cssi/SciSciGPT-SciSciNet huggingface dataset:
Diffusion tensor fiber tracking of human brain connectivity: aquisition methods, reliability analysis and biological results.

We present a description, biological results and a reliability analysis for the method of diffusion tensor tracking (DTT) of white matter fiber pathways. In DTT, diffusion-tensor MRI (DT-MRI) data are collected and processed to visualize the line trajectories of fiber bundles within white matter (WM) pathways of living humans. A detailed description of the data acquisition is given. Technical aspects and experimental results are illustrated for the geniculo-calcarine tract with broad projections to visual cortex, occipital and parietal U-fibers, and the temporo-calcarine ventral pathway. To better understand sources of error and to optimize the method, accuracy and precision were analyzed by computer simulations. In the simulations, noisy DT-MRI data were computed that would be obtained for a WM pathway having a helical trajectory passing through gray matter. The error vector between the real and ideal track was computed, and random errors accumulated with the square root of track length consistent with a random-walk process. Random error was most dependent on signal-to-noise ratio, followed by number of averages, pathway anisotropy and voxel size, in decreasing order. Systematic error only occurred for a few conditions, and was most dependent on the stepping algorithm, anisotropy of the surrounding tissue, and non-equal voxel dimensions. Both random and systematic errors were typically below the voxel dimension. Other effects such as track rebound and track recovery also depended on experimental conditions. The methods, biological results and error analysis herein may improve the understanding and optimization of DTT for use in various applications in neuroscience and medicine.
A decoupled flexible‐relative co‐ordinate recursive approach for flexible multibody dynamics

An extended kinematic graph concept and a variational-vector calculus approach are employed to develop a new recursive formulation for the dynamic analysis of flexible multibody systems. The extended graph concept introduced defines frames and transformations between frames as nodes and edges, respectively, rather than the more traditional body and joint convention. Kinematic relationships between adjacent flexible bodies are derived, using joint relative co-ordinates and a state vector notation that represents both translational and rotational components of velocity. Deformation kinematics are formulated in terms of modal co-ordinates, under small deformation assumptions. Joint relative co-ordinates are decoupled from deformation modal co-ordinates in both kinematic relations and in the recursive dynamics algorithm, leading to a significant reduction in the dimension of matrices that must be inverted. Dynamic analysis of a flexible closed-loop spatial robot is performed to illustrate the efficiency of the algorithm.
Aminoglycoside antibiotics preferentially increase permeability in phosphoinositide-containing membranes: a study with carboxyfluorescein in liposomes

The rate of release from multilamellar liposomes of the fluorescent probe carboxyfluorescein was determined as a measure of membrane permeability. Liposomes of phosphatidylcholine and different anionic phospholipids were incubated with low (1 microM) and high (3 mM) concentrations of calcium in the absence or presence of aminoglycoside antibiotics. The leakage of carboxyfluorescein into the medium was not caused by liposomal fusion as no vesicle fusion was observed in experiments with terbium and dipicolinic acid-loaded liposomes. The basal rate of carboxyfluorescein release (in the absence or presence of 1 microM calcium) from all types of liposomes ranged from 0.1 to 0.3% of trapped carboxyfluorescein per hour. The presence of 3 mM calcium caused the greatest increase in the rate of carboxyfluorescein release (about 9-fold) in liposomes containing phosphatidylinositol 4,5-bisphosphate (PIP2) whereas liposomes containing the other anionic phospholipids (phosphatidylserine, phosphatidylinositol and phosphatidylinositol 4-phosphate) showed an approximate 5-fold increase. In the presence of 1 microM calcium, the aminoglycosides neomycin and gentamicin also increased the rate of carboxyfluorescein release, with PIP2-containing liposomes showing a 3-5-times greater response than the other liposomes, releasing up to 4.6% of trapped carboxyfluorescein per hour. This drug-induced release was dose-dependent and antagonized by calcium. In the presence of 3 mM calcium, 0.1 mM gentamicin or neomycin were ineffective while the drug at 1 mM affected carboxyfluorescein release from PIP2-liposomes only. The aminoglycoside antibiotics, neomycin, gentamicin, tobramycin, kanamycin, amikacin, netilmicin, as well as neamine and spectinomycin (all at 0.1 mM) showed a graded effect on the rate of carboxyfluorescein release from PIP2-containing vesicles in the presence of 0.1 mM calcium. The magnitude of the effect correlated well with the ototoxicity of the drugs previously determined directly in cochlear perfusions in the guinea pig. The study demonstrates that aminoglycoside antibiotics are capable of altering membrane permeabilities and that this effect is most pronounced if PIP2 is present in the bilayers. The excellent correlation between this membrane action and the in-situ toxicity of the drugs further establishes the specific role of PIP2 in the molecular mechanism of aminoglycoside-induced hearing loss. Moreover, it confirms the usefulness of such physicochemical models for the screening and prediction of aminoglycoside toxicity.
Structural health monitoring and nondestructive evaluation of double wall structures

Double wall structures are three-layered systems in which the second or intermediate layer is frequently a liquid. The liquid aids in the cooling process when the interior is at high temperature. Examples are double wall steam pipes, pressure vessels and heat exchanger plates. Structural health monitoring and nondestructive testing from the outside, through three layers to the inside wall is difficult. This paper presents a viable solution by proposing the use of ultrasonics to generate a slow guided wave in the structure enabling inspection of the inner wall for flaws. The results of calculations, simulations and experiments are presented and compared. In particular, a two-dimensional model of the setup is introduced and a procedure for obtaining group velocity dispersion diagrams. The model is validated using theoretical and experimental results. Sample dispersion diagrams are presented and compared with those obtained with matrix methods. Finally, the FEM simulation results depict the displacement profiles across the waveguide. The results of both modeling techniques are in good agreement and they provide interesting insights into the wave mechanics of the three-layered waveguide.
Effects of postoperative epidural analgesia on recurrence-free and overall survival in patients with nonsmall cell lung cancer ☆

Abstract Study Objective To determine whether postoperative epidural analgesia is associated with better recurrence-free survival and overall survival after lung cancer surgery. Design Retrospective study. Setting Academic hospital. Measurements Data of patients with stage 1, stage 2, and stage 3 nonsmall cell lung cancer, who underwent tumor resection surgery, were studied. Patient data were grouped into three different postoperative pain management interventions: intravenous patient-controlled analgesia, patient-controlled epidural analgesia, and their combination. Univariate and multicovariate Cox proportional hazards models were applied to assess the effects of covariates of interest on overall survival and recurrence-free survival. Main Results The type of postoperative analgesia used for patients who underwent surgery for nonsmall cell lung cancer did not affect recurrence-free survival or overall survival. However, certain variables, including age ≥ 65 years, male gender, body mass index ≥ 25 kg/m 2 , ASA physical status 4, and the need for preoperative blood transfusions, pneumonectomy, and postoperative radiation, were associated with decreased recurrence-free survival and overall survival. Conclusions The type of postoperative analgesia used after surgery for nonsmall cell lung cancer is not associated with better 2-year or 5-year recurrence-free survival or overall survival rates.
Structural Stability in Models of American Trade Union Growth

Recent interest in trade union activity has led to the development of econometric models of union membership growth. This paper examines the structural stability of two of the leading models—Ashenfelter-Pencavel's and Bain-Elsheikh's—each of which claimed to have captured the primary determinants of union growth in the twentieth century. The models were reestimated using revised, corrected, and extended membership data, and a nonlinear, maximum-likelihood procedure was employed to estimate the shift-point for each model. Contrary to previous studies, we found evidence of a break in the structure of each model. And unlike earlier work that hypothesized a World War II break-point, our estimated point was 1937–1938, most likely reflecting the impact of the Wagner Act.
A nonlinear extension of the RPA and its application to the even nickel isotopes

Abstract A nonlinear extension of the RPA is proposed and applied to calculate anharmonic effects in the even nickel isotopes. It is shown, by comparison with an exact diagonalization, to be highly accurate.
Effects of vasodilators on pulmonary hemodynamics and gas exchange in left ventricular failure

Abstract Nitroprusside (NP) has been shown to improve left ventricular function in patients with congestive heart failure, but despite an increased cardiac output and decreased pulmonary capillary pressure, arterial oxygen tension (P a O 2 ) may fall. In order to determine the mechanism of this hypoxemia, and to determine if similar effects occur with non-parenteral vasodilators, hemodynamic, respiratory, and blood gas responses to NP, hydralazine (H), and hydralazine combined with isiosorbide dinitrate (H+N) were studied in 10 patients with left ventricular failure. At the dosages used, all three drug regimens increased cardiac output equivalently, but pulmonary vascular responses differed. NP and H+N decreased mean pulmonary artery pressure, pulmonary wedge pressure, and pulmonary arteriolar resistance, while H did not. NP decreased P a O 2 by 10.4 mm. Hg (p a O 2 . Arteriolar-alveolar oxygen gradient increased with NP (150 ± 39 per cent, p a O 2 . Changes in arteriolar-alveolar oxygen gradient correlate with the changes in pulmonary arteriolar resistance. Thus vasodilators which have prominent pulmonary vascular effects can decrease P a O 2 in patients with congestive heart failure, and this effect is most likely due to increasing ventilation-perfusion inequities.
Electrochemical characterization of carbohydrate oxidation at copper electrodes

Abstract The electrochemical oxidation of carbohydrates at copper electrodes in alkaline solution is studied by cyclic voltammetric and rotating ring-disk electrode experiments. It is demonstrated herein that an important step in the oxidation of carbohydrates is their interaction with the oxide/hydroxide layer covering the electrode. This interaction is believed to involve the Cu(I) oxidation state although interaction with Cu(II) may also occur once it is formed. The extent of this interaction is measured by the decrease in peak height and electrochemical charge under the Cu(II) formation wave, and is sugar dependent. It is interesting that there is a correspondence between the extent of the interaction and the oxidative charge measured between 0.4 and 0.6 V (Ag/AgCl reference electrode) in the presence of carbohydrates. Structural effects may be influencing the interaction between carbohydrates and the electrode surface. The oxidation of many carbohydrates occurs in the potential region corresponding to the formation of Cu(III). Rotating ring disk electrode experiments strongly suggest that Cu(III) plays an important role in carbohydrate oxidation after the adsorption step. The electrooxidation of glucose at copper electrodes in alkaline solutions goes beyond the formation of gluconic acid (two electron transfer). Further oxidation may continue through CC bond cleavage. A mechanism for the oxidation of carbohydrates at copper electrodes is proposed. The mechanism includes the formation of complex species between the carbohydrates and the copper.
Technologies for low radio frequency observations of the Cosmic Dawn

The Jet Propulsion Laboratory (JPL) is developing concepts and technologies for low frequency radio astronomy space missions aimed at observing highly redshifted neutral Hydrogen from the Dark Ages. This is the period of cosmic history between the recombination epoch when the microwave background radiation was produced and the re-ionization of the intergalactic medium by the first generation of stars (Cosmic Dawn). This period, at redshifts z > ∼20, is a critical epoch for the formation and evolution of large-scale structure in the universe. The 21-cm spectral line of Hydrogen provides the most promising method for directly studying the Dark Ages, but the corresponding frequencies at such large redshifts are only tens of MHz and thus require space-based observations to avoid terrestrial RFI and ionospheric absorption and refraction. This paper reports on the status of several low frequency technology development activities at JPL, including deployable bi-conical dipoles for a planned lunar-orbiting mission, and both rover-deployed and inflation-deployed long dipole antennas for use on the lunar surface. In addition, recent results from laboratory testing of low frequency receiver designs are presented. Finally, several concepts for space-based imaging interferometers utilizing deployable low frequency antennas are described. Some of these concepts involve large numbers of antennas and consequently a large digital cross-correlator will be needed. JPL has studied correlator architectures that greatly reduce the DC power required for this step, which can dominate the power consumption of real-time signal processing. Strengths and weaknesses of each mission concept are discussed in the context of the additional technology development required.
SU‐E‐T‐10: A Computational Model for the Estimation of Biological Dose in a Clinical Proton Beam

Purpose: The variability of relative biological effectiveness (RBE) of a proton beam with spatial distribution is well known. It is dependent on the proton beam characteristics, type of tissue and biological indices. A computational model based on a proton spectrum and LET is used for the estimation of the biological dose. Methods: The depth dose curve of the pristine beam is divided into two regions: the proximal region from the surface to the Bragg peak and the distal region beyond the peak. Knowing the beam energy at the surface in the proximal region, and using the published energy‐range tables, we estimated the effective proton energy at any depth proximal to the Bragg peak. Based on the energy, the LET and RBE is estimated. In the distal region, we assume that the effective beam energy changes monotonically from the value calculated at the peak to the final energy of about 3MeV at the 3% dose level on the distal edge. Applying the calculated RBE factor to the measured depth dose profile we obtain the biological dose in the pristine beam. The method can easily be applied to modulated beams. Results: Our computation model shows that it is possible to predict the biological dose for any combination of beam energy, and for SOBP size based on the available RBE data. Our results showed that the biological dose for a SOBP has finite slope rising to higher values close to distal edge of the peak. Conclusions: A computational model provides an unique tool to estimate the biological dose in any combination of beam energy and SOBP size. If the RBE vs LET data for a tissue is know our computational approach could provide the biological dose accurately in a clinical beam.
A new genus, Khasianthus, from India, Myanmar, and China (Vernonieae: Asteraceae)

Abstract A new Asian genus of Vernonieae, Khasianthus, is named for Vernonia subsessilis DC. It is most closely related to the primarily African genus Baccharoides Moench.
Enzymatic addition of modified cytosine nucleotides to DNA Methacrylate polymerization by an azo pyrimidine

An azo pyrimidine that induces the polymerization of 1-glyceryl methacrylate has been prepared. 1-Glyceryl methacrylate contains substituent glycol groups for binding heavy atoms for subsequent electron microscopic studies. Oxodation of 1-methyl N4-ureidocytosine (compound 1A) with N-bromosuccinimide produced 4-aminocarbonylazo-2-pyrimidinone (compound 2A). This orange compound shows a broad peak (lambda max = 349 nm) in its ultraviolet absorption spectrum. Mixing compound 2A with mildly acidic aqueous solutions of 1-glyceryl methacrylate (pH 3.6) resulted in polymerization of the methacrylate. Under these conditions, the ester 1-glyceryl methacrylate does not hydrolyze appreciably as judged by oxidation of the glycol groups with NaIO4 and spectrophotometric analysis of the HCHO liberated using Schiff's reagent. Attachment of azo nucleotides to the 3'-terminus of DNA was achieved in two steps. First, N4-ureidocytosine deoxynucleotides were enzymatically added to single strand DNA primers using calf thymus terminal deoxynucleotidyl transferase, Co2+, and N4-ureido-2'-deoxycytidine 5'-triphosphate (prepared by the HSO3--catalyzed transamination reaction of dCTP with semicarbazide). Second, these modified nucleotides were oxidized with N-bromosuccinimide to produce DNA that contained azo pyrimidine nucleotides at its 3'-end (azoDNA). Upon adding acid to the azoDNA, the azo nucleotides decomposed. If these nucleotides induce methacrylate polymerization upon decomposition as did compound 2A, it may be possible to mark the location of DNA termini in situ for electron microscopy by attaching heavy atoms to the poly(1-glyceryl methacrylate) formed. Such studies may elucidate the nature and location of the ends of the eukaryotic chromosomal DNA molecule in both chromosomes and interphase nuclei.
In vitro degradation behavior of freeze-dried carboxymethyl-chitin sponges processed by vacuum-heating and gamma irradiation

Abstract Freeze-dried carboxymethyl-chitin (CM-chitin) sponges were processed by heat-treatment in a vacuum at 120–160 °C to endow biological stability for use as biomaterials. The sponges were also sterilized by gamma-irradiation (25 kGy). The in vitro degradation behavior of these sponges was evaluated in phosphate-buffered saline (PBS) or 10 μg/ml of lysozyme in PBS at 37 °C. Stability to enzymatic hydrolysis of the sponges was increased with increasing temperature in processing, whereas gamma irradiation increased the degradation ratio of sponges. The results of X-ray diffraction (XRD) for constructs and gel permeation chromatography (GPC) for extracts of the sponges suggested that the stabilities of the CM-chitin sponges basically depended not on crystallinity but on three-dimensional crosslinkage of CM-chitin molecules. These findings indicated that the biodegradability properties of CM-chitin sponge could be controlled by post-molding treatment involving vacuum-heating and gamma irradiation.
Neurohormonal modulation of rat enterochromaffin-like cell histamine secretion

Abstract BACKGROUND & AIMS: Gastric mucosal cells and nerve terminals contain at least acetylcholine, adrenergic agents, vasoactive intestinal polypeptide, calcitonin gene-related peptide, substance P, serotonin, gamma-amino-butyric acid, neurokinins A and B, neurotensin, neuropeptide Y, peptide YY, gastrin-releasing peptide, somatostatin, and [Met5]enkephalin. Although some of these agents have been implicated as regulators of gastric acid secretion, their site and mechanism of action is not well understood. The aim of this study was to investigate whether local gastric neurotransmitters modulate acid secretion by regulating basal and gastrin-driven enterochromaffin-like (ECL) cell histamine release. METHODS: The effects of the above agents were investigated in a short-term 90%-95% pure ECL cell culture system. Cells were incubated with either the neuromodulator alone or in combination with gastrin for 10-40 minutes, and histamine secretion was measured by enzyme immunoassay. RESULTS: Acetylcholine, isoproterenol, and vasoactive intestinal polypeptide significantly stimulated basal and gastrin-driven histamine secretion, whereas calcitonin gene-related peptide and somatostatin inhibited basal and gastrin-driven histamine secretion. The M1 muscarinic receptor antagonist pirenzepine dose dependently inhibited the action of acetylcholine, whereas the M3 receptor antagonist 4-diphenylacetoxy-N-(2-chloroethyl)-piperidine hydrochloride had no effect. the rest of the evaluated agents had no effect on ECL cell histamine secretion. CONCLUSIONS: These data are consistent with the hypothesis that substantial neurohormonal modulation of ECL cell function exists. (Gastroenterology 1996 Apr;110(4):1084-92)
Pneumococcal Pericarditis: Diagnostic Usefulness of Counterimmunoelectrophoresis and Computed Tomographic Scanning

• Although counterimmunoelectrophoresis (CIE) analysis of cerebrospinal fluid has proved useful in the diagnosis of meningitis, there has been little experience with its use in analyzing pericardial fluid. We describe two patients with pneumococcal pneumonia whose hospital course was complicated by purulent pericarditis. In one patient, results of a computed tomographic scan were important in suggesting the diagnosis. Results of a Gram's stain and culture of pericardial fluid failed to yield any organisms, presumably because both patients had received nine days of β-lactam antibiotic therapy. However, the results from CIE analysis of pericardial fluid in both cases were positive forStreptococcus pneumoniae. In one patient, for whom capsular typing of the organism was performed, the pneumococcus type isolated from pericardial fluid matched the type isolated previously from a blood sample. The results of CIE can allow focused antibiotic therapy by establishing the correct diagnosis. (Arch Intern Med1986;146:1174-1176)
Not "just" a coincidence: frontal-striatal interactions in working memory and interval timing.

The frontal cortex and basal ganglia play central roles in working memory and in the ability to time brief intervals. We outline recent theoretical and empirical work to suggest that working memory and interval timing rely not only on the same anatomic structures, but also on the same neural representation of a specific stimulus. Specifically, cortical neurons may fire in an oscillatory fashion to form representations of stimuli, and the striatum (a basal ganglia structure) may detect those patterns of cortical firing that occur co‐incident to important events. Information about stimulus identity can be extracted from which cortical neurons are involved in the representation, and information about duration can be extracted from their relative phase. The principles derived from these biologically based models also fit well with a family of behaviourally based models that emphasise the importance of time in many working memory phenomena.
In hypertension, the kidney is not always the heart of the matter

Blood pressure abnormalities are thought to originate from intrinsic changes in the kidney, a concept that has been largely unchallenged for more than 4 decades. However, recent molecular, cellular, and transgenic mouse studies support an alternative hypothesis: primary abnormalities in vascular cell function can also directly cause abnormalities of blood pressure. In this issue of the JCI, Crowley and coworkers describe the application of an elegant cross-renal transplant model to type 1A angiotensin (AT1A) receptor–deficient mice and their wild-type littermates to explore the relative contributions of renal and extrarenal tissues to the low blood pressure seen in the AT1A receptor–deficient animals. Their studies further support the emerging paradigm that primary abnormalities of the vasculature can make unique, nonredundant contributions to blood pressure regulation; the findings have potentially important implications for the ways we diagnose and treat blood pressure diseases in humans.
A subnanosecond time discriminator system

Abstract A time discriminator is described, which gives an output if two pulses on separate input lines (which overlap) have their leading edges separated by a time greater than a preset value. Three channels are packaged in a single-width NIM module. Also described is a digitally controlled delay circuit used in calibration of the discriminator. The time discriminator provides 200 ps resolution, 60 ns (15 MHz) double pulse resolution, better than 1% linearity over a 20 ns range, and ECL and NIM outputs with adjustable width control.
Two Unusual Episodes of ≈13-Day Variations II. Implications for the Solar Radio Flux Density, F 10.7 cm

Additional analysis of the behavior of the international sunspot number (R) series and the solar radio flux density (F10.7 cm) series during two long (250–500 days) and distinct episodes of persistent ≈13-day variations (Crane, Solar Phys. 1998, 253, 177) is reported. The conclusion is that while the center-to-limb behavior of R does not change between solar minimum and solar maximum, F10.7 cm exhibits significantly less limb brightening at solar maximum than at solar minimum.
Prospective analysis of presenting symptoms among 265 patients with radiographic evidence of Chiari malformation type I with or without syringomyelia.

Objective To characterize the presenting symptoms among persons with radiographic evidence of Chiari malformation (CM) type I in an effort to help the primary care provider determine accurate diagnosis and treatment. Methods The symptoms of CM can often be vague and ambiguous, leading to misdiagnosis. Patients who had radiographic evidence of CM with or without syringomyelia were prospectively studied. The detailed symptom data were collected from patient reports at initial examination to determine if there was a pattern of symptoms typically attributable to the CM. Results Analysis of presenting symptoms among 265 patients demonstrated a distinct pattern of symptom constellation. This study reports a prospective analysis of presenting symptoms among 265 patients with radiographic evidence of CM with or without syringomyelia and defines a common presentation pattern. Recognition of typical symptoms attributable to CM can result in appropriate diagnostic workup, accurate diagnosis, and timely treatment, leading to improved patient outcomes.
Bilateral inferior shoulder dislocation.

A 42-year-old male with a history of multiple shoulder dislocations presented to the emergency department via emergency medical services with both arms locked above his head, stating that he had been jumped at a bar and had since been unable to move his arms. A single anteroposterior chest radiograph (Figure) demonstrates bilateral inferior shoulder dislocations. The humeral head (white arrow) is displaced from the glenoid (yellow arrow) on each side. Figure Radiograph of bilateral inferior shoulder dislocations. Humeral head (white arrow), displacement from glenoid (yellow arrow). Inferior shoulder dislocations are the rarest of all glenohumeral joint dislocations, accounting for less than 1%; and bilateral inferior dislocations are therefore extremely infrequent. The classic presentation is the patient whose arm is locked above his head in a hyper-abducted fashion. The inferior dislocation must first be converted to an anterior dislocation by slowly adducting the arm. The anterior dislocation can then be reduced using routine maneuvers. In our case the patient underwent reduction with propofol sedation and was placed in bilateral shoulder slings. He was observed overnight by the orthopedic service for ethanol metabolism and was safely discharged home the next day in bilateral arm slings.
Forensic utility of isotope ratio analysis of the explosive urea nitrate and its precursors

Urea nitrate (UN) is an improvised explosive made from readily available materials. The carbon and nitrogen isotope composition of UN and its component ions, urea and nitrate, could aid in a forensic investigation. A method was developed to separate UN into its component ions for δ(15)N measurements by dissolving the sample with KOH, drying the sample, followed by removal of the urea by dissolution into 100% methanol. UN was synthesized to assess for preservation of the carbon and nitrogen isotope compositions of reactants (urea and nitric acid) and product UN. Based on nitrogen isotope mass balance, all UN samples contained varying amounts of excess nitric acid, making the ionic separation an essential step in the nitrogen isotope analysis. During UN synthesis experiments, isotopic composition of the reactants is preserved in the product UN, but the urea in the product UN is slightly enriched in (15)N (<1‰) relative to the reactant urea. Published isotopic compositions of UN reactants, urea and nitric acid, have large ranges (urea δ(15)N = -10.8 to +3.3‰; urea δ(13)C = -18.2 to -50.6‰; and nitric acid δ(15)N = -1.8 to +4.0‰). The preservation of isotopic composition of reactants in UN, along with a significant variability in isotopic composition of reactants, indicates that isotope ratio analysis may be used to test if urea or nitric acid collected during an investigation is a possible reactant for a specific UN sample. The carbon and nitrogen isotope ratios differ significantly between two field-collected UN samples, as well as the lab-synthesized UN samples. These observed variations suggest that this approach is useful for discriminating between materials which are otherwise chemically identical.
Time‐resolved IR studies of α‐lactones

A series of α-lactones were generated from the reaction of phenylchlorocarbene, 4-nitrophenylchlorocarbene, diphenylcarbene, bis(4-nitrophenyl)carbene and bis(4-methoxyphenyl)carbene with carbon dioxide and examined by nanosecond time-resolved infrared (TRIR) spectroscopy. Estimated second-order rate constants for the reaction of these carbenes with carbon dioxide indicate that more nucleophilic carbenes react at faster rates, in agreement with previous low-temperature matrix experiments. Spectral TRIR data confirms that the structure of α-lactones is dependent both on substituents at the α-carbon and on solvent polarity, with electron-donating substituents and polar solvents favoring a zwitterionic ring-opened structure as opposed to the three-membered ring oxiranone form. B3LYP calculations using self-consistent reaction field (SCRF) methods also provide support for these experimental investigations. Copyright © 2004 John Wiley & Sons, Ltd.
Participation in maternal serum screening following screen positive results in a previous pregnancy

Objective—To determine whether women who have had a positive serum screening result in one pregnancy have a lower rate of participation in screening in their next pregnancy. Setting—The Women and Infants Hospital triple marker screening programme. Methods—Pregnancy and screening information was collected from laboratory and hospital databases to compare subsequent screening participation in women who were screen negative and screen positive for risk of Down’s syndrome (DS) or neural tube defect (NTD) pregnancy. Results—In an age matched comparison, 108 women who had a previous screen positive result were significantly less likely than 108 women who were screen negative to participate in maternal serum screening in their next pregnancy. When examined according to type of screen positive result, the eVect was significant for both those who were screen positive for DS and those who were screen positive for NTD. The degree of risk in screen positive women did not significantly aVect their uptake of screening in the next pregnancy. Conclusions—Anxiety related to a screen positive result probably causes decreased participation in maternal serum screening in the next pregnancy. Reducing the screen positive rate in prenatal serum screening would alleviate maternal anxiety and would probably lead to more stable participation. (J Med Screen 2000;7:4‐6)
Keeping up with survivors: education across the spectrum of cancer.

The Institute of Medicine (IOM) report: From Cancer Patient to Cancer Survivor: Lost in Transition,1 clearly articulated a need for cancer education programs addressing survivorship. Even earlier in the 1980’s, the American Association of Cancer Education (AACE) recommended improving cancer education in United States medical schools.2 Disappointingly, a follow-up survey done a decade later demonstrated little progress.3 AACE recommendations included a national cancer education curriculum; improved instructional materials, methods and evaluation tools; and an ongoing funding process to provide support for educational activities, with a shift in emphasis to include more on topics of prevention, early diagnosis, tumor biology, rehabilitation, palliative care and psychosocial issues.4
Postflight Behavior of the Greenbug, Schizaphis graminum (Homoptera: Aphididae), in the Laboratory

Schizaphis graminum (Rondani) which had flown for 30 sec, 5 min, and 10 min were forced to land but not prevented from taking off again. The duration of flight had no significant effect on the time until 2nd takeoff. Greenbugs that landed on barley took off after a longer interval than did those that landed on broad bean or dried barley. Of the greenbugs held on broad bean, 100% took off after a 4-hr holding period, while the maximum takeoff from barley was 15%. Compared with nonflown controls, greenbugs which flew for 2 min had (1) greater rate of muscle histolysis, (2) greater rate of reproduction in first 6 days of adult life, (3) lower mortality on a host plant, but higher mortality when starved, and (4) greater reproduction potential per adult.
Developmental immunotoxicology (DIT): windows of vulnerability, immune dysfunction and safety assessment

Developmental immunotoxicity (DIT) is an increasing health concern since DIT outcomes predispose children to those diseases that have been on the rise in recent decades (e.g., childhood asthma, allergic diseases, autoimmune conditions, childhood infections). The enhanced vulnerability of the developing immune system for environmental insult is based on unique immune maturational events that occur during critical windows of vulnerability in early life. The semi-allogeneic pregnancy state, with suppression of graft rejection and associated skewing of the fetal and neonatal immune system, also influences the specific nature of DIT outcomes. In the exposed offspring, targeted immunosuppression can co-exist with an increased risk of allergic and/or autoimmune disease. Because with DIT immune dysfunction rather than profound immunosuppression is the greater concern, testing approaches should emphasize multi-functional assessment. Beyond T-cells, dendritic cells and macrophages are sensitive targets. The last-trimester fetus and the neonate are normally depressed in T(H)1-dependent functions and postnatal acquisition of needed T(H)1 capacity is a major concern with DIT. With this in mind, assessment should include a measure of T(H)1-dependent cell-mediated immunity [cytotoxic T-lymphocyte (CTL) activity or delayed-type hypersensitivity (DTH) response] in conjunction with a multi-isotype T-dependent antibody response (TDAR) and evaluation of innate immunity (e.g., NK activity). Other parameters such as immune histology, immunophenotyping, cytokine responses, and organ weights can be useful when included with immune functional evaluation. A multifunctional DIT protocol using influenza challenge is presented as one example of an approach that permits dysfunction and misregulation to be evaluated.
Organic anxiety syndrome secondary to metastatic brain tumor.

A nxiety is a ubiquitous emotional complaint, and anxiety disorders are among the most prevalent psychiatric illnesses in the United States.’ Endogenous anxiety, particularly in the severe form of panic disorder, can generate an intense and urgent need in the afflicted person for explanation and relief. The panic attack itself involves enhanced autonomic arousal, possibly referable to activation of brainstem nuclei,2 and it produces predominantly physical symptoms. Many patients seek multiple consultations and undergo unnecessary medical evaluations, often redundant and costly.3 In contrast, an unknown fraction of anxiety states will have a specific organic etiology. Recognition of this has led to inclusion of organic anxiety syndrome in the DSM-III-R, and consideration of this diagnostic possibility should be part of each evaluation. Endocrine disorders are most commonly cited as potential causes of organic anxiety states. Brain tumor is sometimes mentioned in the literature, and several isolated cases with primary neoplasm associated with panic attacks have been reported.4 We report a case of a middle-aged woman who presented with recent onset of typical panic attacks and who showed a positive response to imipramine therapy, but whose anxiety probably was secondary to focal brain lesions and/or cerebral edema associated with metastatic disease.
Does Crime Pay? Issue Ownership, Political Opportunity, and the Populist Right in Western Europe

This article contributes to the vast literature concerning extreme right parties in Western Europe by examining the effects of crime on the electoral success of these parties. Utilizing theories of...
Response to Letter by Makris et al Regarding Article, “Carotid Artery Stenting Versus Carotid Endarterectomy: A Comprehensive Meta-Analysis of Short-Term and Long-Term Outcomes”

Response: We would like to thank Makris et al for their constructive comments regarding our recent meta analysis.1 Indeed, information regarding carotid plaque stability, statin administration protocols, detection of microembolic signals using transcranial doppler monitoring,2 as well as carotid and aortic arch anatomy have not been systematically examined by the individual studies. Rather expectedly, the meta analysis reflects the limitations of the existing literature. Regarding the notion of symptomatic/asymptomatic patients, we agree that the majority of subjects included in this meta analysis were symptomatic. Specifically, …
Local suppression of epileptiform activity by electrical stimulation in rat hippocampus in vitro.

High frequency electrical stimulation of deep brain structures (DBS) has been effective at controlling abnormal neuronal activity in Parkinson's patients and is now being applied for the treatment of pharmacologically intractable epilepsy. The mechanisms underlying the therapeutic effects of DBS are unknown. In particular, the effect of the electrical stimulation on neuronal firing remains poorly understood. Previous reports have showed that uniform electric fields with both AC (continuous sinusoidal) or DC waveforms could suppress epileptiform activity in vitro. In the present study, we tested the effects of monopolar electrode stimulation and low-duty cycle AC stimulation protocols, which more closely approximate those used clinically, on three in vitro epilepsy models. Continuous sinusoidal stimulation, 50 % duty-cycle sinusoidal stimulation, and low (1.68 %) duty-cycle pulsed stimulation (120 μs, 140 Hz) could completely suppress spontaneous low-Ca2+ epileptiform activity with average thresholds of 71.11 ± 26.16 μA, 93.33 ± 12.58 μA and 300 ± 100 μA, respectively. Continuous sinusoidal stimulation could also completely suppress picrotoxin- and high-K+-induced epileptiform activity with either uniform or localized fields. The suppression generated by the monopolar electrode was localized to a region surrounding the stimulation electrode. Potassium concentration and transmembrane potential recordings showed that AC stimulation was associated with an increase in extracellular potassium concentration and neuronal depolarization block; AC stimulation efficacy was not orientation-selective. In contrast, DC stimulation blocked activity by membrane hyperpolarization and was orientation-selective, but had a lower threshold for suppression.
Single Crystal Plasticity Finite Element Analysis of Cu6Sn5 Intermetallic

Due to the miniaturization of the solder joints in micro/nanoelectronic devices, the volume ratio of intermetallic (IMCs) materials has substantially increased. This increased ratio could affect the reliability of solder joints depending on the regime and the rate of the loading. Cu6Sn5 is the primary IMC layer in the solder joint, and the primary crack initiation is observed in Cu6Sn5 site in the literature. As the size of the joints becomes closer to the grain size, joints may only contain a few numbers of grains of Cu6Sn5. This manifests itself in statistical grain size effects, as well as anisotropy. Modeling these joints using bulk properties of Cu6Sn5 does not capture the actual behavior of these joints especially when plastic deformation is involved. Plastic deformation, starting at yield point, happens to be associated with the activation of slip systems. Deformation of a slip system of single crystal largely rests on the slip parameters such as critical resolved shear stress (CRSS), initial hardening modulus, and saturation stress (Stage I stress when large plastic flow occurs). However, no efforts have been made to capture the slip parameters of Cu6Sn5 experimentally or analytically because of the difficulties of using conventional mechanical tests to measure the slip parameters of HCP single crystals. Due to wide range of CRSS values, it becomes difficult to isolate a specific slip system in testing without activating the other slip systems. The crystal plasticity finite-element (CPFE) method takes into account the effect of anisotropy and slip system behavior in modeling materials. This work uses a combined strategy based upon experiments, modeling, and a comparative analysis to obtain slip system parameters that could predict the slip process of Cu6Sn5. Nanoindentation tests were performed on Cu6Sn5 single crystal to extract the load–displacement curves, and a CPFE nanoindentation model analysis along with custom user material was utilized to obtain set of crystal plasticity material parameters which can represent the plastic behavior of Cu6Sn5 IMC. These parameters were then used to predict shear yield strength and shear modulus of Cu6Sn5, and the findings were compared with the previously published values in the literature.
Sacrificial bonds and hidden length in biomaterials: A kinetic constitutive description of strength and toughness in bone

Sacrificial bonds and hidden length in structural molecules account for the greatly increased fracture toughness of biological materials compared to synthetic materials without such structural features by providing a molecular-scale mechanism for energy dissipation. One example is in the polymeric glue connection between collagen fibrils in animal bone. In this paper we propose a simple kinetic model that describes the breakage of sacrificial bonds and the release of hidden length, based on Bell's theory. We postulate a master equation governing the rates of bond breakage and formation. This enables us to predict the mechanical behavior of a quasi-one-dimensional ensemble of polymers at different stretching rates. We find that both the rupture peak heights and maximum stretching distance increase with the stretching rate. In addition, our theory naturally permits the possibility of self-healing in such biological structures.
Egelhoff, ERISA Preemption, and the Conundrum of the 'Relate To' Clause

In this article, Professor Zelinsky discusses the recent decision of the United States Supreme Court in Egelhoff v. Egelhoff. In Egelhoff, the Court held that section 514(a) of the Employee Retirement Income Security Act of 1974 (ERISA) preempts a Washington state statute under which, as to nonprobate assets, divorce revokes any pre-divorce beneficiary designation of the former spouse. Egelhoff, Professor Zelinsky contends, indicates that the Court, in the midst of revising its earlier understanding of section 514(a) and of ERISA's preemptive effect, has yet to settle on a construction of section 514(a) and its expansive terminology. Professor Zelinsky suggests that in the wake of Egelhoff, the best reading of section 514(a) and its "relate to" test is to treat them as a statutory presumption for preemption in the ERISA context. The alternative - construing section 514(a) as incorporating the Court's normal standards of preemption - has serious logical and textual limitations. In contrast, treating the "relate to" clause as a presumption for preemption provides a convincing rationale for the result in Egelhoff and comports well with the terminology of the statute. Moreover, such an approach supplies solid footing for the more restrained outlook on ERISA preemption the Supreme Court has embraced since its decision in New York State Conference of Blue Cross & Blue Shield Plans v. Travelers Insurance Co.
Topochemical Effects in Chemical Reactions of Crystalline Organic Compounds

A topochemical effect in a solid state reaction is any effect on the structure and properties of the product or the kinetics of the reaction that can be directly attributed to the geometric arrangement of the reacting groups or the distance between those groups. Such effects can conveniently be classified in three catagories: (a) Reactions in which the reactant and product form solid solutions over the entire range of compositions, (b) Reactions in which the product phase is nucleated but a crystallographic relationship between the reactant and product phases is maintained. (c) Reactions which result in an amorphous product or crystalline product having no crystallographic correlation with the reactant.
Response to immunotherapy in a patient with Landau-Kleffner syndrome and GRIN2A mutation

Landau-Kleffner syndrome (LKS) has been demonstrated in the past to respond to immunotherapy. Recently, some cases of LKS have been shown to be secondary to glutamate receptor (GRIN2A) mutations. Whether such cases respond to immunotherapy is not known. Here, we present the case of a 3-year-old boy with LKS found to have a GRIN2A heterozygous missense mutation, whose clinical symptoms and EEG responded to a course of combination oral steroids and monthly infusions of intravenous immunoglobulin. He then relapsed after discontinuation of this therapy, and responded again after a second course of intravenous immunoglobulin. We conclude that immunotherapy should be considered as a therapeutic option in patients with LKS who are also found to harbour GRIN2A mutations.
The Rotator Phases of the Normal Alkanes

We present results of an x-ray scattering study on the rotator phases of normal alkanes: CH 2 -(CH 3 )n-CH 2 (20 ≤ ≤ 33). We have characterized a new tilted rotator phase and measured the distortion and tilt order parameters in all 5 rotator phases. We have shown that there is no strong even-odd chain effect within the rotator phases.
Oral P2Y12 Receptor Inhibitors in Hemodialysis Patients Undergoing Percutaneous Coronary Interventions: Current Knowledge and Future Directions

Oral P2Y12 receptor inhibitors are commonly used drugs in patients on hemodialysis (HD) to treat acute coronary syndrome with or without percutaneous coronary intervention (PCI), and patients with stable coronary artery disease after PCI. Clopidogrel is the most commonly prescribed P2Y12 receptor inhibitor because it is effective in the general population and is not as costly as newer FDA-approved agents (prasugrel, ticagrelor). However, increasing evidence is accumulating that clopidogrel may not be as effective in reducing mortality and preventing future ischemic events in patients with kidney disease. In this review, we will explore some of the studies that form the basis for this statement and discuss potential pharmacokinetic and pharmacodynamic reasons why clopidogrel might be less effective in HD patients, as well as explore potential risks and benefits of alternatives to clopidogrel therapy.