cssi/SciSciGPT-SciSciNet huggingface dataset:
Mass spectrometry studies of fission product behavior: I. Fission products released from irradiated LWR fuel

Abstract Quadrupole mass spectrometry has been used to study the chemical form and rate of release of volatile fission products (e.g., Xe, Kr, Cs, Te, and I) effusing from irradiated LWR fuel samples. In experiments up to a temperature of 2120 K, krypton, xenon, cesium, and tellurium were identified as the species released from the fuel. A weak signal was observed for atomic iodine at 1325 K. The source of the atomic iodine (e.g., it could be either dissociation of cesium iodide or dissociation of molecular iodine) has yet to be resolved. A most significant finding was lack of observation of molecular cesium iodide. The observed rate of release of xenon was several orders of magnitude lower than previously reported. The xenon release rate, however, increased significantly after the fuel was oxidized. In complementary experiments on nonradioactive simulated fuel, it was found that the release of tellurium was hindered by dissolution in Zircaloy cladding. Above 1300 K, gaseous SnTe was observed; its formation was attributed to reaction of the tellurium with tin in the cladding.
Chapter 1 From millisecond to attosecond laser pulses

Publisher Summary This chapter presents an overview intended for nonspecialists who wish to become acquainted with the remarkable developments in time-resolved optical techniques. The evolution from the nanosecond to the femtosecond regime is outlined, based on familiar nonlinear optical processes, including saturable absorption, intensity-dependent index of refraction, and self-focusing and self-phase modulation. A true revolution in femtosecond generation occurred when it was discovered that a titanium–aluminum oxide (Ti-sapphire) laser crystal would yield very short pulses without the use of a saturable absorber. Self-focusing of the laser beam in the Ti-sapphire crystal occurs due to its intensity-dependent index of refraction. In combination with a suitably placed aperture, the self-focusing can cause a larger fraction of the pulse energy to pass through the aperture at higher intensity. Thus, less absorption and more gain occur for more intense parts of the stochastic amplified spontaneous emission. This so-called Kerr-lens self-focusing is a purely dispersive effect. The transition to the attosecond regime is described. It requires extreme nonlinear processes, including tunneling and the creation of quasi-free electrons, which enable a transition from the visible to the X-ray spectral region. Attosecond technology may be used for investigations of collision physics with Auger processes in atoms with inner-shell vacancies and for molecular collision processes.
Multicenter phase II study of iodine-131 tositumomab for chemotherapy- relapsed/refractory low-grade and transformed low-grade B-cell non-Hodgkin's lymphomas

PURPOSE: This multicenter phase II study evaluated the efficacy, dosimetry methodology, and safety of iodine-131 tositumomab in patients with chemotherapy-relapsed/refractory low-grade or transformed low-grade non-Hodgkin’s lymphoma (NHL). PATIENTS AND METHODS: Patients received a dosimetric dose that consisted of 450 mg of anti-B1 antibody followed by 35 mg (5 mCi) of iodine-131 tositumomab. Serial total-body gamma counts were then obtained to calculate the patient-specific millicurie activity required to deliver the therapeutic dose. A therapeutic dose of 75 cGy total-body dose (attenuated to 65 cGy in patients with platelet counts of 101,000 to 149,000 cells/mm3) was given 7 to 14 days after the dosimetric dose. RESULTS: Forty-five of 47 patients were treated with a single dosimetric and therapeutic dose. Twenty-seven patients (57%) had a response. The response rate was similar in patients with low-grade (57%) or transformed low-grade (60%) NHL. The median duration of response was 9.9 months. Fifteen p...
Lack of limb or sex differences in the cutaneous vascular responses to exogenous norepinephrine

The cutaneous circulation is used to examine vascular adrenergic function in clinical populations; however, limited studies have examined whether there are regional limb and sex differences in micr...
Quantifying Water Density Fluctuations and Compressibility of Hydration Shells of Hydrophobic Solutes and Proteins

We probe the effects of solute length scale, attractions, and hydrostatic pressure on hydrophobic hydration shells using extensive molecular simulations. The hydration shell compressibility and water fluctuations both display a nonmonotonic dependence on solute size, with a minimum near molecular solutes and enhanced fluctuations for larger ones. These results and calculations on proteins suggest that the hydration shells of unfolded proteins are more compressible than of folded ones contributing to pressure denaturation. More importantly, the nonmonotonicity implies a solute curvature-dependent pressure sensitivity for interactions between hydrophobic solutes.
Respiratory symptoms and lung function abnormalities among machine operators in automobile production

This cross-sectional study was designed to assess differences in prevalence of respiratory symptoms and lung function between machine operators exposed to semisynthetic or soluble metal-working fluids (MWFs) and unexposed assemblers and to assess exposure-response relationships with MWF type, total aerosol, endotoxin, culturable bacteria and fungi. We evaluated 183 machine operators and 66 assemblers from one large automobile transmission plant using questionnaires, spirometry data, and cross-shift assessment of both lung function and respiratory symptoms. We found that airborne exposures to total aerosol, endotoxin, culturable bacteria and fungi were higher in machine operations than in the assembly area. There was a correlation between bulk and airborne culturable bacteria, but not between bulk and airborne culturable fungi. Machine operators had significantly more usual cough, usual phlegm, work-related chest tightness and post-shift symptoms of chest tightness, throat irritation, and cough compared with assemblers. We found exposure-response relationships between respiratory symptoms and total aerosol, as well as culturable fungi and bacteria. Associations with endotoxin were not strong or consistent, possibly because airborne levels were generally low. Cross-shift lung function decrements did not differ between machine operators and assemblers and there were no associations with MWF or specific exposures. The finding of respiratory symptoms at low levels of exposure in this study suggests the need to re-assess total aerosol thresholds. Associations between airborne fungal exposures and respiratory symptoms need further study to characterize sources of exposure other than MWF in machining operations. Am. J. Ind. Med. 31:403–413, 1997. © 1997 Wiley-Liss, Inc.
Brain Glutamate Metabolism: Neuronal-Astroglial Relationships

The concentration of glutamate in the brain extracellular fluid must be kept low (∼3 µ M )in order to maximize the signal-to-noise ratio upon the release of glutamate from neurons. In
OBSERVATION OF AN ANOMALY IN THE THERMAL RESISTIVITY AND THE LORENTZ NUMBER OF THE METALLIC ANTIFERROMAGNET CeAl.

A 20% peak in the thermal resistivity $w$ is observed in the temperature interval 7 to 12\ifmmode^\circ\else\textdegree\fi{}K for CeAl, an antiferromagnet with a N\'eel temperature of 9.5\ifmmode^\circ\else\textdegree\fi{}K. The maximum value of $w$ occurs above ${T}_{\mathrm{N}}$ at about 9.8\ifmmode^\circ\else\textdegree\fi{}K, while the slope $\frac{\mathrm{dw}}{\mathrm{dT}}$ has a positive peak at ${T}_{\mathrm{N}}$. This is the first experimental evidence for a divergent $\frac{\mathrm{dw}}{\mathrm{dT}}$ in a metallic magnet. The Lorentz number has a monotonic temperature dependence with $\frac{\mathrm{dL}}{\mathrm{dT}}$ maximum at ${T}_{\mathrm{N}}$.
Sonolytic desorption of mercury from aluminum oxide: effects of pH, chloride, and organic matter.

The effects of pH, Cl-, and humic acid (HA) on sonolytic desorption of Hg(II) from aluminum oxide were examined. Results showed that Hg(II) desorption was achieved by lowering the pH from 7.0 to 4.0. Ultrasound enhanced Hg(II) release at short times compared to both hydrodynamic mixing and that expected on the basis of the pH-dependent Hg(II) adsorption curve. However, prolonged sonication led to decreases in Hg(II) desorption due to occlusion by aluminum hydroxide precipitation induced by ultrasound. The presence of Cl- greatly improved Hg(II) desorption at pH 4.0 due to the formation of stable nonadsorbing HgCl20 complexes at low pH, reducing free Hg(II) ion in solution. However, Cl- did not affect Hg(II) desorption at pH 8.0, where Hg(OH)20 is the dominant Hg species rather than HgCl20. Hg(II) desorption from HA-laden Al2O3 was dominated by HA. The greater the desorption of HA, the greater the desorption of Hg(II). Ultrasound enhanced the initial Hg(II) release by facilitating HA desorption. However, d...
Coherent Optical Spatial Filtering of Diatoms in Water Pollution Monitoring

The use of Fourier transform coherent optical techniques in the pattern recognition of microscopic algae, i.e., diatoms, is described. The results of the construction of complex-valued filters for diatoms and their usefulness in algal identification are presented. Some general applications to water pollution monitoring and control are discussed.
How Does Tie Strength Affect Access to Social Capital Resources for the Careers of Working and Middle Class African-Americans?:

This study uses qualitative interviews with 50 working and middle class African-Americans to explore how they use social capital resources from their strong and weak ties to obtain education and jo...
Bulk-alloy microstructural analogues for transient liquid-phase bonds in the NiAl/Cu/Ni system

Transient liquid-phase (TLP) bonds between dissimilar materials can have complex microstructures that evolve both during holding at the bonding temperature and on cooling. In this article, an examination is made of the feasibility of producing bulk-alloy microstructural analogues for individual microstructural features of dissimilar material TLP bonds. The ultimate intent of this work is to enable the contribution of individual microstructural features to the overall properties of TLP bonds to be determined. Specifically, the article focuses on the production, characterization, and applications of microstructural analogues for TLP bonds in an NiAl/Cu/Ni model system. The article examines the use of five different cast Ni-Al-Cu alloys, together with heat treatment of selected materials, as bulk analogues for six distinct microstructural regions of the NiAl/Cu/Ni bonds. Each of these analogues is characterized in detail by transmission electron microscopy (TEM) and compared to the relevant target region of the bond. An initial examination is also made of the use of bulk alloys in aiding an understanding of phase transformations and structure-property relationships in these bonds.
Habituation of optically evoked blink reflex in mentally retarded adults

This study was done to record the difference in habituation patterns of optically evoked blink reflexes in mentally retarded and normal adults. Sets of photic stimuli with fixed interstimulus duration were utilized in normal volunteers and mentally retarded adults. The interstimulus duration decreased with each sequential set. The blink responses were recorded on fibreoptic recording paper. These electrophysiological methods show objectively that the blink responses to light which habituate in normal adults fail to do so in those who are mentally retarded.
Blood transfusions after thoracoscopic anterior thoracolumbar vertebrectomy

Purpose Anterior vertebral body reconstruction (AVBR) for trauma or tumor involves corpectomy and placement of hardware to reconstitute the anterior weight-bearing stability of the spine. We report our clinical experience with thoracoscopic techniques for AVBR.
Coverage Strategies in Wireless Sensor Networks

An energy efficient cover of a region using Wireless Sensor Networks (WSNs) is addressed in this paper. Sensor nodes in a WSN are characterized by limited power and computational capabilities, and are expected to function for extended periods of time with minimal human intervention. The life span of such networks depends on the efficient use of the available power for sensing and communication. In this paper, the coverage problem in a three dimensional space is rigorously analyzed and the minimum number of sensor nodes and their placement for complete coverage is determined. Also, given a random distribution of sensor nodes, the problem of selecting a minimum subset of sensor nodes for complete coverage is addressed. A computationally efficient algorithm is developed and implemented in a distributed fashion. Numerical simulations show that the optimized sensor network has better energy efficiency compared to the standard random deployment of sensor nodes. It is demonstrated that the optimized WSN continues to offer better coverage of the region even when the sensor nodes start to fail over time. A localized “self healing” algorithm is implemented that wakes up the inactive neighbors of a failing sensor node. Using the “flooding algorithm” for querying the network, it is shown that the optimized WSN with integrated self healing far outweighs the performance that is obtained by standard random deployment. For the first time, a “measure of optimality” is defined that will enable the comparison of different implementations of a WSN from an energy efficiency stand point.
Percutaneous reconstruction of isolated bile ducts: Combination of percutaneous and endoscopic biliary techniques

Reconstruction of isolated biliary segments can be achieved using a combination of radiologic and endoscopic interventions.
Intravenous, non-viral RNAi gene therapy of brain cancer.

RNA interference (RNAi) has the potential to knock down oncogenes in cancer, including brain cancer. However, the therapeutic potential of RNAi will not be realised until the rate-limiting step of delivery is solved. The development of RNA-based therapeutics is not practical, due to the instability of RNA in vivo. However, plasmid DNA can be engineered to express short hairpin RNA (shRNA), similar to endogenous microRNAs. Intravenous, non-viral RNAi-based gene therapy is enabled with a new gene-targeting technology, which encapsulates the plasmid DNA inside receptor-specific pegylated immunoliposomes (PILs). The feasibility of this RNAi approach was evaluated by showing it was possible to achieve a 90% knockdown of brain tumour-specific gene expression with a single intravenous injection in adult rats or mice with intracranial brain cancer. The survival of mice with intracranial human brain cancer was extended by nearly 90% with weekly intravenous injections of PILs carrying plasmid DNA expressing a shRNA...
Diagnosis and management of infectious thyroiditis.

A broad range of disorders can cause inflammation of the thyroid gland. True thyroid infections are rare and can result from a variety of microorganisms, of which bacteria are the most common. Other rarer pathogens include fungi, parasites, and viruses. Gram-positive bacteria, especially staphylococci, predominate as causative agents in adults and children. In immunocompromised patients, opportunistic pathogens have been isolated. Most infections in adults occur as a result of hematogenous or lymphatic seeding of the thyroid gland. In children, congenital anomalies can lead to thyroid infection and require surgical correction to prevent recurrence. Fine-needle aspiration of the thyroid is usually required to identify the infecting agent, and prolonged antimicrobial therapy with or without surgical drainage is the cornerstone of management. This review outlines the pathogenesis, microbiology, diagnosis, and management of infectious thyroiditis in adults and children and compares this disorder with other, more common causes of thyroid inflammation.
Effect of beta-adrenergic blockade on plasma lactate concentration during exercise at high altitude.

When unacclimatized lowlanders exercise at high altitude, blood lactate concentration rises higher than at sea level, but lactate accumulation is attenuated after acclimatization. These responses could result from the effects of acute and chronic hypoxia on β-adrenergic stimulation. In this investigation, the effects of β-adrenergic blockade on blood lactate and other metabolites were studied in lowland residents during 30 min of steady-state exercise at sea level and on days 3, 8, and 20 of residence at 4300 m. Starting 3 days before ascent and through day 15 at high altitude, six men received propranolol (80 mg three times daily) and six received placebo. Plasma lactate accumulation was reduced in propranolol- but not placebo-treated subjects during exercise on day 3 at high altitude compared to sea-level exercise of the same percentage maximal oxygen uptake (\(\dot VO_{2max}\)). Plasma lactate accumulation exercise on day 20 at high altitude was reduced in both placebo- and propranolol-treated subjects compared to exercise of the same percentage \(\dot VO_{2max}\)performed at sea level. The blunted lactate accumulation during exercise on day 20 at high altitude was associated with reduced muscle glycogen utilization. Thus, increased plasma lactate accumulation in unacclimatized low-landers exercising at high altitude appears to be due to increased β-adrenergic stimulation. However, acclimatization-induced changes in muscle glycogen utilization and plasma lactate accumulation are not adaptations to chronically increased β-adrenergic activity.
Passive polarization-enhanced/encoded visible imagery for invariant target recognition

In previous work we showed that polarization-enhancement/encoding imagery can effectively be used to improve the detection and discrimination of targets. In this paper, we present a design and analysis of a new synthetic discriminant function for rotation/scale invariant for this polarization imagery system. Performance comparison between the proposed SDF and SDF obtained in traditional methods is included.
The structure of a silicon analog of the psychotropic drug perathiepin: 5,5-dimethyl-10-(4-methylpiperazinyl)-10,11-dihydro-5H-dibenzo[b,f]silepin hydrofumarate

Abstract The solid state structure of the hydrofumarate salt of 5,5-dimethyl-10-(4-methylpiperazinyl)-1O,11-dihydro-5 H -dibenzo[ b , f ]silepin (II), a silicon analog of perathiepin (I) in which divalent sulfur is replaced by the (CH 3 ) 2 Si moiety, has been determined by X-ray diffraction methods. The compound, C 25 H 32 N 2 O 4 Si, crystallizes in the orthorhombic space group, Pbc 2 1 with a 9.304(2), b 23.010(7), c 11.599(3) A; the structure was refined by full-matrix least-squares techniques to a conventional R of 0.039 for 1858 counter reflections. The structure consists of a network of hydrogen-bonded hydrofumarate anions and the protonated heterocyclic unit. The tricyclic framework of the cation adopts a folded boat conformation with a dihedral angle between benzo group planes of 151.2°. In contrast to related systems, the piperazinyl substituent which has the expected chair conformation occupies a pseudoaxial site on the ethano bridge. Structural parameters of the tricyclic framework of the title compound and related compounds are compared.
Epoprostenol treatment for idiopathic pulmonary arterial hypertension in pregnancy

Idiopathic pulmonary arterial hypertension is a rare condition associated with significant maternal mortality. We report the management of a 37-year-old multigravida with severe disease using epoprostenol, a multidisciplinary approach, and a planned delivery. Although the patient survived the pregnancy, her pulmonary function significantly worsened. Epoprostenol, a pulmonary vasodilator, should be considered when indicated during pregnancy. Neither fetal nor neonatal harm was identified.
SEX DIFFERENCES IN MEMORY ESTIMATES, REVISITED

207 undergraduate students (95 men and 112 women) representing all four years in college provided estimates of memory performance before and after a recall task involving 80 stimuli (40 pictures and 40 words). The study was intended as a replication of the work of Ionescu in 2000 wherein men underestimated their performance on the picture items and women underestimated their performance on the words. No sex differences were found for correct recall totals, recall for pictures, recall for words, and total prerecall performance estimates. Although both men and women underestimated their pre- and postrecall performance, women underestimated their postrecall performance more than men. More importantly, men underestimated their performance on recall of pictures, whereas women underestimated their performance on the word items, thereby validating prior results with a larger sample. The possible bases for this phenomenon are still not clear.
Turn-On Fluorescence Detection of Cyanide in Water: Activation of Latent Fluorophores through Remote Hydrogen Bonds That Mimic Peptide β-Turn Motif

A molecular probe was prepared that selectively responds to cyanide in aqueous solutions by fluorescence enhancement. Using the peptide β-turn as a structural template, we designed a series of diphenylacetylene derivatives in which the π-conjugated backbone was functionalized with an aldehyde group to render the molecule nonfluorescent. The N−H···O hydrogen bond across the 2,2′-functionalized diphenylacetylene turn motif activates the carbonyl group toward nucleophilic attack, and chemical transformation of this internal quencher site by reaction with CN− elicits a rapid (k = 72 M−1 s−1) enhancement in the emission at λmax = 375 nm. Tethering of an ammonium group to the hydrogen bond donor fragment significantly increased both the response kinetics and the intensity of the fluorescence signal. In addition to providing electrostatic attraction toward the CN− ion, this positively charged R-NH3+ fragment can engage in a secondary hydrogen bond to facilitate the formation of the cyanohydrin adduct responsible...
Cleavage of Amyloid-β Precursor Protein and Amyloid-β Precursor-like Protein by BACE 1

Site-specific proteolysis of the amyloid-beta precursor protein (APP) by BACE 1 and gamma-secretase, a central event in Alzheimer disease, releases a large secreted extracellular fragment (called APP(S)), peptides of 40-43 residues derived from extracellular and transmembrane sequences (Abeta), and a short intracellular fragment (APP intracellular domain) that may function as a transcriptional activator in a complex with the adaptor protein Fe65 and the nuclear protein Tip60. APP is closely related to APP-like protein (APLP) 1 and APLP2, but only APP is known to be cleaved by BACE 1 and to be involved in Alzheimer disease. We now demonstrate that similar to APP, APLP1 and APLP2 are also cleaved by BACE 1 but not by ADAM 9, another APP protease, and also transactivate nuclear Tip60 in a complex with Fe65. Paradoxically, although BACE 1 cleavage appears to be specific for APP and APLPs, their cleavage sequences exhibit no homology, and a short sequence (7 amino acids) from APP that when placed close to the membrane converts a membrane protein that is normally not cleaved by BACE 1 into a BACE 1 substrate. Our data demonstrate that APLPs and APP are processed similarly to act via the same nuclear target, suggesting that BACE 1 cleavage regulates a common function of APP and APLPs in neurons.
Evolution of the Dynamics and Thermodynamics of a Mesoscale Convective System: A Case Study

Abstract A well-organized severe storm complex on 30 May 1976 developed in the southeastern part of the mesonetwork of the National Severe Storms Laboratory (NSSL) in central Oklahoma and merged, in its mature stage, with a band of thunderstorms along a stationary front. Rawinsonde observations at nine stations within the mesonetwork, supplemented by satellite time lapse images, have been analyzed to depict the kinematic and thermodynamic structure of the storm and its near environment. An objective analysis technique is used to describe the evolving storm structure. Among the significant features the analysis revealed, the low-level horizontal convergence was confined to the southeast prior to the appearance of the first cloud in the satellite images, and a well-defined mixed layer, capped by a strong stable layer, developed with northwest to southeast horizontal temperature and moisture, gradients. The height of the mixed layer increased with time in the dry northwest side, while it decreased in the sou...
Crisis and conservation at the end of the world: sheep ranching in Argentine Patagonia

Patagonia was one of the last regions in the Americas to be settled by Europeans. It was not until the mid-1880s that the Argentine government secured effective control over the region, after which settlement and economic development were based on sheep ranching. Virtually free of domesticated animals in 1885, by 1910 Patagonian rangelands supported some 12 million sheep. This growth was sustained until 1952, when the sheep population of the region peaked at approximately 22 million, but the number of sheep in Patagonia has since declined to about 13 million. Numerous factors have been implicated in the collapse of sheep ranching, one of great significance being the very poor state of Patagonian rangelands. Soil erosion is widespread, and the flora has been so heavily modified that it is extremely difficult, if not impossible, to determine what the composition and characteristics of Patagonia's pre-European vegetation were. This paper reviews the evolution of Patagonia's sheep industry and the nature and extent of environmental degradation caused by livestock. Although researchers have long called for a response to the environmental and socio-economic dimensions of the crisis, only in the past decade have initiatives to assess, monitor, and reverse degradation in Patagonia been launched. These initiatives often promote the diversification of land-use and alternative production strategies. Case study evidence from the upper Percey River watershed in western Chubut province indicates that ranchers may view alternative livelihoods with suspicion. It is suggested that measures to restore and protect Patagonian ecosystems would gain greater acceptance if local producers were seen as equals in the conservation and development process. This could be achieved by replacing more-traditional top-down models of policy design and implementation with measures based on genuine consultation and participatory, community-based approaches to natural resource management.
Measles at Disneyland, a Problem for All Ages

Although great progress has been made in global control, measles has recently rebounded in many countries. Eradication is possible but will take time, ramped-up efforts to ensure that eligible U.S....
Ternary Logic Network Justification Using Transfer Matrices

A linear algebraic method is developed that allows for logic network justification problems to be solved. The method differs from previous techniques that require learning or solution space search techniques in that all possible justification solutions are determined through a single vector-matrix product calculation. The logic network is represented by a matrix that is defined as the "justification" matrix. It is shown that the justification matrix is simply the transpose of the network transfer matrix and is thus easily obtained through a traversal of the network netlist. Example justification calculations are provided.
Radiation oncology: Postgraduate medical education in the United States, 1988

The fourteenth survey of postgraduate medical education in radiation oncology in the United States was conducted in the first three months of 1988. It revealed stability in the number of approved programs, positions offered, and physicians in training compared with 1986. The proportion of trainees who were U.S. citizens by birth rose to an all-time high of 88%, and the proportion of foreign medical graduates decreased to 9%. The proportion of women in residency has remained unchanged (24%) over the past 6 years. At present, approximately 150 physicians complete residency and enter practice each year, one-third of whom commence in an academic setting. A high proportion of recent graduates of approved programs successfully completes the examinations and becomes certified by the American Board of Radiology.
Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding Computational Analyses

Johnson-Cook strength material model is frequently used in finite-element analyses of various manufacturing processes involving plastic deformation of metallic materials. The main attraction to this model arises from its mathematical simplicity and its ability to capture the first-order metal-working effects (e.g., those associated with the influence of plastic deformation, rate of deformation, and the attendant temperature). However, this model displays serious shortcomings when used in the engineering analyses of various hot-working processes (i.e., those utilizing temperatures higher than the material recrystallization temperature). These shortcomings are related to the fact that microstructural changes involving: (i) irreversible decrease in the dislocation density due to the operation of annealing/recrystallization processes; (ii) increase in grain-size due to high-temperature exposure; and (iii) dynamic-recrystallization-induced grain refinement are not accounted for by the model. In this study, an attempt is made to combine the basic physical-metallurgy principles with the associated kinetics relations to properly modify the Johnson-Cook material model, so that the model can be used in the analyses of metal hot-working and joining processes. The model is next used to help establish relationships between process parameters, material microstructure and properties in friction stir welding welds of AA5083 (a non-age-hardenable, solid-solution strengthened, strain-hardened/stabilized Al-Mg-Mn alloy).
From switched-capacitors to digital filters

Abstract Digital filters have been realized with inexpensive reverse switched capacitors and expensive special purpose digital computers. Analysis shows that the semi-null inherent in any switched capacitor can be eliminated with an analog-to-digital converter realization which is intermediate in cost. The main emphasis is on band-pass filter realization by means of the overlapping spectra method and a preferred ordering of the cascaded filter sections. Band-rejection filter realization is considered for completeness.
Development of Drifting Buoy Systems for Oceanographic and Meteorological Applications

During the last decade, the launch of a series of polar-orbiting satellites to be used for climatological studies, and also capable of surface platform position location and data telemetry, prompted the development of relatively low-cost oceanographic and meteorological drifting buoy measurement platforms to support a wide spectrum of scientific and observational programs. The feasibility of economically and reliably deploying meteorological drifting buoys in remote data-sparse areas of the world has been amply demonstrated in the recent Global Weather Experiment. Drifting buoy technology will play an increasingly important role in climate-related research programs during the next decade. The role of drifting buoy data in improving weather analysis and forecasts may be a dominant factor in the development of operational drifting buoy systems. Development programs are underway or in planning to upgrade the measurement capabilities of the present drifting buoy systems in response to anticipated future demands.
Recurrence of amblyopia after occlusion therapy.

Purpose To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. Design Retrospective, population-based, consecutive observational case series. Participants Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. Methods We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)–level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as ≥2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. Main Outcome Measure Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. Results Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. Conclusions There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age ( P
Thalassinoides-Phycodes compound burrow systems in Paleocene deep-water limestone, Southern Alps of Italy

Abstract Compound burrow systems, consisting of branching, horizontal tunnels in the core areas of the systems intergrading with fan-like tunnels in distal areas, are common in the Paleocene Scaglia Cinerea limestone. If preserved as isolated elements, the cores would be identified as Thalassinoides suevicus and the distal elements as Phycodes cf. palmatus. These complex trace fossils are probably combination dwelling-deposit feeding structures produced by endobenthic crustaceans that occupied and ‘operated’ the systems for relatively long intervals of time. Compounds such as these may be more common than supposed and represent an important, but essentially unexploited, source of biologic information on marine invertebrate trace producers.
INFLUENCE OF ACTIVATED FLY ASH ON CORROSION-RESISTANCE AND STRENGTH OF CONCRETE

Abstract Various activation techniques, such as physical, thermal and chemical were adopted. By adopting these methods of activation, hydration of fly ash blended cement was accelerated and thereby improved the corrosion-resistance and strength of concrete. Concrete specimens prepared with 10%, 20%, 30% and 40% of activated fly ash replacement levels were evaluated for their compressive strengths at 7, 14, 28 and 90 days and the results were compared with ordinary Portland cement concrete (without fly ash). Corrosion-resistance of fly ash cement concrete was studied by using anodic polarization technique. Electrical resistivity and ultrasonic pulse velocity measurements were also carried out to understand the quality of concrete. The final evaluation was done by qualitative and quantitative estimation of corrosion for different systems. All the studies confirmed that upto a critical level of 20–30% replacement; activated fly ash cement improved both the corrosion-resistance and strength of concrete. Chemical activation of fly ash yielded better results than the other methods of activation investigated in this study.
Eating Maps: Places, Times, and People in Eating Episodes

This project developed a method for constructing eating maps that portray places, times, and people in an individual's eating episodes. Researchers used seven consecutive days of qualitative eating recall interviews from 42 purposively sampled U.S. adults to draw a composite eating map of eating sites, meals, and partners for each person on a template showing home, work, automobile, other homes, and other places. Participants evaluated their own maps and provided feedback. The eating maps revealed diverse places, times, and partners. Eating maps offer a flexible tool for eliciting, displaying, validating, and applying information to visualize eating patterns within contexts.
Characterization of semiconductor device structures by modulation spectroscopy

This paper reviews the use of modulation spectroscopy for the characterization of a wide variety of semiconductor device structures. Some systems that will be discussed include pseudomorphic GaAlAs/InGaAs/GaAs modulation-doped quantum-well high-electron-mobility transistors (including the 300K determination of the 2D electron gas density), GaAlAs/GaAs, InP/InGaAs, InGaP/GaAs, InAlAs/InGaAs, and InGaAs/GaAs heterojunction bipolar transistors (including the determination of the built-in fields/doping levels in the emitter and collector regions), GaAs/GaAlAs quantum well IR detectors, quantum well lasers, etc. Particular attention will be paid to nondestructive, contactless techniques such as photoreflectance and contactless electroreflectance that can be performed on entire wafers.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Growth factors and wound healing.

Abstract Growth factors are peprides that stimulate cell growth and proliferation. They have typically been named after their target cell (eg, epidermal growth factor, or EGF), their source (eg, platelet-derived growth factor, or PDGF), or biologic property (eg, transforming growth factor, or TGF). These peptides have both paracrine and autocrine functions, affecting neighboring cells and permitting self-regulation, respectively. The actions of growth factors are typically mediated by cellular receptors. Binding of growth factors and kinase receptors initiates autophosphorylation of the receptor and intracellular proteins, which then act as second messengers to initiate nuclear transcription (eg, EGF, PDGF, and insulin-like growth factor or IGF). 1,2 Nuclear transcription factors activate or enhance gene transcription, and cellular proliferation then ensues. 2 Growth factors have been linked to oncogenes, which are genes of viral or cellular origin whose expression transforms a cell toward the malignant phenotype. Oncogenes may encode for growth factors, their receptors, phosphorylating enzymes, or other key elements in ligand transmission. 1,2
Starch xanthate–polyethylenimine reaction mechanisms

The chemical nature of starch xanthate (SX)–polyethylenimine (PEI) reaction products has been studied because of their effectiveness as wet-end additives for improving strength properties of paper. Model compounds, in conjunction with ultraviolet, infrared, and chemical analyses, served to elucidate SX–PEI reaction mechanisms. Aqueous solutions of SX (degrees of substitution 0.1–0.5) were titrated with PEI at pH 5–7 (25–30°C) to form SX–PEI flocculent precipitates that were determined to be polyelectrolyte complexes. However, when solutions of SX–PEI were kept at pH 10–12, products were formed that included dithiocarbamic acid salts in major quantities, PEI thioureas, and minor quantities of O-starch PEI thinocarbamate. Acid precipitation of these SX–PEI polymeric reaction products from their alkaline solutions, which contained residual xanthate and PEI, also yielded polyelectrolyte complexes. Model systems suggest that PEI thiuram disulfide and starch xanthide, possible products of air oxidation, could be present in minor amounts and would react rapidly with PEI to yield thioureas and thioncarbamates, respectively. Apparently, mixtures of xanthate and amine gave (1) dithiocarbamic acid salts from both xanthate groups and CS2 (decomposition from xanthate), (2) thioureas from both dithiocarbamic acid salts and thiuram disulfide, and (3) thioncarbamates, principally from xanthate as opposed to xanthide.
Elastic anomalies in superlattices: an explanation

Abstract An explanation for the elastic anomalies that have been previously reported in metallic superlattices is presented. The explanation, valid for superlattices with sharp interfaces, makes use of the charge transfer which occurs when two metals with different work functions are in contact. However, contrary to the case of bulk materials where the transferred charge remains localized at the surface, in thin layers the transferred charge is distributed throughout the layer. This change in charge distribution explains the observed anomalies in the lattice constants and in the elastic properties.
Climate and prehistory on the Yucatan peninsula

Long held notions that climate has been stable over the Yucatan peninsula and that today's climate is an accurate reflection of past climates here are being challenged today by a number of researchers. Both empirical and circumstantial evidence are offered for a prolonged and severe period of dessication in the Maya lowlands and its effects on soils, vegetation, lake levels and ancient Maya cultural processes, ca. 50 B.C. to 500 A.D. After centuries of steady and precocious growth and development, Late Preclassic Maya civilization in the drier northern two thirds of the peninsula abruptly collapsed, probably due to repeated crop failures and decreasing availabilities of potable water due to severe drought conditions. This is nowhere more apparent than at the predominantly Preclassic ruins of El Mirador - the largest known ancient Maya city - which was almost totally abandoned by A.D. 250. Thereafter, the development of classicism was confined to a small and better watered area in extreme northeastern Guatemala, northern Belize and southern Quintana Roo, which was defended from invaders from the north by a line of fortified sites.
Graphene has ultra high piezoresistive gauge factor

We report the first-ever use of graphene as a piezoresistive element in a MEMS device, and report on a giant piezoresistivity in the graphene films used on our devices. Owing to the layer nature and the effective confinement of electrons in two-dimensions, applied strain in the graphene films is likely to create large changes in conductivity as the electrons are forces to traverse larger potential wells along increased bond-lengths or result in modulation of current along grain boundaries and multiple graphene layers. In this paper we report a very high piezoresistive gauge factor of 1.8×104. This gauge factor is orders of magnitude higher than that of most piezoresistive materials used in MEMS. This high value of piezoresistivity could be transformative in reinterpretation of the use of piezoresistivity for various hybrid transduction approaches.
A Functional Anatomic Defect of the Cystic Fibrosis Airway

Rationale: The mechanisms underlying cystic fibrosis (CF) lung disease pathogenesis are unknown. Objectives: To establish mechanisms linking anion transport with the functional microanatomy, we evaluated normal and CF piglet trachea as well as adult swine trachea in the presence of selective anion inhibitors. Methods: We investigated airway functional microanatomy using microoptical coherence tomography, a new imaging modality that concurrently quantifies multiple functional parameters of airway epithelium in a colocalized fashion. Measurements and Main Results: Tracheal explants from wild-type swine demonstrated a direct link between periciliary liquid (PCL) hydration and mucociliary transport (MCT) rates, a relationship frequently invoked but never experimentally confirmed. However, in CF airways this relationship was completely disrupted, with greater PCL depths associated with slowest transport rates. This disrupted relationship was recapitulated by selectively inhibiting bicarbonate transport in vitro and ex vivo. CF mucus exhibited increased viscosity in situ due to the absence of bicarbonate transport, explaining defective MCT that occurs even in the presence of adequate PCL hydration. Conclusions: An inherent defect in CF airway surface liquid contributes to delayed MCT beyond that caused by airway dehydration alone and identifies a fundamental mechanism underlying the pathogenesis of CF lung disease in the absence of antecedent infection or inflammation.
Sharecropping and the plantation economy in the United States South

(1983). Sharecropping and the plantation economy in the United States South. The Journal of Peasant Studies: Vol. 10, Sharecropping and Sharecroppers, pp. 120-129.
Our pledge to achieve safety.

It has become glaringly apparent that delivering safe radiation therapy is more complex and associated with more risk than was previously understood. The public exegesis of several treatment transgressions has identified both the spectacular natureof andtheunfortunate aspectsofradiation therapy failures (1). Therecognitionofthesefailureshasbeenatransformative event for the field of industrial and systems engineering in radiation oncology. Engineering and manufacturing processes have become the new language for clinical operations and patient care. Much is discussed about the departmental safety culture in which resetting the traditional norms defines and influences operational behaviors. As a result, we would expect that radiation oncology facilities in the United States have had fresh discussions about safety and have very likely reinforced rules, policies, or processes hoping to mitigate risk. But has this resulted in safer radiation therapy? We are still learning about risk mitigation and how best to implement processes without being disruptive to the needed efficiency of a busy clinical practice. Information from event-reporting databases, discussions at national meetings, failure modes and effects analysis, and root cause analysis studies are yielding important information that will establish and advance operational performance for radiation oncology. Nonetheless, we remain in the no man’s land between our aspirations for evidence-based improvements and public expectations for patient safety vs. actual performance outcomes. Our department has reconstructed every aspect of care from the initial consultation to the initiation, continuation, and completion of therapy and developed a quality checklist approach to verify that all aspects of care are addressed and completed (2, 3). We have implemented interlocks (the ‘‘no-fly’’ policy) for treatment initiation when certain items are incomplete and perform root cause analysis rounds weekly for each noncompliant event. We have spent the last 18 months using our multicenter clinic to quantify and process the operations of radiation oncology, in an effort to distill the essence of what is necessary to mitigate risk while maintaining efficient and forwardlooking operations. We decided that the six-sigma approach toward processdriven operations such as radiation therapy provides the most robust tool to improve quality and safety performance. Implementation of this process included education and detailed instructions, along with several safety-first initiatives. The department’s paperless environment allows us to calculate our compliance and efficiency using a monthly Z-score. Yet, several months after the kickoff of this process, wewere disappointed that our Z-scores barely changed. These results appear to indicate that policies and procedures to improve quality may be ineffective for that purpose.