cssi/SciSciGPT-SciSciNet huggingface dataset:
Breaking the cycle of medication overuse headache

When patients who have frequent, disabling migraines take medications to relieve their symptoms, they run the risk that the attacks will increase in frequency to daily or near-daily as a rebound effect comes into play. This pattern, called medication overuse headache, is more likely to happen with butalbital and opioids than with migraine-specific drugs, as partial responses lead to recurrence, repeat dosing, and, eventually, overuse. Breaking the cycle involves weaning the patient from the overused medications, setting up a preventive regimen, and setting strict limits on the use of medications to relieve acute symptoms.
Microsomal Triglyceride Transfer Protein Enhances Cellular Cholesteryl Esterification by Relieving Product Inhibition

Cholesteryl ester synthesis by the acyl-CoA:cholesterol acyltransferase enzymes ACAT1 and ACAT2 is, in part, a cellular homeostatic mechanism to avoid toxicity associated with high free cholesterol levels. In hepatocytes and enterocytes, cholesteryl esters are secreted as part of apoB lipoproteins, the assembly of which is critically dependent on microsomal triglyceride transfer protein (MTP). Conditional genetic ablation of MTP reduces cholesteryl esters and enhances free cholesterol in the liver and intestine without diminishing ACAT1 and ACAT2 mRNA levels. As expected, increases in hepatic free cholesterol are associated with decreases in 3-hydroxy-3-methylglutaryl-CoA reductase and increases in ATP-binding cassette transporter 1 mRNA levels. Chemical inhibition of MTP also decreases esterification of cholesterol in Caco-2 and HepG2 cells. Conversely, coexpression of MTP and apoB in AC29 cells stably transfected with ACAT1 and ACAT2 increases cholesteryl ester synthesis. Liver and enterocyte microsomes from MTP-deficient animals synthesize lesser amounts of cholesteryl esters in vitro, but addition of purified MTP and low density lipoprotein corrects this deficiency. Enrichment of microsomes with cholesteryl esters also inhibits cholesterol ester synthesis. Thus, MTP enhances cellular cholesterol esterification by removing cholesteryl esters from their site of synthesis and depositing them into nascent apoB lipoproteins. Therefore, MTP plays a novel role in regulating cholesteryl ester biosynthesis in cells that produce lipoproteins. We speculate that non-lipoprotein-producing cells may use different mechanisms to alleviate product inhibition and modulate cholesteryl ester biosynthesis.
Thallium-201 myocardial perfusion imaging in aortic valve stenosis

Abstract The clinical utility of thallium-201 myocardial perfusion imaging in aortic valve stenosis was evaluated at rest and after exercise in three groups of patients: (1) 20 normal subjects, (2) 11 patients with aortic valve stenosis and coronary artery disease (70 percent or greater narrowing of luminal diameter), 11 patients with aortic valve stenosis without coronary artery disease (30 percent or less narrowing). Seven of the latter 22 patients also had postoperative imaging studies. None of the normal subjects had perfusion abnormalities either at rest or after maximal exercise. Three patients with aortic stenosis and coronary artery disease and one with aortic stenosis alone had focal perfusion defects present at rest suggesting prior myocardial infarction. Five patients with aortic stenosis and coronary artery disease manifested new focal perfusion defects and also a pattern of widespread left ventricular wall “thinning” in the postexercise thallium image suggesting diffuse subendocardial ischemia; three had wall “thinning” alone, and two no change in resting focal defects. Five patients with aortic stenosis without coronary artery disease also manifested focal perfusion defects and wall thinning; one had wall thinning alone, and one a new focal defect alone. Two patients had new resting focal defects after surgery, suggesting perioperative damage, and four patients no longer had either the focal or the diffuse pattern of exercise ischemia seen preoperatively. Thallium-201 imaging is of value in assessing the results of surgery in aortic stenosis. However, the technique does not allow adequate separation of patients with aortic stenosis and coronary artery disease from those with aortic stenosis alone because (1) angiographically significant coronary artery disease may not always produce focal ischemia before diffuse subendocardial ischemia develops, and (2) angiographically insignificant coronary artery disease may become functionally critical in the presence of aortic stenosis and produce focal ischemia.
Extracellular calcium ionic activity in experimental spinal cord contusion

Abstract Entry of calcium ions (Ca2+) into axons has been hypothesized by several investigators to play a major role in myelopathy of spinal trauma. Although some evidence supports this hypothesis, a rapid and large influx of Ca2+ into cells prior to development of necrotic changes has not been demonstrated in spinal injury. Because large influxes of Ca2+ into cells are manifested by decreases in extracellular Ca2+, we measured extracellular Ca2+ activity in contused cat spinal cords, using ion-selective microelectrodes and relating the Ca2+ changes to local blood flow and evoked potentials. Within 5 min of 400 g·cm contusion, we found decreases of spinal extracellular Ca2+ from normal pre-injury levels (1.0–1.3 mM) to The initial extracellular Ca2+ fall preceded the onset of significant blood flow changes in spinal cord white matter. Thus, the Ca2+ change was related to the trauma and not to subsequent blood flow alterations. Evoked potentials often recovered transiently at 1–2 h after injury, suggesting that some axons were not immediately destroyed by the contusion and their subsequent survival or function was influenced by factors other than the initial Ca2+ derangement. Neither blood flow changes nor action potential conduction recovery depended on specific levels of extracellular Ca2+. In conclusion, our data support the hypothesis of Ca2+-mediated injury of spinal tracts but additional work is required to define the role of Ca2+ in the later phases of spinal injury.
The electoral college vs. a direct vote: Policy bias, reversals, and indeterminate outcomes†

In this essay we address three issues from the debate over substituting a direct vote for the Electoral College: (1) the extent to which the Electoral College induces candidates to advocate policies that they would not advocate under a direct vote; (2) the probability that the winner under a direct vote is not the winner under the Electoral College; and, (3) the probability that third parties—both national and regional—force elections into Congress. We conclude, first, that while candidate platforms are sensitive to election procedure, the likelihood of politically significant differences has diminished over time. Second, computing the probability of reversals in 2‐candidate contests, we find that, even in close elections, this probability does not exceed 0.2. Finally, and contrary to our initial supposition, we conclude that regional as against national third parties are not necessarily more likely to induce indeterminate outcomes, ceteris paribus. We also explore situations in which the Electoral Colleg...
Interaction between ATP, metal ions, glycine, and several minerals

Interactions between ATP, glycine and montmorillonite and kaolinite clay minerals in the presence of various metal cations are investigated. The adsorption of adenine nucleotides on clays and Al(OH)3 was measured as a function of pH, and glycine condensation was followed in the presence of ATP, ZnCl2, MgCl2 and either kaolinite or montmorillonite. The amounts of ATP and ADP adsorbed are found to decrease with increasing Ph, and to be considerably enhanced in experiments with Mg(2+)- and Zn(2+)-montmorillonite with respect to Na(+)-montmorillonite. The effects of divalent cations are less marked in kaolinite. Results for Al(OH)3 show the importance of adsorption at clay platelet edges at high pH. The decomposition of ATP during drying at high temperature is observed to be inhibited by small amounts of clay, vacuum, or Mg(2+) or Zn(2+) ions, and to be accompanied by peptide formation in the presence of glycine. Results suggest the importance of Zn(2+) and Mg(2+) in chemical evolution.
Density Functional Theory of Open-Shell Systems. The 3d-Series Transition-Metal Atoms and Their Cations

The 3d-series transition metals (also called the fourth-period transition metals), Sc to Zn, are very important in industry and biology, but they provide unique challenges to computing the electronic structure of their compounds. In order to successfully describe the compounds by theory, one must be able to describe their components, in particular the constituent atoms and cations. In order to understand the ingredients required for successful computations with density functional theory, it is useful to examine the performance of various exchange–correlation functionals; we do this here for 4sN3dN′ transition-metal atoms and their cations. We analyze the results using three ways to compute the energy of the open-shell states: the direct variational method, the weighted-averaged broken symmetry (WABS) method, and a new broken-symmetry method called the reinterpreted broken symmetry (RBS) method. We find the RBS method to be comparable in accuracy with the WABS method. By examining the overall accuracy in t...
On formulas of Ramanujan and Evans

We give short elementary proofs of a formula of Ramanujan as interpreted by Bradley, and a companion formula originally proved by W. Chu. We also give an elementary proof of a generalization of an identity originally proved using modular functions and used to study a generating function for the number of partitions with specified crank.
Promoting effects of phenobarbital and barbital on development of thyroid tumors in rats treated with N-bis(2-hydroxypropyl)nitrosamine.

Phenobarbital (PB) and barbital (BB) promoted the development of thyroid tumors in rats treated with a sub-effective dose of N-bis(2-hydroxypropyl)nitrosamine (DHPN) for thyroid tumorigenesis. Rats were given s.c. injections of 70 mg DHPN/100 g body weight once a week for 4 or 6 weeks with or without diet containing 500 p.p.m. PB or BB for the next 12 weeks. The incidences of thyroid tumors at the end of week 20 of the experiment were 66% in rats given DHPN for 4 weeks and then PB, 23% in rats given DHPN for 4 weeks and then BB, 100% in rats given DHPN for 6 weeks and then PB, 45% in rats given DHPN for 6 weeks and then BB, and 23% in rats given DHPN for 6 weeks. Rats given only DHPN for 4 weeks or only PB or BB had no thyroid tumors after 20 weeks.
A characterization study of highly tailorable 3D metamaterials in the thermal infrared for selective emission behaviors

The spectral behaviors of an externally-illuminated thermal infrared metamaterial were characterized through simulation and experimental measurement of the power transmittance and reflectance within the 6 - 20μm range. Finite-difference time domain (FDTD) simulations in both 2-D and 3-D environments were swept over a multitude of bent dipole inclusion configurations at normal incidence angles to produce a model which exhibited a dominant electrical resonance in the long-wave infrared (IR) and increased in magnitude, bandwidth and wavelength as a function of the dipole length. Despite the appearance of fabrication defects in the measured samples, it was found the experimental data was in good agreement with the 3-D FDTD simulations, though not at all with the 2-D simulations. These introductory results indicate the dipole inclusion may behave in many ways similar to an antenna in the IR, enabling spectrally- and spatially-selective control of the emission pattern.
PROBABILITIES OF PROMPT-NEUTRON EMISSION FROM SPONTANEOUS FISSION

The neutron number distributions from the spontaneous fission of seven isotopes have been measured by use of a cadmium-loaded liquid scintillation tank. The experimental distributions can be roughly approximated by binomial distributions.
Landmark-based localization for Unmanned Aerial Vehicles

Localization is an aspect of robotics that is of fundamental importance in the deployment of autonomous vehicles. Robots need to know where they are relative to a global frame of reference, or other robots. Robot odometry is a trivial way of acquiring distance travelled by an autonomous vehicle. However, odometry has inherent flaws such as errors caused by wheel slippage on ground based vehicles. Other platforms like Unmanned Aerial Vehicles (UAVs) have built-in odometry capabilities that can be affected by drift. Further, the Global Positioning System (GPS) has a 10 foot error, which contributes a significant error to the robots location as discussed in [10]. Landmark-based localization is an ideal supplement to odometry and GPS. Recognition of landmarks such as tags or terrain using cameras can provide localization data. The Parrot AR drone was the platform for the landmark-based localization experiments. The real-time camera feeds from the drone along with ROS' (Robot Operating System) AR tag node provided the parameters: roll, pitch, yaw, x-metric, y-metric, z-metric. Utilizing a mathematical algorithm and the camera feed, the relative position of the drone to a point of origin was calculated. The error associated with the position was an acceptable 100mm-150mm, which was a significant improvement compared to other localization methods. Landmark-based localization is proving to be an effective way to attain position information when other sources such as GPS are unavailable as described in [11]. Despite its advantages, certain limitations and challenges need addressing. Dealing with limitations in camera image quality, lighting and locale restrictions would require further exploration.
Electrochemical Protection of Molybdenum and Molybdenum Disilicide in Molten Soda-Lime-Silicate Glass Environment

Electrochemical corrosion of Mo and MoSi2 in a molten soda-lime-silicate glass environment was studied using a two electrode cell with Pt as the counter electrode. XRD, SEM, and EDS were used to characterize the corroded specimens. When Mo was given a cathodic bias (~ 0.8V), the specimen surface oxidized to MoO2(s). With reverse bias, Mo ions were interpreted to have been removed into the glass melt. For MoSi2, Mo5Si3 interfacial layers were observed for both cathodic and anodic corrosion. Mo5Si3 debris particles (~4 µm) were seen floating into the glass en masse under a cathodic bias, but not when the bias was reversed. This was interpreted to be a result of an inherent negative charge of debris particles.
Is intraorbital fat extraorbital? Results of cross-sectional anatomy of the lower eyelid fat pads.

Background: Prominent fat pads of the lower eyelids are a frequent complaint prompting patients to seek cosmetic surgery. Previous studies have stated that these fat pads exist as three compartments in the lower eyelids. An accepted anatomic concept is that these lower eyelid fat pads are intraorbital. Objective: This study evaluates the possibility of distinct compartments of lower eyelid fat pads not being different from each other, but rather being separate from posterior intraorbital fat. Methods: This study used eight hemifacial cadaver dissections. Methylene blue injections were used to stain the middle and medial fat pads on each side. Sagittal cross-sections were obtained to visualize the area of fat staining. An axial cross-section of one additional specimen was obtained as confirmatory evidence. Results: Each specimen showed that lower eyelid fat pads stain as discrete fat compartments that are not in continuity with the posterior intraorbital fat. Their anterior boundary is the orbital retaining ligament at the anterior aspect of the inferior orbital rim. Their posterior boundary is an insertion point on the floor of the orbit in line with the midpoint of the globe, called the circumferential intraorbital retaining ligament. Conclusions: Lower eyelid fat pads are not in continuity with posterior intraorbital fat. They can accurately be described as partially intraorbital and partially extraorbital in location. This information augments our previous understanding of the anatomy of the lower eyelid fat pads and is important for studies that attempt to determine their etiology.
Configuration Interaction Effects in l N Configurations

The effects of configuration interactions on the energy-level structure of ${l}^{N}$ type configurations have been studied. In previous work the linear theory has sought to augment the usual Hamiltonian for an $N$-electron system with additional two-body scalar interactions. In the present study it is shown that by choosing suitable scalar interactions it is possible to include, to second order, all the electrostatic interactions with configurations having two electrons excited from the ${l}^{N}$ configuration. The form of the scalar interactions, together with expressions for the interaction constants in terms of the radial integrals, has been derived explicitly using perturbation theory. Effective three-body interactions are introduced to account for the perturbations due to one-electron excitations. The physical significance of the interaction constants associated with the linear theory is clarified. Formulas are given for the matrix elements of the electrostatic interaction between the ${l}^{N}$ configuration and the different species of perturbing configurations. An identity which greatly simplifies the summations arising from the second-order perturbation is established.
Spatial and temporal variability of turbulent mixing in an estuary

Observations with a microstructure/CTD profiler and an ADCP during five cruises in 1994/95 provide a glance at the turbulent mixing climate of a partially mixed estuary, the Hudson River. The cruises took place under widely varying conditions of river discharge and external forcing by water level fluctuations in New York Bight. Tidal and fortnightly variability patterns of stratification, shear and mixing characteristics were qualitatively repeatable, largely following the description of Peters (1997). (i) Longer-term variations of buoyancy frequency and Richardson number (Ri) during flood were weakly correlated with the river discharge. (ii) All flood tides had substantial mixing. Cruise-to-cruise variations of turbulent dissipation rate, salt flux, and stress were large and correlated with variations in Ri. (iii) During ebb tides, mixing was weak in response to stable stratification during neaps, and it increased dramatically toward spring tides parallel with the occurrence of low Ri. Cruise-to-cruise variations of mixing became small toward spring tide. (iv) The largest vertical salt flux occurred during spring ebbs, which provided about 30% of the total fortnightly salt flux; floods throughout the fortnightly cycle providing most of the remainder. (v) The observed level of small-scale mixing, i.e. stress and vertical salt flux, was consistent with the integral momentum and salt budgets in the uniform segment of the Hudson where the bulk of the measurements were taken. (vi) One topographically forced flow feature examined, lee waves behind a trench across the river, was associated with elevated mixing.
Weight gain in young Mongolian gerbils (Meriones unguiculatus) of mothers treated with neurotropic substances, hypoxia or electroconvulsive shock

Abstract Following single doses of neurotropics such as ethanol, phenobarbital-Na, reserpine, or haloperidol, or after short term hypoxia or electroconvulsion, retrieving in lactating Meriones unguiculatus may be severely disturbed. Mongolian gerbils were studied to see whether diminished retrieving behavior is always accompanied by reduced weight gain of the pups, also indicating the disturbance of other maternal behavior or reduced lactating. Since weight gain of the pups is not diminished following alcohol, haloperidol and reserpine, it may be concluded that the cause of reduced retrieving behavior is rather to be seen in the disturbance of higher neuronal functions than in impairment of the hormonal basis of maternal behavior.
Influence of illumination non-uniformity on pattern fidelity

As projection optics have drastically improved over time, the effects of illumination non-uniformity have a more significant impact on the pattern fidelity. For instance elliptical uniformity results in a difference in sigma for horizontal and vertical features and radial non-uniformity results in a difference in through pitch patterning. This paper specifically explores the effects of radially non-uniform illumination on through pitch imaging. Explaining how annular illumination works and showing an example of selection of annular apertures for pitch tuning will allow us to understand the effects of illumination non-uniformity on imaging through pitch for standard disk profiles. A proof that this pitch tuning, which is the overlaying of diffracted orders at a given pitch, is mathematically equivalent to strong phase shift condition at small angles will be demonstrated. Simulations with Intel Photolithography Simulation tool (iPhotoTM), using measured illumination profiles collected with a Litel Source Metrology InstrumentTM (SMI) from two different back end metal lithography tools will demonstrate that the model data fits actual wafer data on a metal interconnect process for tools with different illumination profiles. This practical example illustrates the need for lithography engineers to do sensitivity studies of layers for their process on illumination non-uniformity & to set appropriate limits on the allowable range of illumination uniformity.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Synthesis and Ultrafast Study of Cysteine- and Glutathione-Capped Ag2S Semiconductor Colloidal Nanoparticles

A new synthetic method has been developed for preparing silver sulfide, Ag2S, nanoparticles capped with cysteine or glutathione. The average particle diameter has been determined to be around 9 nm using transmission electron microscopy. The ground-state electronic absorption spectra of the Ag2S nanoparticles show a continuous increase in absorption cross section toward shorter wavelengths starting from the red (600−800 nm). Ultrafast dynamics of photoinduced electrons in these nanoparticles have been measured using femtosecond transient absorption/bleach spectroscopy. In most cases studied, the early time transient profiles feature a pulse-width limited (<150 fs) rise followed by a fast decay (750 fs) and a slower rise (4.5 ps). The signal has contribution from both transient absorption and transient bleach. On longer time scales, three (Cys-1, Cys-2, and GSH-2) of the four samples studied show a recovery with 4.5 ps time constant that goes above the baseline and then decays gradually toward the baseline ...
A note on the multiple-trace memory model without simulation

Abstract The multiple-trace memory model, MINERVA 2 ( Hintzman, 1984 , Hintzman, 1986 , Hintzman, 1988 ), has usually been examined using the computer simulation method. This article presents an analytic treatment using probability theory, leading to closed form solutions for the probability mass functions of the model distributions. The expected values of such distributions are found to relate to the model parameters in a straightforward manner. However, variances of the distributions do not appear to take on simple forms. Exact quantitative predictions of the model are greatly facilitated by the analytical results.
A theory for polarized fluorescence microscopy of chromosome structures

A theory for the determination of DNA arrangements in DNA-containing specimens, using planar aromatic dye molecules as probes for plane polarization of fluorescence, has been described. At low dye-to-DNA concentrations, the dye molecules are sandwiched between the stacked bases of DNA; hence, the fluorescence from the dye bound to a local region of DNA helix is plane-polarized with the polarization direction perpendicular to the local axis of DNA. The degree of such polarization from an aligned DNA-specimen complexed with dye is determined both by the DNA orientation and the conformational state (e.g., base tilt) of DNA into that specimen. Analysis has been made of the relationship between the degree of polarization and the orientation of the emitting dipoles of dye. The dye complexes may be aligned in a mechanical shear or electric field. However, any change in the orientation distribution of the emitting dipoles due to force fields should be taken into account. With some assumptions and approximations, the magnitude and the direction of maximum polarization can be related to different orders of DNA coiling and to their various combinations. Since the measured polarization is averaged over all DNA regions of the specimen, if the magnitude of polarization is appreciable and the polarization occurs in the specific direction of the specimen, the theory helps to eliminate several probable arrangements of DNA. The predominant molecular features of the actual DNA arrangement can be determined through this process of elimination, as explained in two subsequent papers with T-even bacteriophage and chromosome systems.
Hippocampal volume in aging combat veterans with and without post-traumatic stress disorder: Relation to risk and resilience factors

Abstract Objective To examine whether there are post-traumatic stress disorder (PTSD) related differences in hippocampal volume in middle-aged and elderly veterans and to examine the relationship of neuroendocrine activity, memory performance, and measures of risk and resilience for PTSD to hippocampal volume in this cohort. Methods Seventeen veterans with chronic PTSD and 16 veterans without chronic PTSD received an MRI scan followed by neuroendocrine assessment (24-h urinary cortisol excretion and the lysozyme IC50-DEX, a measure of glucocorticoid receptor (GR) responsiveness), and cognitive testing. Results Veterans with PTSD did not differ from those without PTSD in hippocampal volume, but they did show significantly lower urinary cortisol levels, and poorer memory performance on the Wechsler Logical Memory test and Digit Span test. Smaller left hippocampal volumes were observed in veterans who developed PTSD in response to their first reported traumatic exposure, compared to veterans who had first experienced a traumatic event to which they did not develop PTSD, prior to experiencing a subsequent event that led to PTSD. In contrast, the two neuroendocrine measures were associated with risk factors related to early trauma exposure. Conclusion Although hippocampal volume was not found to differ between subjects with and without PTSD, smaller hippocampal volumes in PTSD may be associated with specific risk and resilience factors. These may be distinct from vulnerability markers associated with increased responsiveness to glucocorticoids and/or other neuroendocrine measures that have been observed in combat-related PTSD.
A social network as information: The effect of system generated reports of connectedness on credibility on Twitter

Social media have gained increased usage rapidly for a variety of reasons. News and information is one such reason. The current study examines how system-generated cues available in social media impact perceptions of a source's credibility. Participants were asked to view one of six mock Twitter.com pages that varied both the number of followers and the ratio between followers and follows on the page and report their perceived source credibility. Data indicate that curvilinear effects for number of followers exist, such that having too many or too few connections results in lower judgments of expertise and trustworthiness. Having a narrow gap between the number of followers and follows also led to increased judgments of competence. Implications of these findings are discussed, along with limitations of the current study and directions for future research.
Spatial Variation of Soil Salinity in the Mexicali Valley, Mexico: Application of a Practical Method for Agricultural Monitoring

The degradation of irrigated lands through the process of soil salinization, or the buildup of salts in the soil, has hampered recent increases in agricultural productivity and threatens the sustainability of large-scale cultivation in critical agricultural regions of the world. Rapid detection of soil salinity on a regional basis has been identified as key for effective mitigation of such land degradation. The ability to detect regional patterns of soil salinity at an accuracy sufficient for regional-scale resource management is demonstrated using Landsat 5 Thematic Mapper (TM) imagery. A case study of the Mexicali Valley of Baja California, Mexico was selected due to the region’s agricultural significance and concern for future soil salinity increases. Surface soil salinity was mapped using georeferenced field measurements of electrical conductivity (EC), collected concurrently with Landsat 5 TM imagery. Correlations between EC measurements and common indices derived from the satellite imagery were used to produce a model of soil salinity through regression analysis. Landsat band 7, TNDVI, PCA 1, Tasseled Cap 3 and Tasseled Cap 5 were found to offer the most promising correlations with surface soil salinity. Generally low levels of soil salinity were detected, however, distinct areas of elevated surface salinity were detected at levels potentially impacting sensitive crops cultivated within the region. The difficulty detecting low levels of salinity and the mid-range spatial resolution of Landsat 5 TM imagery restrict the applicability of this methodology to the study of broad regional patterns of degradation most appropriate for use by regional resource managers.
Generalized scale-based image filtering

In medical imaging, low signal-to-noise ratio (SNR) and/or contrast-to-noise ratio (CNR) often cause many image processing algorithms to perform poorly. Postacquisition image filtering is an important off-line image processing approach widely employed to enhance the SNR and CNR. A major drawback of many filtering techniques is image degradation by diffusing/blurring edges and/or fine structures. In this paper, we introduce a scale-based filtering method that employs scale-dependent diffusion conductance to perform filtering. This approach utilizes novel object scale information via a concept called generalized ball scale, which imposes no shape, size, or anisotropic constraints unlike previously published ball scale-based filtering strategies. The object scale allows us to better control the filtering process by constraining smoothing in regions with fine details and in the vicinity of boundaries while permitting effective smoothing in the interior of homogeneous regions. Quantitative evaluations based on the Brainweb data sets show superior performance of generalized ball scale-based diffusive filtering over two existing methods, namely, ball scale-based and nonlinear complex diffusion process. Qualitative experiments based on both phantom and patient magnetic resonance images demonstrate that the generalized ball scale-based approach leads to better preserved fine details and edges.
Healing the global financial crisis

Right now, the world is in the grips of a global financial crisis. The world economy is ailing. But what are the causes of this illness, and how can we heal it? The authors take a detailed look at the history, causes, and cure of our current economic woes. © 2009 Wiley Periodicals, Inc.
Cholangiocarcinoma: Advances in pathogenesis, diagnosis, and treatment†

Cholangiocarcinoma (CCA) is an epithelial cancer originating from the bile ducts with features of cholangiocyte differentiation.1 CCA is the second most common primary hepatic malignancy, and epidemiologic studies suggest its incidence is increasing in Western countries.2 Advanced CCA has a devastating prognosis, with a median survival of <24 months.3 The only curative therapy is surgical extirpation or liver transplantation, but unfortunately the majority of patients present with advanced stage disease, which is not amenable to surgical therapies. Anatomically, CCA is classified into extrahepatic and intrahepatic forms of the disease. The extrahepatic form is more common, accounting for 80% to 90% of CCAs. It is further divided into proximal or perihilar and distal subsets depending on the location of the cancer within the extrahepatic biliary system. Perihilar disease is also frequently referred to as a Klatskin tumor. Three different growth patterns of extrahepatic CCA can be observed: (1) periductal infiltrating, (2) papillary or intraductal, and (3) mass forming.4 Intrahepatic CCA typically presents as an intrahepatic mass. In addition to their distinct morphology and clinical presentations, intrahepatic and extrahepatic CCAs differ in etiopathogenesis, molecular signatures, and management. In the last several years there have been significant new insights into the molecular pathogenesis of CCA. New diagnostic and therapeutic modalities have also been developed, resulting in improved detection rates and outcomes. In addition, we have now entered the era of targeted therapies for human cancers. Therefore, it is timely and topical to review these advances with a focus on promising targeted therapies for this disease. An additional goal is to stimulate further interest in this disease with the hope of improving outcomes for this still highly lethal malignancy.
Collision-induced dissociation of protonated MK-0991: novel ring opening of a cyclic hexapeptide in the gas phase.

Electrospray ionization tandem mass spectrometry was applied to probe the collision-induced dissociation (CID) of protonated MK-0991 {(4R,5S)-5-[(2-aminoethyl)amino]-N(2)-(10, 12-dimethyl-1-oxotetradecyl)-4-hydroxy-L-ornithyl-L-threonyl-trans -4- hydroxy-L-prolyl-(S)-4-hydroxy-(4-hydroxyphenyl)-L-threonyl-threo-3-h ydroxy-L-or-nithyl-trans-3-hydroxy-L-proline cyclic (6-1)-peptide} in the gas phase; MK-0991 is a newly developed, broad-spectrum pneumocandin antifungal drug. The study showed that protonated MK-0991 (m/z 1094) undergoes specific ring opening under the CID conditions to form two protonated linear peptides at m/z 1076 and 1034. This is different from the commonly observed ring opening of a cyclic peptide that occurs by the cleavage of the N-acyl bonds in many places on the peptide backbone. The structures of the two linear peptides were elucidated on the basis of their tandem mass spectra. The results strongly indicate that the specific ring opening of MK-0991 is affected by the ethylenediamine side-chain formed from the modification of one of the ornithine amino acids in this cyclic hexapeptide.
Effect of Grinding on Digestibility of Argentine Flint Corn

Abstract ONE of the problems which have confronted poultrymen is the question of the relative feeding values of whole and ground grains. Fields and Ford (1900), Kruger (1925), Mangold (1928), Bartlett (1910), and others have found no significant differences in digestibility due to the state of subdivision of a grain when fed. Kaupp and Ivey (1923) found slightly better digestibility for corn meal than for whole corn. The object of this investigation was to study the effect of grinding on digestibility. Argentine flint corn was selected because it is the hardest grain that is used to any extent in animal feeding. A second reason for studying this grain was that there was no information on the digestibility of Argentine flint corn in the literature. Since this grain is being used to an increasing extent in poultry feeding, more information on its feeding value was desired. MATERIAL One hundred pounds of Argentine . . .
Symmetric and nonsymmetric equilibria of a rod-and-spring model

Our aim is to demonstrate the relevance of certain general mathematical ideas and computational techniques in a comparatively simple physical example, a full appreciation of which can be intuitive. The model discussed here has two distinct reflectional symmetries, i.e. Z 2 Z 2 symmetry. The symmetry group representations, invariant subspaces, projection matrices, projected equations, and extended systems used to compute loci of singularities are all given explicitly. A closely allied nonsymmetric model is then developed and its behaviour is examined numerically
Ultrastructure of mouse and rat palatal processes prior to and during secondary palate formation

Abstract Formation of the secondary palate by the union of two palatine processes or shelves involves a series of rapid changes in the epithelial and mesenchymal shelf components. These alterations are described at the ultrastructural level just prior to, during, and after complete union. The palatal shelves exhibit an irregular outer epithelial plasmalemma which becomes more regular just prior to contact. Desmosomes form at the contacting shelf surfaces and appear to bind the two processes together until mesenchymal union is ultimately made. The newly established epithelial wall gradually breaks down, probably due to an autolytic process. Lysosome-like structures are evident within the epithelial cell cytoplasm as fragmentation of the wall proceeds. The basal lamina separating the epithelium from the mesenchyme remains intact and the underlying mesenchymal cells are unchanged until final epithelial cell disintegration occurs. Mergence rather than fusion is evident in some areas along the epithelial wall, particularly in the soft palate region where, soon after epithelial wall lysis, the basal lamina repairs across the shelves leaving a depression into the young secondary palate which is gradually reduced. Concomitantly hemi-desmosomes appear along the newly formed basal lamina.
Determination of DNA minor groove width in distamycin-DNA complexes by solid-state NMR.

We have performed solid-state 31P-19F REDOR nuclear magnetic resonance (NMR) experiments to monitor changes in minor groove width of the oligonucleotide d(CGCAAA2′FUTGGC)·d(GCCAAT(pS)TT GCG) (A3T2) upon binding of the drug distamycin A at different stoichiometries. In the hydrated solid-state sample, the minor groove width for the unbound DNA, measured as the 2′FU7–pS19 inter-label distance, was 9.4 ± 0.7 Å, comparable to that found for similar A:T-rich DNAs. Binding of a single drug molecule is observed to cause a 2.4 Å decrease in groove width. Subsequent addition of a second drug molecule results in a larger conformational change, expanding this minor groove width to 13.6 Å, consistent with the results of a previous solution NMR study of the 2:1 complex. These 31P-19F REDOR results demonstrate the ability of solid-state NMR to measure distances of 7–14 Å in DNA–drug complexes and provide the first example of a direct spectroscopic measurement of minor groove width in nucleic acids.
Continuous Biometric User Authentication in Online Examinations

Online examinations pose a unique problem for distance-based education, in that it can be very difficult to provide true user authentication. Due to the inherent anonymity of being online, compared to taking an examination in a classroom environment, students may attempt to artificially boost their scores in online examinations by having another individual take the exam for them, which a typical user/password authentication scheme cannot detect. This paper discusses and presents a method for providing continuous biometric user authentication in online examinations via keystroke dynamics.
Marijuana intoxication and brain activation in marijuana smokers

Objective and Method: The acute effects of delta9 tetrahydrocannabinol (THC) on cerebral blood flow (CBF) were studied in human subjects. Regional CBF was measured with 15O-water and Positron Emission Tomography (PET) in 32 volunteers with a history of exposure to marijuana. Scans were performed before and after intravenous (IV) infusion of either of two doses of THC or a placebo, given under double blind conditions. Results: THC but not placebo increased CBF especially in the frontal regions bilaterally, insula and cingulate gyrus and sub-cortical regions with somewhat greater effects in the right hemisphere. While most regions showed significant change at 60 minutes for the lower dose group, the higher dose group had significant change at 30 and 60 minutes. There was a highly significant change in the anterior/posterior ratio for the two THC groups reflecting minimal change in occipital flow but significant increases in frontal flow. Self ratings of THC intoxication showed significant effects, and regression analysis indicated it correlated most markedly with the right frontal region. Conclusion: Behavioral manifestations of marijuana intoxication may be associated with increased functional activity of the brain especially the frontal cortex, insula and cingulate gyrus.
Patterns of Injury, Outcomes, and Predictors of In-Hospital and 1-Year Mortality in Nonagenarian and Centenarian Trauma Patients

Importance With the dramatic growth in the very old population and their concomitant heightened exposure to traumatic injury, the trauma burden among this patient population is estimated to be exponentially increasing. Objective To determine the clinical outcomes and predictors of in-hospital and 1-year mortality in nonagenarian and centenarian trauma patients (NCTPs). Design, Setting, and Participants All patients 90 years or older admitted to a level 1 academic trauma center between January 1, 2006, and December 31, 2010, with a primary diagnosis of trauma were included. Standard trauma registry data variables were supplemented by systematic medical record review. Cumulative mortality rates at 1, 3, 6, and 12 months after discharge were investigated using the Social Security Death Index. Univariate and multivariable analyses were performed to identify the predictors of in-hospital and 1-year postdischarge cumulative mortalities. Main Outcomes and Measures Length of hospital stay, in-hospital mortality, and cumulative mortalities at 1, 3, 6, and 12 months after discharge. Results Four hundred seventy-four NCTPs were included; 71.7% were female, and a fall was the predominant mechanism of injury (96.4%). The mean patient age was 93 years, the mean Injury Severity Score was 12, and the mean number of comorbidities per patient was 4.4. The in-hospital mortality was 9.5% but cumulatively escalated at 1, 3, 6, and 12 months after discharge to 18.5%, 26.4%, 31.3%, and 40.5%, respectively. Independent predictors of in-hospital mortality were the Injury Severity Score (odds ratio [OR], 1.09; 95% CI, 1.02-1.16; P = .01), mechanical ventilation (OR, 6.23; 95% CI, 1.42-27.27; P = .02), and cervical spine injury (OR, 4.37; 95% CI, 1.41-13.50; P = .01). Independent predictors of cumulative 1-year mortality were head injury (OR, 2.65; 95% CI, 1.24-5.67; P = .03) and length of hospital stay (OR, 1.06; 95% CI, 1.02-1.11; P = .005). Cumulative 1-year mortality in NCTPs with a head injury was 51.1% and increased to 73.2% if the Injury Severity Score was 25 or higher and to 78.7% if mechanical ventilation was required. Most NCTPs required rehabilitation; only 8.9% were discharged to home. Conclusions and Relevance Despite low in-hospital mortality, the cumulative mortality rate among NCTPs at 1 year after discharge is significant, particularly in the presence of head injury, spine injury, mechanical ventilation, high injury severity, or prolonged length of hospital stay. These considerations can help guide clinical decisions and family discussions.
The Third City: Chicago and American Urbanism

The Third City: Chicago and American Urbanism, by Larry Bennett, Chicago, University of Chicago Press, 2010, 241 pp., US $22.50 (hardcover). In April 1971, Newsweek published a front cover photogra...
Development of Modeling Techniques for Damping Applications of Nano Structured Composites With High Aspect Ratio Fillers

Recent advances in the production and wide scale availability of nano scale constituents, coupled with ongoing fundamental research utilizing them as fillers in host matrices for a variety of specific engineering inquiries has led to a notable interest in the use of nano scale fillers for specific commercial applications, specifically in the aerospace industry. Damping is of particular importance in modern composites, having high stiffness and low density, damping becomes a large issue, both for structural integrity as well as noise attenuation. The largest obstacle which must first be overcome in order to incorporate the nano scale constituents in commercial applications is the development of design useful modeling and analysis techniques which allow for calculated design decisions based on constituent properties. Currently, there is a large gap in performance of nano structured composites, where in the current analysis techniques tend to overstate the performance achieved relative to experimental results. This discrepancy has been attributed to a number of factors ranging from non-perfect geometry, to issues at the interface between matrix and filler, however there has not yet been a detailed investigation to the ability to accurately predict composite viscoelastic performance based on constituent properties. On of the most common approaches to modeling high aspect ratio nano fillers, carbon nano tubes and carbon nano fibers, is to assume a perfect cylindrical geometry, even though it is well understood that these fillers can have a significant curvature or waviness to them. This investigation combines modeling work looking at the effect of the waviness and the resulting reinforcement provided, in terms of viscoelastic response, which is then compared to experimental results. Damping is characterized with respect to operating temperatures and frequency range, of specific interest is the low frequency range, which is traditionally more difficult to damp. Experimental investigations utilize dynamic mechanical analysis (DMA) to characterize viscoelastic performance, which is then compared to modeling data where it has been found that trends can be accurately predicted.Copyright © 2010 by ASME
Effect of different degrees of hypothermia on myocardium in treatment of hemorrhagic shock

Abstract The use of hypothermia in cardiac and neurologic surgery is well established, but its use in treating hemorrhagic shock is controversial. Using a modified Wiggers hemorrhagic shock model, we examined the effects of hypothermia (group 1, 33°C, N = 7; group 2, 28°C, N = 12) after inducing hemorrhagic shock. In group 3, N = 6, dogs were maintained at body temperature in hemorrhagic shock and throughout resuscitation (normothermic shock). Sixty minutes after resuscitation (shed blood and lactated Ringer's solution, 50 ml/kg body wt), all hypothermic dogs were rewarmed and studied for an additional 120 min. Comparison of moderately hypothermic, severely hypothermic, and normothermic dogs showed a lower heart rate (80.6 ± 3.3, 62.5 ± 4.1, and 136.7 ± 4.2 beats/min, P
Large deformation of isotropic biological tissue

Abstract The requirements for the development of a general potential function describing the behavior of homogeneous, isotropic biological tissue are discussed and such a function is proposed. It is shown that this function yields both tensile and torsional results compatible with existing data.
Determinants of the Commodity Composition of U.S. Trade: A Discriminant Analysis Approach

Using trade and industry data disaggregated to the four-digit S.I.C. level, the paper analyzes various hypotheses related to directions of U.S. international trade. The study concludes that capital intensity, skill intensity, and, to a lesser degree, economies of scale and industry structure are important determinants of trade patterns. Tariffs appear usually to be established against foreign industries that threaten domestic ones, but there exists limited evidence that tariffs can reverse expected directions of trade.