cssi/SciSciGPT-SciSciNet huggingface dataset:
Movement of ribosomes over messenger RNA in polysomes of rel + and rel - Escherichia coli strains.

Abstract The in vitro movement of ribosomes over messenger RNA was studied in both the presence and the absence of protein synthesis. For this purpose, labeled polysomes were extracted from rel+ and rel− strains of Escherichia coli grown in the presence of radioactive uracil and incubated in a cell-free system containing tRNA, amino acids, soluble enzymes and a source of energy. The gradual conversion of the labeled polysomes into monosomes and ribosomal subunits was followed by subjecting the reaction mixture to sucrose gradient sedimentation after various incubation times and measuring the radioactivity present in the three relevant ribosomal fractions. It was found that when the conditions of incubation allow protein synthesis to occur, polysomes extracted from rel+ and rel− cells are converted mainly into free monosomes, which can be made to dissociate into subunits by high-sodium or low-magnesium ion concentrations. Under conditions in which protein synthesis cannot occur because a mutant aminoacyl-tRNA synthetase has been rendered inactive, polysome conversion still occurs, though to a reduced extent. When the products of such residual run-off are examined, however, a difference is manifest between polysomes extracted from rel+ and from rel− strains: whereas the polysomes from the rel− strain are still converted into free monosomes even in the absence of protein synthesis, the polysomes from the rel+ strain are now converted mainly into subunits. It can be inferred, therefore, that ribosomes from rel− bacteria, but not those from rel+ bacteria, continue movement over messenger RNA in the absence of protein synthesis. Studies of mixed extracts from rel− and rel+ bacteria have shown that the character of the run-off process does not depend on the source of tRNA and soluble enzymes; the proportions of monosomes and subunits among the run-off products formed in the absence of protein synthesis depend only on the source of the polysomes. It is suggested that the mutation of the rel gene alters the functional architecture of ribosomes.
Elevated platelet microparticles in transient ischemic attacks, lacunar infarcts, and multiinfarct dementias.

Platelets release microparticles (PMP) upon activation. Elevated levels of PMP were observed in patients with immune thrombocytopenic purpura (ITP), sometimes associated with a syndrome resembling transient ischemic attack (TIA), suggesting a thrombogenic potential for PMP. To determine if this association applies to TIA and other cerebrovascular accidents (CVA) without ITP, we studied PMP profiles in 71 patients with ischemic CVA: 28 with small vessel CVA (SCVA), either lacunar infarcts or TIA; 24 with large vessel CVA (LCVA); 19 with multiinfarct dementia (MID); 12 with Alzheimer's dementia (AD); and 31 healthy controls. The mean PMP values were: MID = 3.71 ±0.51; SCVA = 3.48 ±0.63; LCVA = 1.97 ±0.28; AD = 1.19 ±0.27; controls = 0.88 ±0.09, (all units × 107/mL). PMP values in all groups except AD were significantly above normal (p<0.01). However, the elevation in SCVA was more marked than in LCVA (p<0.01). Administration of the calcium channel blocker, nifedipine, to 11 TIA patients reduced PMP significantly.
A vueltas con el legado histórico del Imperio

The last works of H. Kamen and Samuel P. Huntington allows the author to analyze the recent historiography on “imperial studies” in the USA.
Reelin Mobilizes a VAMP7-Dependent Synaptic Vesicle Pool and Selectively Augments Spontaneous Neurotransmission

Summary Reelin is a glycoprotein that is critical for proper layering of neocortex during development as well as dynamic regulation of glutamatergic postsynaptic signaling in mature synapses. Here, we show that Reelin also acts presynaptically, resulting in robust rapid enhancement of spontaneous neurotransmitter release without affecting properties of evoked neurotransmission. This effect of Reelin requires a modest but significant increase in presynaptic Ca 2+ initiated via ApoER2 signaling. The specificity of Reelin action on spontaneous neurotransmitter release is encoded at the level of vesicular SNARE machinery as it requires VAMP7 and SNAP-25 but not synaptobrevin2, VAMP4, or vti1a. These results uncover a presynaptic regulatory pathway that utilizes the heterogeneity of synaptic vesicle-associated SNAREs and selectively augments action potential-independent neurotransmission.
Feasibility of electrical recordings from unconnected vertebrate CNS neurons cultured in a three-dimensional extracellular matrix

Abstract Single, i.e. unconnected spinal or cerebral neurons from chick embryos rapidly regenerate morphologically identifiable axons and dendrites when cultured in a three-dimensional (3-D) extracellular matrix (ECM) consisting of a hydrated native collagen lattice. We now show that it is possible to study the intrinsic electrophysiological properties of such neurons as early as 2 days in culture. Cells were plated at 10 5 cells/dish using Medium 199 containing 10% fetal calf serum but no other supplements or antibiotics-antimycotics. A patch-clamp/whole-cell voltage clamp system was used to record (1) single-channel currents from cell-attached patches, (2) transmembrane potentials during the injection of rectangular currents, and (3) whole-cell currents during voltage clamp. After 2–4 days in culture, isolated cerebral and spinal neurons exhibited single-channel currents. Within 7 days, rectangular currents injected through the recording electrode evoked action potentials. These results demonstrate that unconnected CNS neurons quickly display at least some properties of excitability when cultured in a 3-D ECM. This culture system should facilitate investigation of intrinsic electrical properties of single CNS neurons, and how extrinsic factors including neurotransmitters, hormones, pharmacological agents and contacts with other cells influence electrical activity.
Proposed Uniform Scale for Stiffness of Unbound Pavement Materials for Pavement Design

A review of several relationships commonly used by pavement engineers for structural characterization of subgrade soils, subbase, and base is presented. A careful examination of the literature on the subject revealed that some of the cross‐correlations presented in the 1986 American Association of State Highway and Transportations Officials (AASHTO) thickness design guide (Guide for Design of Pavement Structures) are either invalid or inaccurate. Problems associated with many of these correlations are put in the context of their historical development. A clarification is provided to the current inaccurate cross‐correlation information reported in the 1986 AASHTO guide with regard to the Kentucky version of California bearing ratio (CBR). A common scale for correlating “soil‐strength/ stiffness” parameters, including the resilent modulus, is presented for use with the AASHTO guide as well as mechanistic pavement‐design procedures. A refinement of the AASHTO procedure for selection of resilient modulus of g...
A Romantic Forgery: The Romanesque “Portal” of Saint-Étienne in Toulouse

The portal of the chapterhouse of Saint-Etienne was praised as one of the artistic glories of the Middle Ages when it was first described in 1835 (Fig. 1).1 Alexandre Du Mege published this description in the catalogue of the Musee des Augustins shortly after he had assembled the portal2 out of pieces of sculpture he had salvaged in 1812 from the cloister of the Toulouse cathedral.3 The sculptures had been displayed individually prior to their arrangement as a portal,4 and had been discussed as separate objects in two shorter descriptions of the museum's sculpture collection, which Du Mege had published during these earlier years (Figs. 2–4). The first description had appeared soon after the collection was opened to the public in 1817.5 The second, a slightly revised edition of the previous catalogue, was published in 1828.6 In both publications, Du Mege enumerated fifteen sculptures—eight bas-reliefs, which formed the fabric of the subsequent doorway arrangement, and seven capitals—and said that they had...
Low-Temperature Optical and Resonance Raman Spectra of a Carotenoid Cation Radical in Photosystem II

Low-temperature (77 K) illumination of manganese-depleted Synechocystis PCC 6803 photosystem II core complexes caused the reversible photooxidation of a carotenoid, forming a carotenoid cation radical with an absorbance maximum at 984 nm. Resonance FT-Raman spectra obtained with 1064 nm excitation gave a spectrum characteristic of carotenoid cation radicals in solution. This is the first example of a resonance Raman spectrum of a carotenoid cation radical in a protein. The carotenoid photooxidation requires prior chemical oxidation of cytochrome b559 which implicates the carotenoid in the secondary electron-transfer pathway of photosystem II that may play a role in photoprotection. The possible nature of the pathway and the structure of the carotenoid cation radical are discussed.
Asians as stereotypes and students: Misperceptions that persist

Although Asian Americans today are lauded as a “model minority” and Asian students are praised as “whiz kids,” racial prejudice toward Asians is as true today as it was in the past. American stereotypes of Asians appear characterized by persistent perceptual homogeneity and attitude-behavior inconsistencies. This review aims to: (a) display and analyze the basic stereotype toward Asians, (b) hypothesize an explanation for the basic Asian stereotype, (c) examine the Asian student stereotype by analyzing three factors commonly used to account for the achievement of Asian students, and (d) provide suggestions for research. Arguments for Asians' inherited advantages in IQ and cognitive abilities appear to be questionable. However, the factor of family encouragement and support as well as the work ethic and drive for education factor are found to be advantageous and disadvantageous to achievement, depending on how they are applied. The article discusses homogeneity-heterogeneity of perceptions, attitude-behavior consistency, achievement motivation, parent-child social interaction, mental health, and counseling needs relative to Asian students.
Ring-polymer molecular dynamics: Rate coefficient calculations for energetically symmetric (near thermoneutral) insertion reactions (X + H2) → HX + H(X = C(1D), S(1D))

Following our previous study of prototypical insertion reactions of energetically asymmetric type with the RPMD (Ring-Polymer Molecular Dynamics) method [Y. Li, Y. Suleimanov, and H. Guo, J. Phys. Chem. Lett. 5, 700 (2014)], we extend it to two other prototypical insertion reactions with much less exothermicity (near thermoneutral), namely, X + H2 → HX + H where X = C(1D), S(1D), in order to assess the accuracy of this method for calculating thermal rate coefficients for this class of reactions. For both chemical reactions, RPMD displays remarkable accuracy and agreement with the previous quantum dynamic results that make it encouraging for the future application of the RPMD to other barrier-less, complex-forming reactions involving polyatomic reactants with any exothermicity.
In vitro bone strain distributions in a sample of primate pelves.

The pelvis is a critical link in the hindlimb locomotor system and has a central role in resisting loads associated with locomotion, but our understanding of its structural biomechanics is quite limited. Empirical data on how the pelvis responds to the loads it encounters are important for understanding pelvic adaptation to locomotion, and for testing hypotheses regarding how the pelvis is adapted to its mechanical demands. This paper presents in vitro strain gauge data on a sample of monkey and ape cadaveric specimens (Macaca, Papio, Ateles, Hylobates), and assesses strain magnitudes and distributions through the bones of the pelvis: the ilium, ischium and pubis. Pelves were individually mounted in a materials testing system, loads were applied across three hindlimb angular positions, and strains were recorded from 18 locations on the pelvic girdle. Peak principal strains range from 2000 to 3000 μe, similar to peak strains recorded from other mammals in vivo. Although previous work has suggested that the bones of the pelvis may act as bent beams, this study suggests that there are likely additional loading regimes superimposed on bending. Specifically, these data suggest that the ilium is loaded in axial compression and torsion, the ischium in torsion, the pubic rami in mediolateral bending, and the pubic symphysis is loaded in a combination of compression and torsion. Compressive strains dominate the pelves of all species representatives. Shear strains change with limb position; hip flexion at 45 ° induces smaller shear strains than mid-stance (90 °) or hip extension (105 °). The pelvic girdle is a complex structure that does not lend itself easily to modeling, but finite element analyses may prove useful to generate and refine hypotheses of pelvic biomechanics.
Temperature dependence of morphology and magnetic properties of cobalt nanoparticles prepared by an inverse micelle technique

We have fabricated cobalt nanoparticles using sodium borohydride reduction of cobalt chloride in a didodecyldimethylammonium bromide (DDAB)/toluene inverse micelle solution. The particle morphology changed from single particles to clusters as we increased the reaction temperature. Intracluster dipole−dipole interaction increased the blocking temperature and reduced the effective magnetic moment per cluster.
Measurement of the X-ray emission of the solar atmosphere during a period of low activity

A large-area high-sensitivity X-ray spectrometer has been constructed and used to measure the 1.8–5.3 A X-ray emission of the Sun under quiescent conditions. The instrument utilizes Bragg reflection from mosaic graphite crystals. The data indicate that the X-ray emission can best be accounted for by a multitemperature model of the solar atmosphere in which both the over-all corona and active regions contribute to the X-ray spectrum. Theoretical calculations of the X-ray flux of a hot, optically thin plasma have been used to estimate the solar conditions at the time when the measurements were made.
Distribution of adriamycin in cancer patients. Tissue uptakes, plasma concentration after IV and hepatic IA administration

Twenty patients with solid tumors received 30 mg/M2 of adriamycin. Various tissue samples were intraoperatively obtained from 18 patients, about 1.5--5 hours after an intravenous (IV) bolus dose. Normal liver showed the highest levels of adriamycin uptake (2.3--19.8 micrograms/g); lymph nodes were second; muscle and bone marrow, next; fat and skin had the lowest adriamycin uptake (0.04--0.40 microgram/g). Tumor tissue, excluding that with much necrosis and hemorrhaging, had adriamycin concentrations which approximated those of the liver (1.1--9.2 micrograms/g). Six patients, all with hepatic malignancies, had prolonged plasma concentration studies after IV administration; 5 also had adriamycin administered directly into the hepatic artery catheter. Adriamycin-plasma-time courses were similar, whether the drug was administered by bolus directly into the hepatic artery or peripheral vein. The concentration of metabolites after hepatic intraarterial administration was definitely higher than that after IV administration. Patients with hepatic dysfunction had delayed plasma clearance and secondarily elevated levels approximately 160 and 300 minutes after administration.
A Radiation-Hardened CMOS 8-Bit Analog-to-Digital Converter

The increasing use of LSI circuits in advanced systems has required the incorporation of linear (analog) functions into digital Bulk CMOS LSI devices. This design required a radiation-hardened 8-bit successive approximation analog-to-digital converter (ADC) which would be implemented as a macrocell of a 24-channel data acquisition system on a single LSI circuit. The ADC and two operational amplifiers were first fabricated on a small chip for characterization testing. These parts were packaged and the characterization tests were successful, indicating better than 8-bit accuracy. Of these parts, six were irradiated at 2 × 106 rads (Si) per hour, each with different bias conditions. All but one of the parts were functional after 5 × 105 rads (Si) total dose and all but two were still accurate to 7-bit accuracy after 1 × 106 rads (Si). The one unit which failed was a gross linearity failure; the test results plus the bias conditions indicate that the offset cancellation switch became leaky, causing the failure. This portion of the circuit has been redesigned to eliminate the problem, and future tests are pending.
Application of the fuzzy control strategy to adaptive force control of non-minimum phase end milling operations

Abstract A new on-line force control scheme is developed in machining operations by using the fuzzy set theory. Based on this new control strategy, very complex and uncertain processes can be controlled more easily and accurately compared to standard approaches for improving productivity. Furthermore, the computational task and time can be reduced as compared to classical or modern control theory. In this research, schematic control rules are constructed by using real experimental data produced by the pole placement adaptive control algorithm. Afterwards, experimental work, based on the end milling operation was carried out to verify that the fuzzy control scheme is applicable to the force control.
New methodology for development of regional vehicle-mapping tables for MOBILE emissions model

Among the many input factors to the MOBILE emissions model, vehicle miles traveled (VMT) fractions (the percentage of VMT for different types of vehicles by roadway functional classes) plays an important role because different types of vehicles produce emissions at different rates. In addition, since the vehicle classification scheme of MOBILE is different from the FHWA vehicle types used in traffic data collection, a vehicle-mapping table that converts VMT fractions from FHWA types to MOBILE types deserves special attention. The research described in this paper produced a new methodology to develop a vehicle-mapping table by using readily available data sources, namely, (a) vehicle registration data from the Department of Motor Vehicles of Virginia and (b) Vehicle Inventory and Use Survey data from the Bureau of the Census. To evaluate the new methodology, a vehicle-mapping table for Virginia was developed and then compared with three commonly used mapping-table methodologies. In addition, on the basis o...
Transient thermal analysis of lnGaN/GaN laser diodes

We have investigated the transient thermal behavior and heat distribution in a multi-quantum wells (MQWs) InGaN/GaN lasers diode for λ∼445 nm based on GaN substrate. 2D thermal modeling was performed to estimate the dissipation of heat from the active region. Different thermal designs for planner and solder ball bumps packages have been studied using Al 2 O 3 , ceramic-AlN and SiC as submount materials. Comparative study of the planner to that of the solder ball bumps using thermal interfacial materials of Au metallization, AuSn solder, diamond heat spreader and Al block as heat sink. We found that planner package design using SiC as submount can be a material of choice. Furthermore, LIV characteristics show as much as 2 fold enhancement in the output power of the optimized design when operated at elevated injected current ∼1000 mA.
CORRELATIONS BETWEEN RADIOLOGIC HEART SIZE AND ORTHOGONAL ELECTROCARDIOGRAMS IN PATIENTS WITH LEFT VENTRICULAR OVERLOAD.

Abstract Correlations between radiologic heart size and electrocardiographic measurements of the QRS complex were performed in 100 patients with clinical evidence of left ventricular overload (LVO). Frank's corrected orthogonal lead system was used. ECG analysis was performed by digital computation. Radiologic heart size correlated best with: (1) spatial magnitude of the time integral of QRS (SÂQRS); (2) the sum of R wave magnitudes in leads X and Z; (3) rightward displacement of point J; (4) time interval between the onset of QRS and the peak of the R wave in lead X. Combinations of either one of the first two criteria with the third or fourth were found to be best for the recognition of cardiac enlargement in patients with left ventricular overload. When the number of false-positive cases was reduced to zero, the maximal recognition rate, based solely on QRS criteria, was 76 per cent. A narrow and/or figure-of-eight QRS loop configuration in the horizontal plane projection was found frequently in cases with cardiac enlargement. This finding may serve as a clue for predicting left ventricular enlargement.
The Hydrogen Permeability of Sulfur Resistant Palladium-Copper Alloys at Elevated Temperatures and Pressures

Pd-Cu alloys are being considered for hydrogen membrane applications because of their resistance to sulfur poisoning. Therefore the permeance of Pd-Cu alloys containing 53, 60, and 80 wtPd has been determined over the 623 – 1173 K temperature range for H2 partial pressure drops as great as 2.75 MPa. The results indicate that Pd-Cu alloy composition and thermal history influence membrane permeance. The 60%Pd-40%Cu alloy exhibited very high permeance at 623 K, although both the 53%Pd and 60Pd alloys exhibited a distinct drop in permeability at higher temperatures due to the transition of the Pd-Cu crystal structure from bcc to fcc. Upon cooling the membrane back to 623 K, the permeability of the 60%Pd alloy was initially an order-of-magnitude less than its initial value, but the permeance increased steadily with time as the Pd – Cu crystal structure slowly reverted to bcc. The fcc 80%Pd alloy was less permeable than the bcc 60Pd alloy at 623 K, but the 80Pd alloy was more permeable than the fcc 60%Pd alloy at elevated temperatures.
New Biological Insights on the Link Between Radiation Exposure and Breast Cancer Risk

Radiation exposure is a well-documented risk factor for breast cancer in women. Compelling epidemiological evidence in different exposed populations around the world demonstrate that excess breast cancer increases with radiation doses above 10 cGy. Both frequency and type of breast cancer are affected by prior radiation exposure. Many epidemiological studies suggest that radiation risk is inversely related to age at exposure; exposure during puberty poses the greatest risk while exposures past the menopause appear to carry very low risk. These observations are supported by experimental studies in mice and rats, which together provide the basis for the pubertal ‘window of susceptibility’ hypothesis for carcinogenic exposure. One line of experimental investigation suggests that the pubertal epithelium is more sensitive because DNA damage responses are less efficient, an other suggests that radiation affects stem cells self-renewal. A recent line of investigation suggests that the irradiated microenvironment mediates cancer risk. Studying the biological basis for radiation effects provides potential routes for protection in vulnerable populations, which include survivors of childhood cancers, as well as insights into the biology for certain types of sporadic cancer.
Effects of speaker variability and noise on Mandarin tone identification by native and non-native listeners

The purpose of this study was to examine whether speaker variability and noise affect native and non-native listeners differently in Mandarin tone perception. Multi-speaker tone stimuli embedded in speech-shaped noise were presented blocked by speaker or mixed across speakers. The listeners included 20 native listeners and 33 non-native listeners with various degree of Mandarin proficiency, defined by years of Mandarin instruction and baseline performance. The results showed that the mixed-speaker presentation did not affect non-native listeners disproportionately, suggesting that speaker variability did not pose a special challenge to non-native listeners. In contrast, noise disrupted native and non-native perception differently, but it was the listeners with higher Mandarin proficiency that were affected disproportionately. These findings suggest that that not all sources of acoustic variability are equally disruptive to native and non-native speech perception.
Cocaine induces apoptosis in cerebral vascular muscle cells: potential roles in strokes and brain damage.

Abstract Cocaine abuse is known to induce different types of brain-microvascular damage and many adverse cerebrovascular effects, including cerebral vasculitis, intracranial hemorrhage, cerebral infarction and stroke. A major physiological event leading to these pathophysiological actions of cocaine could be apoptosis. Whether cocaine can cause brain-microvascular pathology and vascular toxicity by inducing apoptosis of cerebral vascular smooth muscle cells is not known. This study, using several different methods to discern apoptosis, was designed to investigate if primary cultured canine cerebral vascular smooth muscle cells can undergo apoptosis when treated with cocaine. After treatment with cocaine (10 −6 –10 −3 M) for 12–24 h, the death rates of cerebral vascular smooth muscle cells increased in a concentration-dependent manner compared with controls. Morphological analysis of cerebral vascular smooth muscle cells using confocal fluoresence microscopy showed that the percentage of apoptotic cerebral vascular smooth muscle cells increased after cocaine (10 −6 –10 −3 M) treatment in a concentration-dependent manner. TUNEL assays also showed positive results for cerebral vascular smooth muscle cells treated with cocaine. These results clearly demonstrate that cerebral vascular smooth muscle cells can undergo rapid apoptosis in response to cocaine in a concentration-dependent manner. Cocaine-induced apoptosis may thus play a major role in brain-microvascular damage, cerebral vascular toxicity and strokes.
Lithium, a preliminary survey of its mineral occurrence in flint clay and related rock types in the United States

Abstract Maximum concentrations of lithium found in samples of flint clay and associated rocks of Pennsylvanian age in different States, in parts per million (ppm), are: Missouri, 5100; Pennsylvania-Maryland, 2100; Kentucky, 890; Ohio, 660; Alabama, 750; and Illinois, 160. Lithium-bearing kaolin deposits are distributed in the Coastal Plain province from New Jersey to Texas, and one occurs in Idaho; maximum lithium concentrations in samples from these deposits range from 64 to 180 ppm. The maximum concentration found in the Arkansas bauxite region is 460 ppm and that in flint clay in Colorado is 370 ppm. Samples from areas other than Pennsylvania, Maryland, Kentucky and Missouri are relatively few in number, represent mostly commercially valuable clays, and represent only a part of the refractory clay deposits in the United States. Data are not available on the clays associated with these deposits that may be unusable because they contain too much lithium as well as other deleterious elements. In both Pennsylvania and Missouri, lithium contents vary regionally between districts and locally between deposits. In samples containing more than 2000 ppm lithium, the lithium occurs in a dioctahedral chlorite mineral very similar to cookeite, which previously has not been recognized in sedimentary clays. The associated clays consist chiefly of well-crystallized kaolinite. The dioctahedral chlorite, however, seems to be most abundant where diaspore and boehmite occur along with the kaolinite. Barium, chromium, copper, phosphorus and strontium are present in some samples in amounts of several hundred pans per million or more, and may contribute to the failure of some clays to perform satisfactorily in firing tests. Lithium-rich clays could serve as a significant lithium resource in the very distant future. Clays that contain as much as 1% lithium may be common enough in Missouri or in Pennsylvania to be produced as a by-product to help support benefication costs for refractory clays. Sufficient amounts of lithium-rich clay may be found in deposits that have been explored, found unsatisfactory for normal refractory uses, and not developed. The lithium-rich clay in some deposits presently being worked may be worth stockpiling for eventual use.
Differential Cross Section for Charged A 1 Photoproduction Using the Regge Exchange Formalism

The Regge-pole formalism is applied to the calculation of the differential cross section for ${{A}_{1}}^{+}$ photo-production in the region $|{t}_{min}|l\ensuremath{-}tl10{\ensuremath{\mu}}^{2}$. The $\ensuremath{\rho}$, ${A}_{1}$, ${A}_{1}$-daughter, ${A}_{2}$, and $\ensuremath{\pi}$ trajectory contributions are considered, and use is made of chiral dynamics to estimate the unknown coupling constants. We find that the $\ensuremath{\pi}$ and the ${A}_{2}$ trajectories provide the dominant contributions.
Prediction of Mechanical Behavior of Balloon-Expandable Stents

Coronary heart disease is a major health threat for people in the developed countries. Narrowing of the coronary arteries is one of the most common types of coronary heart diseases and is often treated by percutaneous transluminal coronary angioplasty (PTCA) and recently by stenting. A stenting procedure involves inserting a slotted metal tube or coil into the artery and expanding it to help achieve a sufficient luminal size. To optimize the design of stents, we have developed a finite element model of the stenting procedure. The results showed the distal ends of the stent could damage arteries due to non-uniform expansion of the stent. Our model also showed that inclusion of the plaque and artery is important for predicting the final stent shape and diameter. A response surface of the stent hoop stiffness is proposed to help designers quickly decide the stiffness of the stent for a given design. Results show that contact stresses are inversely proportional to stent stiffness and a minimum stent hoop stiffness is needed to prevent stent collapse after balloon removal.Copyright © 2004 by ASME
Why we still use our heads instead of formulas: toward an integrative approach.

This review begins with a discussion of Meehl's (1957) query regarding when to use one's head (i.e., intuition) instead of the formula (i.e., statistical or mechanical procedure) for clinical prediction. It then describes the controversy that ensued and analyzes the complexity and contemporary relevance of the question itself. Going beyond clinical inference, it identifies select cognitive biases and constraints that cause decision errors, and proposes remedial correctives. Given that the evidence shows cognition to be flawed, the article discusses the linear regression, Bayesian, signal detection, and computer approaches as possible decision aids. Their cost-benefit trade-offs, when used either alone or as complements to one another, are examined and evaluated. The critique concludes with a note of cautious optimism regarding the formula's future role as a decision aid and offers several interim solutions.
Correlation of trunk muscle strength with age in children 5 to 18 years old.

Objective To determine the correlation of trunk muscle strength with age in children and the effect of gender on changes in trunk muscle strength. Material and Methods Strength of the back extensors and back flexors was evaluated in 137 healthy boys and 109 healthy girls who were 5 to 18 years old. Anthropometrie determinations of height and weight were done in all study subjects. Maximal back muscle strength was measured with an isometric dynamometer (BID-2000). Standardized positioning techniques were used to allow comparison with the follow-up evaluations. Results Regression analysis revealed significant increases in trunk strength with increasing age; the strength of the boys began diverging from that of the girls at age 9 to 10 years. Back extensor strength also increased with increasing height and weight, and expected differences were noted between boys and girls. Strength levels ranged from 80 to 774 newtons (18 to 174 lb). Mean back extensor strength in 2-year age intervals ranged from 153 newtons (34.4 lb) in girls 5 to 7 years old to 504 newtons (113.3 lb) in boys 16 to 18 years of age. (Each newton is equal to 0.2248 lb.) Conclusion Results of this study demonstrated that age, height, and weight are all important predictors of trunk strength in children, and the effects of these factors are modulated by gender.
Improved Vascular Gene Transfer With a Helper-Dependent Adenoviral Vector

Background— Adenoviral vectors are the most widely used agents for vascular gene transfer. However, the utility of adenoviral vectors for vascular gene transfer is limited by brevity of expression and by the induction of a significant host inflammatory response. Third-generation or “helper-dependent” adenoviral vectors have achieved prolonged recombinant gene expression in liver and muscle with minimal associated inflammation; however, they have never been tested for vascular gene transfer. Methods and Results— We constructed a helper-dependent adenoviral vector expressing rabbit urokinase plasminogen activator (HD-AduPA). HD-AduPA was compared, in a rabbit model of carotid gene transfer, with a first-generation adenovirus, also expressing rabbit uPA (FG-AduPA). uPA expression and vector DNA were measured in arteries harvested from 3 to 56 days after gene transfer. Vector-specific mRNA, vascular inflammation, and neointimal formation were assessed 14 days after gene transfer. uPA expression was lost, and ...
Photocurrent spectroscopy of a strained-layer superlattice

Abstract Strained-layer superlattices (SLS's) are a new kind of semiconductor material, grown from lattice-mismatched constituents, whose electronic properties may be tailored over a wide range. We report the growth by metal-organic chemical vapor deposition of a GaAs 0.4 P 0.6 /GaP SLS, and the characterization of its room temperature electronic properties by photocurrent spectroscopy. The results are consistent with predictions of an effective-mass (Kronig-Penney) model.
Redox-responsive dynamic-covalent assemblies: stars and miktoarm stars

Dynamic-covalent macromolecular stars were prepared by cross-linking block copolymers containing reactive maleic anhydride units with a disulfide-containing diamine. Here we report the synthesis of disulfide-cross-linked star polymers obtained by the arm-first process. Well-defined block copolymers containing a reactive poly(styrene-alt-maleic anhydride) (P(S-alt-MAn)) segment and an inert polystyrene or poly(N-isopropylacrylamide) segment were obtained by reversible addition–fragmentation chain transfer (RAFT) polymerization. Facile ring-opening of the pendant anhydride groups in the block copolymers by a disulfide-linked diamine cross-linker led to core-cross-linked stars with redox-responsive cores. The reductive cleavage of the disulfide linkages in the cross-linked cores resulted in star dissociation into linear arms with pendant thiol groups. Oxidation of the pendant thiol units of the resulting unimers in the presence of air led to reassembly or self-healing of the stars without the need for an ext...
Clonal growth of primary cultures of human hyaline chondrocytes in a defined medium.

Rapid clonal growth of primary cultures of human costal chondrocytes in a defined medium has been achieved. The basal nutrient medium used for such growth is MCDB 104. It is prepared without linoleic acid and supplemented with 1 μg/ml insulin, 100 ng/ml fibroblast growth factor, 1.0 × 10−7 M dexamethasone, and 5 μg/ml mixed lipids, presented to the cells in the form of liposomes. The lipid supplement contains soybean lecithin, cholesterol, sphingomyelin, vitamin E, and vitamin E acetate. No expression of cartilage-like differentiation occurs in the defined medium. However, colonies grown for several days in the defined medium and then grown for an additional period of time in medium F12 supplemented with fetal bovine serum and chicken embryo extract synthesize large amounts of refractile matrix that is stained intensely by acidified alcian green, thus demonstrating that the cells growing in the defined medium are capable of expressing cartilage matrix in a permissive environment. Good clonal growth and expression of differentiation can also be obtained by inoculating primary cultures of human chondrocytes directly into the F12-serum-embryo extract medium.
Proof of the hepatic synthesis of a sex-dependent protein in the rat.

Abstract An α 2 -globulin ( α 2u ), previously purified from the urine of male rats, has been identified immunologically in the liver, kidneys and serum. This protein was associated with the microsomal fraction of the liver but not that of the kidneys. Total nephrectomy yielded in 6 h a 30-fold accumulation of α 2u above the normal plasma concentration of 3 mg per 100 ml. Simultaneous partial hepatectomy or administration of puromycin inhibited its accumulation. The perfusion of rat liver in vitro with blood containing [ 14 C]glycine led to the production of radioactively labeled α 2u . These studies demonstrate the hepatic synthesis of the sex-related α 2 -globulin originally isolated from male rat urine.
Suppression of the inducible form of nitric oxide synthase prior to traumatic brain injury improves cytochrome c oxidase activity and normalizes cellular energy levels.

Abstract We have previously shown that the observed immediate increase in nitric oxide (NO) plays a significant role in the control of the cerebral microcirculation following traumatic brain injury (TBI). However, a second consequence of increased NO production after TBI may be impaired mitochondrial function, due to the fact that NO is a well-known inhibitor of cytochrome c oxidase (CcO). CcO is a key enzyme of the mitochondrial oxidative phosphorylation (OxPhos) machinery, which creates cellular energy in the form of ATP. NO competes with oxygen at the heme a 3 –Cu B reaction center of CcO. We thus hypothesized that TBI triggers inhibition of CcO, which would in turn lead to a decreased energy production by OxPhos at a time of an elevated energy demand for tissue remodeling. Here we show that TBI as induced by an acceleration weight drop model of diffuse brain injury in rats leads to CcO inhibition and dramatically decreased ATP levels in brain cortex. CcO inhibition can be partially restored by application of iNOS antisense oligonucleotides prior to TBI, which leads to a normalization of ATP levels similar to the controls. We propose that a lack of energy after TBI caused by inhibition of CcO is an important aspect of trauma pathology.
In vitro vs in vivo chromatographic profiles of carbaryl anionic metabolites in man and lower animals.

Abstract An in vitro technique for metabolic studies utilizing liver tissue has been developed based upon successful organ maintenance methods and chromatographic profiles. This technique qualitatively reflects in vivo metabolic processes of animals, including man, under prescribed conditions without resorting to the risk of dosing human beings. This was accomplished by the utilization of the published literature on in vivo metabolism of carbaryl in rat, dog, guinea pig and man. Under the required conditions, which simulate a dose level comparable to a chronic no-ill-effect feeding level in the rat, the variations between these in vitro and the previous in vivo results are substantially less than between species.
Progressive approximate aggregate queries with a multi-resolution tree structure

Answering aggregate queries like SUM, COUNT, MIN, MAX, AVG in an approximate manner is often desirable when the exact answer is not needed or too costly to compute. We present an algorithm for answering such queries in multi-dimensional databases, using selective traversal of a Multi-Resolution Aggregate (MRA) tree structure storing point data. Our approach provides 100% intervals of confidence on the value of the aggregate and works iteratively, coming up with improving quality answers, until some error requirement is satisfied or time constraint as reached. Using the same technique we can also answer aggregate queries exactly and our experiments indicate that even for exact answering the proposed data structure and algorithm are very fast.
Spinal muscarinic receptors are activated during low or high frequency TENS-induced antihyperalgesia in rats

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological modality used clinically to relieve pain. Central involvement of serotonin and endogenous opioids are implicated in TENS-induced analgesia. Activation of spinal cholinergic receptors is antinociceptive and these receptors interact with opioid and serotonin receptors. In the current study, the possible involvement of spinal cholinergic receptors in TENS analgesia was investigated in rats. Hyperalgesia was induced by inflaming one knee joint with 3% kaolin-carrageenan and assessed by measuring paw withdrawal latency (PWL) to heat before and 4 h after injection. The non-selective nicotinic antagonist mecamylamine (50 microg), non-selective muscarinic antagonist atropine (30 microg) or one of the muscarinic subtype antagonists: pirenzepine (M1, 10 microg), methoctramine (M2, 10 microg), 4-DAMP (M3, 10 microg), or saline was administered intrathecally just prior to TENS treatment. Low or high frequency TENS was then applied to the inflamed knee and PWL was determined again. Atropine, pirenzepine and 4-DAMP significantly attenuated the antihyperalgesic effects of low and high frequency TENS while mecamylamine and methoctramine had no effects, compared to saline control. The results show that TENS-induced antihyperalgesia is mediated partially by activation of spinal muscarinic receptors but not spinal nicotinic receptors. Further, the results also indicate that spinal M1 and M3 muscarinic receptor subtypes mediate the muscarinic component of TENS antihyperalgesia.
Rule utilitarianism, rights, obligations and the theory of rational behavior

The paper first summarizes the author’s decision-theoretical model of moral behavior, in order to compare the moral implications of the act-utilitarian and of the rule-utilitarian versions of utilitarian theory. This model is then applied to three voting examples. It is argued that the moral behavior of act-utilitarian individuals will have the nature of a noncooperative game, played in the extensive mode, and involving action-byaction maximization of social utility by each player. In contrast, the moral behavior of rule-utilitarian individuals will have the nature of a cooperative game, played in the normal mode, and involving a firm commitment by each player to a specific moral strategy (viz. to the strategy selected by the rule-utilitarian choice criterion) — even if some individual actions prescribed by this strategy, when considered in isolation, should fail to maximize social utility.
A Physics-Based Terrain Model for Off-Road Vehicle Simulations

We present the development of a three-dimensional Vehicle/Tire/Terrain Interaction Model (VTTIM) consisting of a general 3D tire-terrain traction model which operates on a novel deformable terrain representation that utilizes a soil compaction model. Rather than utilizing popular empirical terramechanics models that only consider the pressure/sinkage directly under the tire, the governing equations of the terrain are based on i) the propagation of subsoil stresses due to vehicular loads, and ii) the resulting stress/strain which is based on a visco-elastic-plastic soil model developed by Ayers and Bozdech. The implementation of the terrain model is modularized in the form of an API, as the vehicle and tire are assumed to be contained in commercial simulation software as to focus on the implementation of the deformable terrain model. A number of test simulations are run using a rigid tire with and without grousers to show the capability of the VTTIM to predict tire forces for use in vehicle mobility and traction performance simulations. Power and energy required to deform the terrain will also be presented with the simulation results, which allows the prediction of the extra power required by a vehicle traveling on off-road, deformable soil.Copyright © 2012 by ASME
A model of a radially expanding and contracting lymphangion

The lymphatic system is an extensive vascular network featuring valves and contractile walls that pump interstitial fluid and plasma proteins back to the main circulation. Immune function also relies on the lymphatic system's ability to transport white blood cells. Failure to drain and pump this excess fluid results in edema characterized by fluid retention and swelling of limbs. It is, therefore, important to understand the mechanisms of fluid transport and pumping of lymphatic vessels. Unfortunately, there are very few studies in this area, most of which assume Poiseuille flow conditions. In vivo observations reveal that these vessels contract strongly, with diameter changes of the order of magnitude of the diameter itself over a cycle that lasts typically 2-3s. The radial velocity of the contracting vessel is on the order of the axial fluid velocity, suggesting that modeling flow in these vessels with a Poiseuille model is inappropriate. In this paper, we describe a model of a radially expanding and contracting lymphatic vessel and investigate the validity of assuming Poiseuille flow to estimate wall shear stress, which is presumably important for lymphatic endothelial cell mechanotransduction. Three different wall motions, periodic sinusoidal, skewed sinusoidal and physiologic wall motions, were investigated with steady and unsteady parabolic inlet velocities. Despite high radial velocities resulting from the wall motion, wall shear stress values were within 4% of quasi-static Poiseuille values. Therefore, Poiseuille flow is valid for the estimation of wall shear stress for the majority of the lymphangion contractile cycle.
Multiphysics coupling of dynamic fluid flow and electromagnetic fields for subsurface sensing

Summary form only given. Electromagnetic (EM) measurement has been extensively applied in subsurface sensing while fluid flow modeling is capable of characterizing subsurface fluid flow behavior. The multiphysics coupling of the EM measurement and dynamic fluid flow analysis has significant potential to improve electromagnetic geophysical exploration with injecting electromagnetic contrast agents.
Transcatheter embolisation of patent ductus arteriosus using an Amplatzer vascular plug in six dogs.

Objectives: The objective of this study was to assess the feasibility of transcatheter embolisation of a patent ductus arteriosus using an Amplatzer vascular plug (Amplatzer Medical UK) in six dogs. Methods: The Amplatzer vascular plug is a self-expandable, cylindrical device attached to a delivery cable. In all the dogs, the device was delivered transvenously. Successful device implantation was defined as firm anchorage of the device squarely within the distal part of the ductus arteriosus with no intra- or postoperative dislodgement. Successful occlusion of the ductus arteriosus occurred if a disappearance of the continuous murmur was achieved 24 hours after placement of the Amplatzer vascular plug. Results: The age of the dogs ranged from 16 weeks to 7·5 years. Their weights ranged from 2·9 to 27·6 kg (median 6 kg). Two dogs had congestive heart failure before embolisation. Successful device implantation was achieved in all dogs. Successful occlusion of the ductus arteriosus was achieved in four of the six dogs. Complications included mild lameness, residual shunting, and bruising and pruritus around the surgical wound site. At follow-up, two dogs had a continuous murmur and one required treatment for congestive heart failure. Clinical Significance: This technique may represent a clinically effective and less expensive alternative to the use of an Amplatzer duct occluder (Amplatzer Medical UK) in dogs with medium-sized patent ductus arteriosus. Further investigations are required to fully evaluate its efficacy and safety in various sizes and types of patent ductus arteriosus, and to determine the optimal device size in relation to the size of the ductus.