further the confusion, many writers have resorted to pretentious adjectives such as "profound" and "irresolvable" (Goodin) or "structural" (Walters) to distinguish true uncertainty. In the spirit of Knight, the clearest definition of uncertainty is lack of knowledge of states or actions and, at the extreme, sheer ignorance.1 Uncertainty created by imperfect knowledge and humans' limited reasoning skills is the most dominant consideration in understanding any organization or living system (Hodgson, Kay, Walters). One key problem for any theory of institutional behavior under uncertainty is to explain the origin and stability of institutions rather than simply to treat them as exogenous. Neoclassical decision models based on EUT have limited value for this task because the market institution is the centerpiece of analysis. Other social institutions are viewed as constraints, and information problems are defined as transactions costs that only impact the allocation from exchange (e.g., Dahlman, Schmid, Williamson). As a result, the influence of uncertainty on the origin and functions of these institutions is not fully explored.2 The recent work of Heiner (1983, 1985, 1986) on reliability theory (RT) offers an alternative theoretical framework to explain institutions as responses to problems of uncertainty. Given that institutions are a "regularity in social behavior" (Schotter, p. 11), RT is promising because it "directly harnesses the determinants of uncertainty to characterize regularity in behavior" (Heiner 1983, p. 571). In the following section, we outline the basic principles of RT and contrast it with EUT. We then explore the implications of RT for the The authors are associate professors in the Food and Resource Economics Department, University of Florida. Florida Agricultural Experiment Station Journal Series No. 9215.
A neural network-based methodology for pavement crack detection and classification

Abstract This paper presents a methodology for automating the processingof highway pavement video images using an integration of artificial neural network models with conventional image-processing techniques. The methodology developed is able to classify pavement surface cracking by the type, severity, and extent of cracks detected in video images. The approach is divided into five major steps: (1) image segmentation, which involves reduction of a raw gray-scale pavement image into a binary image, (2) feature extraction, (3) decomposition of the image into tiles and identification of tiles with cracking, (4) integration of the results from step (3) and classification of the type of cracking in each image, and (5) computation of the severities and extents of cracking detected in each image. In this methodology, artificial neural network models are used in automatic thresholding of the images in stage (1) and in the classification stages (3) and (4). The results obtained in each stage of the process are presented and discussed in this paper. The research results demonstrate the feasibility of this new approach for the detection, classification, and quantification of highway pavement surface cracking.
Instrumental Grammar for Conversation

Author's Summary— The intellectual “jigsaw-puzzle” conception of language-learning contrasted with the “expanding snowball” conception in terms of a year's running-unit in the basic essentials of grammar for conversation. Classroom-tested procedures illustrated with specific suggestions for their use with large high-school groups whenever specialized practice in grammar is actually needed as an aid in promoting ability to read write, and converse.
Patient perceptions of multiple gestations: An assessment of knowledge and risk aversion

Abstract Objective: To determine whether knowledge of the increased risk of certain pregnancy complications affects a woman's desire to achieve a multifetal gestation. Study Design: Women who attended an infertility clinic were given an interviewer-administered survey that ascertained how intensely they desired a multifetal pregnancy and how accurately they perceived the risks of multifetal complications. In addition, 5-point Likert scales were used to assess how different perceptions of risk affected the desire for gestations of different plurality. Results: Most respondents (67%) expressed the desire to conceive a twin pregnancy, although they could not accurately estimate the probability of risks associated with this type of pregnancy. Nevertheless, their desire was affected by perceptions of pregnancy-associated risk. On the basis of ordinal regression, desire for twins was more likely after in vitro fertilization ( P P P P Conclusion: Women who undergo treatment for infertility are not well aware of the risks of perinatal complications associated with multiple gestations. Moreover, these women are risk sensitive and change their desires on the basis of their perception of overall risk. (Am J Obstet Gynecol 2001;185:920-4.)
Electron-Phonon Interaction in the Tight-Binding Approximation: Validity of the Bloch Formulation

We show that the Bloch formulation of the electron-phonon interaction is valid in the tight-binding limit, correctly describes the rigid response of the tightly bound electrons to the ion motion, and introduces corrections of first order in the bandwidth to the "modified-tight-binding" approximation of Frohlich and Mitra and the "Hubbard-Hamiltonian" approximation of Bari\ifmmode \check{s}\else \v{s}\fi{}i\ifmmode \acute{c}\else \'{c}\fi{}, Labb\'e, and Friedel. Expressions are derived for the Bloch tight-binding electron-phonon matrix elements.