cssi/SciSciGPT-SciSciNet huggingface dataset:
Subsurface mobility of metribuzin as affected by crop residue placement and tillage method

The role of crop residues as a sorptive layer for herbicides applied in conservation tillage systems is not well understood. The organic mulch may retain herbicides and decrease chemical mobility and off-site transport. Field and laboratory experiments were conducted to determine the effects of surface placement of crop residues on herbicide mobility in Norge silt loam (fine-silty, mixed, mesic Udic Paleustoll). In the field, four treatments were established that included no-till plots with all crop residues removed (NTRR), residues left standing (NTRS), residues cut and laid flat on ground (NTRF), and plots that were moldboard plowed to incorporate residues (MT). An application of 1.15 kg ha -1 of metribuzin [4-amino+(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazine-5(4H)-one] and 50 kg ha -1 of potassium bromide was made. Soil cores were taken to 1-m depth following an initial sprinkler irrigation and natural rainfalls. Wheat residues intercepted metribuzin and attenuated subsurface movement in NT soils. Standing crop residues or residues placed flat on the soil surface resulted in more metribuzin in the near-surface zone ; centers of mass of concentration distributions in NTRS and NTRF soils showed that metribuzin moved only 47 to 62% of the distance observed in MT soil after 45 and 175 mm of precipitation, respectively. Addition of straw matter to soil and elevated organic C concentrations in the near-surface zone of no-till soils resulted in two- to fivefold increase in metribuzin retention. Therefore, placement geometry of crop residues and the retention capacity of the near-surface zone could be managed to attenuate metribuzin mobility in the field to achieve optimal herbicidal functions and dissipation.
Acoustic anomalies in terbium molybdate near the improper ferroelastic-ferroelectric phase transition

The anomaly in the longitudinal elastic constant ${\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{C}}_{11}$ of terbium molybdate (TMO) associated with the ferroelastic-ferroelectric phase transition at 160\ifmmode^\circ\else\textdegree\fi{}C was investigated by Brillouin scattering spectroscopy. An analysis is presented, based on the phenomenological theory of Levanyuk, which describes both the thermodynamic anomaly due to induced bilinear coupling in the low-symmetry phase and the effects of anharmonic coupling of strain to critical fluctuations of the order parameter which occurs in both phases. Soft-mode dispersion curves from neutron scattering experiments and the temperature-dependent magnitude of the order parameter deduced from x-ray and birefringence studies were used as input for the data-fitting procedures. In our analysis of the data in the low-temperature ferroelectric phase, we consider four models for the second ${A}_{1}$ soft mode which is the partner of the 5.7-meV mode. With the assumption that the coupling constant ${K}_{2}$ between an acoustic phonon and a pair of soft optic phonons is independent of the soft-mode wave vector, only the fourth model produced a self-consistent fit to our data over the range $20\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}l~Tl~400\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ which is also consistent with previous studies of the soft mode.
Statistical simulation of complete events in energetic nuclear collisions

Abstract A statistical model is developed for the generation of complete multifragment events in medium-energy nuclear collisions. Based on simple geometrical considerations, the collision system is divided into a few (participant/spectator) sources that disassemble independently. The sufficiently excited sources quickly explode into pions, nucleons, and composite, possibly particle unstable, nuclei. The different final states compete according to their microcanonical weight. The less excited sources, and the unstable explosion products, deexcite by sequential light-particle emission. The model has been implemented as a Monte Carlo computer code that is sufficiently efficient to permit generation of large event samples. The analysis of such multifragment events is addressed and some illustrative applications are discussed.
Nanoscale adhesion, friction and wear studies of biomolecules on silicon based surfaces

Protein layers are deployed over the surfaces of microdevices such as biological microelectromechanical systems (bioMEMS) and bioimplants as functional layers that confer specific molecular recognition or binding properties or to facilitate biocompatibility with biological tissue. When a microdevice comes in contact with any exterior environment, like tissues and/or fluids with a variable pH, the biomolecules on its surface may get abraded. Silicon based bioMEMS are an important class of devices. Adhesion, friction and wear properties of biomolecules (e.g., proteins) on silicon based surfaces are therefore important. Adhesion was studied between streptavidin and a thermally grown silica substrate in a phosphate buffered saline (PBS) solution with various pH values as a function of the concentration of biomolecules in the solution. Friction and wear properties of streptavidin (protein) biomolecules coated on silica by direct physical adsorption and a chemical linker method were studied in PBS using the tapping mode atomic force microscopy at a range of free amplitude voltages. Fluorescence microscopy was used to study the detailed wear mechanism of the biomolecules. Based on this study, adhesion, friction and wear mechanisms of biomolecules on silicon based surfaces are discussed.
Self-similar wavepackets for describing warm dense matter

Using the time dependent variational principle, we develop a general formulation of single particle quantum dynamics within the assumption that the wavepacket's density remains self-similar. We obtain the amplitude-phase relationship from the continuity equation. We investigate the ground state properties of waves with Gaussian and exponential densities in hydrogenic and helium-like systems. We show that the exponential wavepackets yield superior ground state energies - an important advantage in describing warm dense matter (T < 50 eV) in which bound states form. Exponentials yield an improved ground state energy for molecular hydrogen, but with a bond length 13% short of the experimental value.
Decreasing Birth Weight May Predispose Premature Infants to Increased Mortality From Necrotizing Enterocolitis

The objective of this study was to determine if there are any “risk factors” that could assist clinicians in identifying premature infants who are at greater risk for mortality when developing necr...
Succession may maintain high leaf area : Sapwood ratios and productivity in old subalpine forests

Old forests are generally believed to exhibit low net primary productivity (NPP) and therefore to be insignificant carbon sinks. This relationship between age and NPP is based, in part, on the hypothesis that the biomass of respiratory tissues such as sapwood increases with age to a point where all photosynthate is required just to maintain existing tissue. However, this theoretical connection between respiration:assimilation ratios and forest productivity is based on age-dependent trends in the sapwood:leaf ratios of individual trees and even-aged stands; it does not take into account such processes in natural forests as disproportional increases in shade-tolerant species over time and multiple-age cohorts. Ignoring succession and structural complexity may lead to large underestimates of the productivity of old forests and inaccurate estimates of the ages at which forest productivity declines. To address this problem, we compared biomass allocation and productivity between whitebark pine, a shade-intolerant, early-successional tree species, and subalpine fir, a shade-tolerant, late-successional species, by harvesting 14 whitebark pines and nine subalpine firs that varied widely in dbh and calculating regression models for dbh vs annual productivity and biomass allocation to leaves, sapwood, and heartwood. Late-successional subalpine fir allocated almost twice as much biomass to leaves as early-successional whitebark pine. Subalpine firs also had a much lower allocation to sapwood and higher growth rates across all tree sizes. We then modeled biomass allocation and productivity for 12 natural stands in western Montana that were dominated by subalpine fir and whitebark pine varying in age from 67 to 458 years by applying the regressions to all trees in each stand. Whole-stand sapwood:leaf ratios and stand productivity increased asymptotically with age. Sapwood:leaf ratios and productivity of whitebark pine in these stands increased for approximately 200–300 years and then decreased slowly over the next 200 years. In contrast, sapwood:leaf ratios of all sizes of subalpine fir were lower than those of pine and productivity was higher. As stands shifted in dominance from pine to fir with age, subalpine fir appeared to maintain gradually increasing rates of whole-forest productivity until stands were approximately 400 years old. These results suggest that forests such as these may continue to sequester carbon for centuries. If shade-tolerant species that predominate late in succession maintain high assimilation-to-respiration ratios in other forests, we may be underestimating production in old forests, and current models may underestimate the importance of mature forests as carbon sinks for atmospheric CO2 in the global carbon cycle.
An Unheated Four-Bar Infrared Test Target

A four-bar infrared test target has been built to test the feasibility of using perforated ambient temperature plates for the four bars instead of the customary plates operated at temperatures different from ambient. Six different sizes of four-bar arrays provide six different spatial frequencies. Front and back arrays of perforated plates are moved relative to one another by a motor drive to expose more or less of a sky reflector backplate, thereby producing a varying apparent temperature differential between the bars and their interstices. The target system also features a radiometric monitor which mechanically servos the bar patterns to compensate for changes such as dust or clouds. Qualitative tests with infrared imaging systems show satisfactory bar patterns which disappear when the perforations are closed. Quantitative tests show that differential temperature accuracies of about one tenth of a kelvin can be attained.
Reconstruction of asymmetric vessel lumen from two views

We have developed a technique based on epipolar geometry which allows reconstruction of vessel lumina containing asymmetries for arbitrary lumen orientation. Vessel centerlines and the imaging geometry are determined using previously described methods. Epipolar planes are established for pairs of centerline points and intensity profiles are extracted along epipolar lines. Extracted profiles are fitted to projection curves corresponding to elliptical cross-sections. The original vessel intensity profile is subtracted from the best-fit profile yielding the plaque profile. Corresponding best-fit profiles are used to reconstruct elliptical cross sections by backprojecting and identifying ray intersection points which lie within the model cross section. Assuming that the deformation of an otherwise elliptical lumen occurs as a result of plaque growing inward from the periphery, asymmetries are generated by deforming the cross sections to an extent consistent with the plaque profile in both views. The three-dimensional lumen may be obtained by combining individual cross sections in consecutive epipolar planes. The technique was evaluated using noiseless simulated angiograms. Reconstructed asymmetric lumen cross sections were found to be accurate to 95%, where accuracy was determined using area and distance criteria.
The Product of the Drosophila Gene, Glued, Is the Functional Homologue of the p150Glued Component of the Vertebrate Dynactin Complex

p150Glued is the largest polypeptide in the dynactin complex, a protein heteromultimer that binds to and may mediate the microtubule-based motor cytoplasmic dynein. Cloning of a cDNA encoding p150Glued from rat revealed 31% amino acid sequence identity with the product of the Drosophila gene, Glued. A dominant Glued mutation results in neuronal disruption; null mutations are lethal. However, the Glued gene product has not been characterized. To determine whether the Glued polypeptide is functionally similar to vertebrate p150Glued, we characterized the Glued protein in the Drosophila S-2 cell line. Antibodies raised against Glued were used to demonstrate that this protein sediments exclusively at 20 S, and associates with microtubules in a salt- and ATP-dependent manner. Immunoprecipitations from S-2 cytosol with the anti-Glued antibody resulted in the co-precipitation of subunits of both cytoplasmic dynein and the dynactin complex. An affinity column with covalently bound Glued protein retained cytoplasmic dynein from S-2 cytosol. Based on these observations, we conclude that Glued is a component of a dynactin complex in Drosophila and binds to cytoplasmic dynein, and therefore the mutant Glued phenotypes can be interpreted as resulting from a disruption in the function of the dynactin complex.
Image motion estimation from motion smear-a new computational model

Motion smear is an important visual cue for motion perception by the human vision system (HVS). However, in image analysis research, exploiting motion smear has been largely ignored. Rather, motion smear is usually considered as a degradation of images that needs to be removed. In this paper, the authors establish a computational model that estimates image motion from motion smear information-"motion from smear". In many real situations, the shutter of the sensing camera must be kept open long enough to produce images of adequate signal-to-noise ratio (SNR), resulting in significant motion smear in images. The authors present a new motion blur model and an algorithm that enables unique estimation of image motion. A prototype sensor system that exploits the new motion blur model has been built to acquire data for "motion-from-smear". Experimental results on images with both simulated smear and real smear, using the authors' "motion-from-smear" algorithm as well as a conventional motion estimation technique, are provided. The authors also show that temporal aliasing does not affect "motion-from-smear" to the same degree as it does algorithms that use displacement as a cue. "Motion-from-smear" provides an additional tool for motion estimation and effectively complements the existing techniques when apparent motion smear is present.
On Describing a Student's Cognitive Structure

For several decades, a model has been developing which depicts the learning process in terms of interaction between a student's cognitive structure and the structure of the discipline being studied. There arc a number of conceptual difficulties here that are trapping researchers in cognitive psychology, especially the problem of not confounding the two types of structure. Doubts can even be raised about the usefulness of the notion of cognitive structure as it is presently developed. Throughout the paper, insights from recent relevant philosophical work are used to throw light on the empirical research that is being carried out.
A 6-item brief measure for assessing perceived control of asthma in culturally diverse patients

Background A concise yet accurate measurement tool is needed for use in research and practice in asthma self-management perceptions across culturally diverse patient populations. Objectives To evaluate the psychometric properties of the 11-item Perceived Control of Asthma Questionnaire (PCAQ) and to derive a brief, psychometrically sound, and culturally sensitive measure using item response theory. Methods The PCAQ was administered as one of a battery of measures to 375 adults with asthma as part of an ongoing larger project studying asthma disparities. Analyses of differential item functioning (DIF) were conducted to detect the effects of sex, race/ethnicity, and health literacy on psychometric properties. Results Forty-eight percent of the sample was non-Hispanic white and 44% was African American. The mean ± SD age was 43.7 ± 13.7 years. The derived 6-item version, with 5 DIF items not scored, correlated highly with its full version ( r = 0.903; P Conclusions The 6-item PCAQ short form has the potential to maintain scale integrity while reducing administration time and lessening survey fatigue in studies using multiple questionnaires. DIF analyses also enabled us to understand the unique aspects of perceived asthma control in demographic groups most affected by asthma.
Explicit examples of nonsolvable weakly hyperbolic operators with real coefficients

We give in this paper two explicit examples of nonsolvable weakly hyperbolic operators with real coefficients in two-space-dimensions.
Said Nursi and Maulana Ilyas : Examples of Pietistic Spirituality among Twentieth-Century Islamic Movements

Abstract The premise of this article is that we can learn something about the spirituality as well as other orientations of Bediuzzaman Said Nursi and the movement he inspired by taking a comparative perspective. Among other twentieth-century movements in the Muslim world, it has been suggested that the ‘faith’ movement of Maulana Muhammad Ilyas, also known as the Tablighi Jamaat, would be the most apt for comparison. This study therefore highlights comparable and contrasting aspects of these two movements in order to shed light on Nursian spirituality. It will consider, for example, the lives of the founders, the contexts in which their activities arose, their teachings and practices, and the subsequent development of the respective movements.
Period-doubling bifurcations and chaotic motion for a parametrically forced pendulum

A parametrically forced pendulum is studied numerically both with and without friction. In both cases, period-doubling sequences of bifurcation are found. In the dissipative case, the period-doubling sequence leads to strange attractors, while in the conservative case, the sequence is responsible for the destruction of stable zones.
Self-gravitating Gaseous Bars. I. Compressible Analogs of Riemann Ellipsoids with Supersonic Internal Flows

We present two steady state models of compressible, self-gravitating three-dimensional fluid configurations with triaxial structures and supersonic internal motions. Both models have been constructed via dynamical simulations, starting from rapidly rotating, axisymmetric polytropic configurations that were dynamically unstable toward the development of a barlike or two-armed spiral structure. The two initial models differed mainly in their angular momentum distributions: one had the same specific angular momentum profile as a uniformly rotating, uniform-density sphere; the other had uniform vortensity. In both cases, the nonlinear development of the instability resulted in the formation of a triaxial configuration that was spinning with a well-defined pattern speed and exhibited strongly differential, internal motions. As viewed from a frame rotating with the pattern frequency of the system, the final configurations are in steady-state, in the sense that their structures are unchanging on a dynamical time scale, and appear to be dynamically stable. In both models, a "violin-shaped mach surface" and a pair of weak standing shock fronts appear to be integral components of the steady-state flow. By all accounts, these models are compressible analogs of Riemann S-type ellipsoids. Their steady state configurations are relevant to self-consistent models of galaxies, rapidly spinning compact stellar objects, and the structure and evolution of protostellar gas clouds.
Complimentary role of superconducting electronics in the context of competing microelectronics and optoelectronics

COMPLIMENTARY ROLE OF SUPERCONDUCTING ELECTRONICS IN THE CONTEXTOF COMPETING MICROELECTRONICS AND OPTOELECTRONICSR. SinghDepartment of Electrical and Computer EngineeringClemson UniversityClemson, SC 29631ABSTRACTIn this paper, we have shown that superconducting electronics can provide a complementary role to microelectronics andoptoelectronics. High temperature superconductors can be used in the fabrication of ultra fast three terminal devices as well asfor chip-to-chip interconnections. If the next generations of DRAMs require cooling at 77 K, high temperature superconductorsoffer several advantages over metals as the interconnect material. A new photoeffect reported in this paper can give rise to newdevices and can be used to couple microwave and optoelectronic technology. Major challenge is to develop a low temperatureprocessing technology that is compatible to semiconductor industry. Experimental results are presented indicating the potentialof rapid isothermal processing assisted metalorganic chemical vapor deposition (MOCVD) method as a technique suitable formanufacturing.
Reliability of conventional and new pulse oximetry in neonatal patients.

OBJECTIVES: Pulse oximetry is widely used in the NICU, but clinicians often distrust the displayed values during patient motion, i.e., questionable oxygen saturation (SpO2) and pulse rate (PR) values. Masimo Corporation (Irvine, CA) has developed pulse oximetry with claims of resistance to sources of interference. To test this premise, we compared the performance of the Masimo SET pulse oximeter to a conventional device, Nellcor N-200, and then with three other new-generation pulse oximeters, Nellcor N-395, Novametrix MARS, and Philips Viridia 24C. STUDY DESIGN: We studied 26 nonsedated NICU infants who were on supplemental oxygen and/or mechanical ventilation. ECG heart rate (HR) from a bedside monitor and SpO2 and PR from the two pulse oximeters were captured by a PC for a total of 156 hours. The ECG HR and pulse oximeter spectral waveform were analyzed at alarms for hypoxemia (SpO2≤85%) and/or bradycardia (HR≤80 bpm). We then compared the performance of the Masimo SET to three other new-generation pulse oximeters, Agilent Viridia 24C, Nellcor N-395, and Novametrix MARS, in a similar population of seven infants for a total of 28 hours. We added to the test criteria the ability of the various pulse oximeters to track acute changes in HR. RESULTS: Compared with Nellcor, Masimo SET had 86% fewer false alarms, which also were shorter in duration, resulting in 92% less total alarm time. Masimo SET also identified nearly all bradycardias versus 14% for the Nellcor. Compared with the new-generation pulse oximeters, false desaturations, data drop-outs, and false bradycardias were lowest for Masimo SET, as was the capture of true desaturations and bradycardias. Notably, the new-generation devices differed greatly in their ability to detect changes in HR (i.e., the frequency of frozen PR during times of ECG HR change was 0, 6, 11, and 46 for Masimo, Nellcor, Philips, and Novametrix, respectively). CONCLUSIONS: Masimo SET pulse oximetry recorded markedly fewer false SpO2 and PR alarms and identified more true hypoxic and bradycardic events than either conventional or other new-generation pulse oximeters. Masimo SET also most closely reflected the ECG rate irrespective of accelerations or decelerations in HR. SPECULATION: Routine use of Masimo SET pulse oximetry in the NICU could improve clinician confidence in the parameter leading to more judicious titration of oxygen with possible reductions in hypoxic (e.g., pulmonary hypertension) and hyperoxic (e.g., retinopathy of prematurity) pathology. Additionally, a more trustworthy technology should equate with fewer confirmatory arterial blood gas analyses (less blood loss), and faster weaning from the mechanical ventilation (less chronic lung disease).
Should surgical recertification reflect subspecialization

onping tion The efercertiy in difesrs of ust s prior y succ ires d (eg, v what c gery k the p who h ue to r area i or a l hirdp learly w ecord i that d surg hom m in a v so r nd it d t in w how w d by r ry. F cat linic ent f cted t the s d for s alty a l P n 2 t g o o ost practitioners who become certified in general surg ltimately build clinical practices that are more speciali ocusing in a particular area. Regardless, they must ecertified in general surgery, even though the recertifi ion process may provide only a limited assessment o ype or quality of surgery that they actually perform ay-to-day practice. In order to offer quality assuranc he public and ensure that surgeons are up to date in th n which they have focused their practice, it may be ti ake another look at the recertification process for gen urgery. The American Board of Surgery was established in 1 s part of a national movement aimed at certifying pecialists in a variety of medical disciplines. Such spe sts are distinguished from more poorly qualified pract ers on the basis of extensive training and experience i pecialty area and b y having passed a rigorous examin ion in the area. For certification in general surg andidates must show understanding of a central cor nowledge embracing anatomy, physiology, metabolism mmunology, nutrition, pathology, wound healing, sho nd resuscitation, intensive care, and neoplasia. Cog ive knowledge and practical experience must be sho n each of 10 essential content areas: alimentary t bdomen and its contents; breast, skin, and soft tis ndocrine system; head and neck surgery; pediatric ery; surgical critical care; surgical oncology; traum urns; and vascular surgery. To verify that board-certified general surgeons are c inuing to provide excellent patient care as well as kee breast of recent developments in the field, recertifica ecame mandatory for surgeons certified after 1976. merican Board of Surgery has expressed a strong pr nce that all surgeons who originally held a primary cation in general surgery should continue to recertif eneral surgery, regardless of subspecialization. The can ate for recertification must show a commitment to pro ion growth and learning by the completion of 100 hou ontinuing medical education relevant to surgery and m
Emissivity-correcting near-UV pyrometry for group-III nitride OMVPE.

Abstract We developed a pyrometer that operates near the high-temperature bandgap of GaN, thus solving the transparency problem once a ∼1 μm thick GaN epilayer has been established. The system collects radiation in the near-UV (380–415 nm) and has an effective detection wavelength of ∼405 nm. By simultaneously measuring reflectance we also correct for emissivity changes when films of differing optical properties (e.g. AlGaN) are deposited on the GaN template. We recently modified the pyrometer hardware and software to enable measurements in a multiwafer Veeco D-125 OMVPE system. A method of synchronizing and indexing the detection system with the wafer platen was developed; so signals only from the desired wafer(s) could be measured, while rejecting thermal emission signals from the platen. Despite losses in optical throughput and duty cycle we are able to maintain adequate performance from 700 to 1100 °C.
Suicidal behavior and sexual/physical abuse among street youth

Abstract Objective: To examine the relationship between home life risk factors and suicide attempts among homeless and runaway street youth recruited from both shelters and street locations in Denver, CO; New York City; and San Francisco, CA. Method: Street youth 12–19 years old ( N = 775) were recruited by street outreach staff in Denver, New York City and San Francisco in 1992 and 1993 and interviewed. Cross-sectional, retrospective data were analyzed to examine the relationship between suicide attempts and antecedent home life variables. Logistic regression was used to identify factors predicting suicide attempts. Results: Forty-eight percent of the females and 27% of the males had attempted suicide. The mean number of suicide attempts was 6.2 ( SD = 12.9) for females and 5.1 for males ( SD = 7.6). Among females, 70% reported sexual abuse and 35% reported physical abuse. Among males, 24% reported sexual abuse and 35% reported physical abuse. Sexual and physical abuse before leaving home were independent predictors of suicide attempts for females and males. Other home life factors hypothesized to be risk factors for suicide attempts were not significant. Interaction terms were not significant. Among street youth who were sexually or physically abused in this sample, the odds of attempting suicide were 1.9 to 4.3 times the odds of attempting suicide among those not sexually or physically abused. Conclusions: Interventions attempting to reduce risky behaviors in this population must include assessments of suicidal behaviors as well as components for assisting youth in dealing with the behavioral and emotional sequelae of physical and sexual abuse.
Chemotherapy for small cell lung cancer.

Abstract There were approximately 42,000 new cases of small cell lung cancer (SCLC) in 2002. Despite its initial sensitivity to chemotherapy, only 10% of all SCLC patients will have significant long-term survival. Studies have yet to show significant survival advantages for maintenance chemotherapy, and it appears that four to six cycles of chemotherapy is as effective as longer durations. As yet, there is no defined role for dose escalation in the treatment of SCLC. No one chemotherapy combination has exhibited a definitive survival advantage in extensive disease, although it appears that single-agent oral etoposide may be inferior to combination intravenous chemotherapy. In limited disease, however, cisplatin plus etoposide alone or in alternation with cyclophosphamide/doxorubicin/vincristine is superior to other approaches. There are several new agents with significant activity in SCLC awaiting further study. Semin Oncol 30:9-25. Copyright 2003, Elsevier Science (USA). All rights reserved.
Light scattering study of a twist grain boundary liquid crystal.

Dynamic light scattering is used to probe the fluctuation modes of a liquid crystal exhibiting twist grain boundary (TGB) structure. At the chiral nematic to proposed ``chiral line liquid'' phase transition, anomalous temperature dependence in the fluctuation spectrum and an instability in the helicoidal director structure signify developing TGB order. At lower temperatures, the behavior of the smectic layer-director fluctuations (``soft'' mode) indicates that the previously identified commensurate ${\mathrm{T}\mathrm{G}\mathrm{B}}_{A}$ phase may in fact be a ${\mathrm{T}\mathrm{G}\mathrm{B}}_{C}$ phase with an unusually small tilt angle.
Wafer Bonding for Hybrid Circuit Technology Using Solid-State Reactions

In this study, we report a new wafer bonding technique for the integration of GaAs- and InP-based optical devices with prefabricated Si electronic devices in hybrid circuit technology. This technique uses a Au-Ge eutectic alloy as the bonding materials between GaAs and Si wafers, and between InP and Si wafers. This process takes advantage of the low temperature solid-state reactions at GaAs/Au-Ge, InP/Au-Ge, and Si/Au-Ge interfaces. The bonding was carried out by annealing the samples at 280-300°C in an alloying furnace. The reliability of the joined wafers was evaluated by both cleavage test and standard thermal cycling test. The joining interfaces were characterized by scanning electron microscopy and transmission electron microscopy. The results reveal that the bonding is achieved by low temperature reactions at the GaAs/Au-Ge and InP/Au-Ge interfaces as well as solid-phase epitaxial regrowth at the Si interfaces. The joined structure has very good integrity.
Intelligent computational assistance for experiment design

We have developed an automated system for the design of laboratory experiments in molecular biology. The system uses a planning method known as skeletal plan refinement that attempts to emulate the human cognitive task of experiment design. This paper describes the theory, history, and implementation of the design system and illustrates its function in the domain of DNA cloning experiments.
New aromatic silicon-containing polyamides

The experiments described were aimed at studying systematically the effect of silyl linkages on the thermogravimetric and thermomechanical properties of aromatic polyamides. Specifically, 18 aromatic silicon-containing polyamides were synthesized via interfacial polymerization of six silicon-containing diacid chlorides with 3,3-prime-diaminodiphenylmethane, 3,3-prime-diaminobenzophenone, and 1-(3-prime-aminobenzyl)-4-(3-double prime-aminobenzoyl)benzene. All polyamides were soluble in m-cresol and N,N-dimethylacetamide, and had glass transition temperatures between 178 and 254 C. Thermogravimetric analysis conducted in static air on film specimens showed 5 and 10 percent weight losses between 331 and 400 C and 354 and 440 C, respectively. The potential gain in processability engendered by incorporation of silane substituents was offset in most cases by substantial losses in thermo-oxidative stability.
Room temperature phosphorescence of aromatic hydrocarbons in aqueous micellar solutions

Abstract The phosphoresence spectra of several simple arenas, pyrene, naphthalene, biphenyl and their brominated derivatives have been observed in aqueous micellar solutions at room temperature. The success of these experiments is due to the protective screening of the arene triplet state by solubilization in the micelles. Impurities in the aqueous phase are thus excluded from the excited arene. Small traces of oxygen efficiently remove the phosphorescence as oxygen readily penetrates into the micelle to quench the arene triplet. Hydrophilic quenchers such as Cu2+ and Tl+ also reduce the lifetime of the phosphorescence. In anionic micelles these quenchers are located at the surface of the micelle and efficient quenching take place at the lipid water interface. Cupric ions reduce the lifetime and yield of phosphorescence, while Tl+ ions reduce the lifetime but also enhance the rate of emission of the phosphorescence via heavy atom spin orbit coupling. The technique and data are relevant to the measurement of kinetic parameters in micelles and membranes.
Paroxetine versus nortriptyline in the continuation and maintenance treatment of depression in the elderly

Elderly depressed patients are vulnerable to recurrence of depression and benefit from long-term antidepressant therapy. Physicians increasingly use selective serotonin re-uptake inhibitors (SSRIs) as maintenance therapy, although in the absence of data showing that SSRIs are as efficacious as tricyclic antidepressants (TCAs) in the prevention of depression relapse and recurrence. Our objective was to evaluate, in an open trial, the efficacy of paroxetine versus nortriptyline for preventing recurrence of depression in the elderly. Elderly patients with major depression were randomly assigned in a double-blinded fashion to receive either paroxetine or nortriptyline for the acute treatment of depression. Patients who did not respond or tolerate their assigned medications were crossed over openly to the comparator agent. Patients whose depression remitted continued antidepressant medication (paroxetine n = 38; nortriptyline n = 21) during an open 18-month follow-up study. We examined the rates of and times to relapse and to termination of treatment for any reason. Paroxetine (PX) and nortriptyline (NT) patients had similar rates of relapse (16% vs. 10%, respectively) and time to relapse (60.3 weeks vs. 58.8 weeks, respectively) over 18 months. A lower burden of residual depressive symptoms and side effects during continuation and maintenance treatment was evident in nortriptyline-treated patients. Paroxetine and nortriptyline demonstrated similar efficacy in relapse and recurrence prevention in elderly depressed patients over an 18-month period.
Seasonal and low frequency variations in dynamic height anomaly and transport of the Gulf Stream

Abstract One hundred and thirty pairs of hydrographic stations bracketing the Gulf Stream between Cape Hatteras and the New England Seamounts are used to study seasonal and low frequency changes in dynamic height and baroclinic transport. The data span a 56-year period from 1932 to 1988. The stations were selected from hydrographic sections as representative of conditions immediately outside the current on the Slope Water and Sargasso Sea sides. It is found that the dynamic height anomaly is maximum in the fall and it is almost entirely governed by the annual heating and cooling cycle. The baroclinic transport is calculated from the potential energy anomaly difference between stations located just outside of the northern and southern edges of the Gulf Stream. The annual cycle in the 0–2000 dbar baroclinic transport is maximum in early summer, with a peak to peak range of (8 ± 3) Sv. Low frequency changes in transport, after removing the annual cycle, arc difficult to discern with confidence due to eddy variability. However, there is evidence of a 6 Sv decrease in transport between the late 1950s and early 1970s.
Fourth-Order Blood Pressure Waves

A critically ill 80-year-old man had blood pressure waves with a period of about 30 minutes. These blood pressure oscillations, lasting longer than 18 hours, were accompanied by oscillations in heart rate, central venous pressure, pulmonary arterial pressure, and oxygen saturation of mixed venous blood. No discernible variations in external conditions caused the oscillations. Oscillations with such long periods heretofore have not been reported.
Differentially regulated immediate early genes in the rat uterus.

Estrogen stimulates cellular proliferation in the luminal epithelium, stroma, and smooth muscle of immature rat uterus. Progesterone administered concurrently with estrogen blocks the stimulatory effect of estrogen specifically in the epithelium, whereas progesterone administered alone stimulates proliferation in the endometrial stroma and myometrium. The present studies determined the effects of estrogen and progesterone on expression of the growth-associated, immediate early genes c-fos, c-jun, and jun-B in the luminal epithelium of the uterus. Hormonal effects were quantitated by Northern analysis of RNA extracted directly from the uterine luminal epithelium. Estrogen stimulated c-fos and jun-B expression, but repressed c-jun mRNA levels in the epithelium. In contrast, when whole organ RNA extracts were analyzed, estrogen increased mRNA levels for all three genes. Although progesterone administered alone showed no effect on mRNA levels in either epithelial or whole uterus extracts, it did attenuate the...
Enzymatic synthesis of dilactone scaffold of antimycins.

Antimycins are a family of natural products possessing outstanding biological activities and unique structures, which have intrigued chemists for over a half century. The antimycin structural skeleton is built on a nine-membered dilactone ring containing one alkyl, one acyloxy, two methyl moieties, and an amide linkage connecting to a 3-formamidosalicylic acid. Although a biosynthetic gene cluster for antimycins was recently identified, the enzymatic logic that governs the synthesis of antimycins has not yet been revealed. In this work, the biosynthetic pathway for antimycins was dissected by both genetic and enzymatic studies for the first time. A minimum set of enzymes needed for generation of the antimycin dilactone scaffold were identified, featuring a hybrid nonribosomal peptide synthetase (NRPS)-polyketide synthase (PKS) assembly line containing both cis- and trans-acting components. Several antimycin analogues were further produced using in vitro enzymatic total synthesis based on the substrate pro...
Oceanographic Research at the Scripps Institution of Oceanography

Improvements—During the past year, by means of funds contributed by R. P. Scripps and from the estate of Miss Ellen B. Scripps, the Scripps Institution of Oceanography has been able to replace the gasoline-engine on its boat Scripps with a Diesel engine, and to make numerous improvements. Now, living conditions on the boat are better than they have been before and the boat is equipped to do all of the ordinary oceanographic work to a depth of about 5000 meters. Henceforth, it will be possible to make expeditions to a distance of between five and six hundred miles offshore. Expeditions and oceanographic data—During the past year, in addition to numerous short trips offshore from San Diego or La Jolla, one cruise was made on the Scripps from La Jolla to San Clemente Island, thence to Santa Catalina and Balboa, and back to La Jolla. A series of stations was occupied for various oceanographic purposes, one of which included the collection of core-samples of bottom-deposits for chemical and bacterial investigation. R. H. Fleming spent about three months aboard the naval vessel Hannibal in the Gulf of Panama and off the coast of Costa Rica. He assisted in making oceanographic observations and collecting water-samples at 127 stations. While aboard the vessel he made numbers of chemical analyses for oxygen and phosphate, and collected surface plankton-samples. A report on the results is in preparation. Roger Revelle was aboard the United States Coast and Geodetic Survey steamer Pioneer for ten days during July and assisted in making nine vertical sections for salinity and temperature off Point Arguello. He also made oxygen-sections at each station occupied and collected bathypelagic organisms to study the interrelations between the vertical distribution of zooplankton and the oxygen-content of the water.
Large-scale fabrication of periodic nanostructured materials by using hexagonal non-close-packed colloidal crystals as templates.

This letter reports a versatile nonlithographic technique for mass fabricating three types of technologically important materialspolymer microwell arrays, 2D-ordered magnetic nanodots, and semiconductor nanopillar arrays, each with high crystalline qualities and wafer-scale sizes. Spin-coated hexagonal non-close-packed silica colloidal crystals embedded in a polymer matrix are used as starting templates to create 2D polymeric microwell arrays. These through-hole arrays can then be used as second-generation templates to make periodic magnetic nanodots and semiconductor nanopillars. This self-assembly approach is compatible with standard semiconductor microfabrication, and complex micropatterns can be created for potential device applications. The wafer-scale technique may find important applications in biomicroanalysis, high-density magnetic recording media, and microphotonics.
SU‐FF‐T‐372: Novel Neutron Dosimetry Using Radiochromic Films for 10 MeV Neutrons

The purpose of this paper is to estimate neutron doses using radiochromic XRQA films. Five radiochromic films, placed at varying distances from the neutron source and a water bottle, were exposed to a flux of 10 MeV neutrons produced via the d(d, n)He reaction using the Tandem accelerator at Triangle Universities Nuclear Laboratory at Duke University. An estimation of the neutron flux was obtained by neutron activations of two sets of aluminum and gold activation foils. One foil of each type was placed at the front and back sides of the water target. The flux calculation was based on gamma spectroscopy of the irradiated foils using HPGe detectors. A Monte Carlo(MC) simulation based on FLUKA2008 code was also used to estimate the 10 MeV neutron dose for the same geometry. The accuracy of the results from MC was verified by the comparison of dose on water target from MC with the dose calculated on the same target using flux and the ICRU data tables. Based on these results, a calibration curve was obtained for optical density of the film vs. absorbed neutron dose in the range of 0–20 Gy. We have demonstrated the potential application of radiochromic films for neutrondosimetry. This research was, in part, supported by National Institute of Allergy and Infectious Diseases Grant 5U19 AI067798‐03
Computational lithography: the new enabler of Moore's Law

There have been many pronouncements about the slowing down of Moore's Law. Human enterprise, however, has managed to disprove these dim prophecies by producing ingenious solutions on a regular basis, to allow Moore's Law to continue its unabated march. The goal of this paper is to suggest that the innovation pipeline is rich enough to maintain this trend for the foreseeable future. One such innovation, involving pixelated masks, was announced by Intel in June 2007. This technology was created to address the problem caused by the growing gap between the lithography wavelength and the feature sizes patterned with it. As this gap has increased, the quality of the image has deteriorated. About a decade ago, Optical Proximity Correction (OPC) was introduced to bridge this gap, but as this gap continued to increase, one could not rely on the same basic set of techniques to maintain image quality. The computational lithography group at Intel sought to alleviate this problem by experimenting with additional degrees of freedom within the mask. This paper describes the resulting pixelated mask technology.
Effects of Toys on the Play Quality of Preschool Children: Influence of Gender, Ethnicity, and Socioeconomic Status

This study examined the effects of nine toys on the play of 60 3- and 4-year-old children in culturally diverse preschool classrooms. The toys, which varied in their features and intended uses, were selected from a list of those that were nominated by teachers and parents as being developmentally beneficial. Each toy was video recorded for 240 h during free play time in four different classrooms. Researchers coded 828 two-minute segments of children’s play with these toys using a play quality with toys (PQT) rating instrument developed in a previous investigation. Toys were found to vary significantly in their impact on play quality. PQT scores were also found to vary for each toy depending on the gender, socioeconomic status, and ethnicity of the child playing with it, and the length of time it was available in the classroom. Implications for selecting toys for classrooms and observing children’s play with them are presented.
A Comparative Study of the Empirical Mode Decomposition and Wavelet Analysis on Their Application for Structural Health Monitoring

The paper presents a comparative study of the effectiveness of three novel damage detection techniques namely Continuous Wavelet Transform (CWT), Empirical Mode Decomposition (EMD) and Wavelet Packet Sifting (WPS). The health condition of a mechanical or civil engineering structure can be assessed by monitoring a change in natural frequencies and mode shapes. CWT method can be used to identify the instantaneous values of these modal parameters by the wavelet ridges. Using the EMD method, intrinsic mode functions (IMF) can be sifted from a vibration signal, whereas a newly-developed WPS technique can decompose a signal into its dominant mono-frequency components. Instantaneous modal information can be extracted by incorporating the EMD and WPS with the Hilbert Transform. These techniques are illustrated for simulated vibration data from a three-degree-of-freedom system subjected to (i) sudden damage and (ii) progressive damage. The aspects related to the implementation algorithms, sensitivity to damage type and the robustness issues in case of noisy data are discussed. In case of progressive damage, all methods performed well. WPS technique performed better in case of sudden damage whereas CWT demonstrated robustness in case of noisy data.Copyright © 2004 by ASME