cssi/SciSciGPT-SciSciNet huggingface dataset:
Using ROC curves to assess the efficacy of several detectors of damage-induced nonlinearities in a bolted composite structure

Abstract We offer a comparison of several different detectors of damage-induced nonlinearities in assessing the connectivity of a composite-to-metal bolted joint. Each detector compares the structure's measured vibrational response to surrogate data, conforming to a general model for the healthy structure. The strength of this approach to detection is that it works in the presence of certain types of varying ambient conditions and is valid for structures excited with any stationary process. Here we employ several such detectors using dynamic strain response data collected near the joint as the structure was driven using simulated wave forcing (taken from the Pierson–Moskowitz frequency distribution for wave height). In an effort to simulate in situ monitoring conditions the experiments were carried out in the presence of strongly varying temperatures. The performance of the detectors was assessed using receiver operating characteristic (ROC) curves, a well known method for displaying detection characteristics. The ROC curve is well suited to the problem of vibration-based structural health monitoring applications where quantifying false positive and false negative errors is essential. The results of this work indicate that using the estimated auto-bicoherence of the systems response produced the best overall detection performance when compared to features based on a nonlinear prediction scheme and another based on information theory. For roughly 10% false alarms, the bicoherence detector gives nearly 90% probability of detection (POD). Conversely, for several of the other detectors 5–10% false alarms leads to ∼ 70 % POD. While the bicoherence (and bispectrum) have been used previously in the context of damage detection, this work represents the first attempt at using them in a surrogate-based detection scheme.
Determination of Verapamil Enantiomers in Serum Following Racemate Administration Using HPLC

Abstract A method for quantitation of (+) -(R) -verapamil and (-)-(S)-verapamil concentrations in serum was developed for the purpose of determining verapamil enantiomer pharmacokinetics after racemate administration. Two high-performance liquid chromatographic (HPLC) systems were used. A reversed-phase HPLC system was first used to quantitate summed concentrations of the enantiomers ((R+S)-verapamil) using fluorescence detection. Mobile phase eluate containing the (R+S)-verapamil was collected from the detector outlet, and the individual enantiomers in the residue were separated using a chiral column with a stationary phase of silica-bound α1-acid glycoprotein. Peak heights were measured and peak height ratios of R/S were determined. The measured (R+S)-verapamil concentration from the achiral system was used with the R/S ratio from the chiral system to determine the serum concentrations of the individual enantiomers. The pharmacokinetics of (+)-(R)-verapamil and (-)-(S)-verapamil were studied in a health...
Motional Narrowing in Monolayer 3He Film NMR

Recent specific heat measurements1–3 of monolayer helium films adsorbed on graphite have revealed striking new behavior. These measurements, as well as adsorption isotherms,4 indicate that the graphite basal plane presents a particularly homogeneous surface for adsorption. The NMR measurements reported here were made with the intention of (1) continuing the study of monolayer helium film properties revealed by the heat capacity measurements using a different experimental technique, and (2) investigating the NMR in two dimensions for a monatomic, chemically inert system on a homogeneous substrate.
The missing family: Staff perspectives on and responses to familial noninvolvement in two diverse nursing homes

Although the continuum of familial involvement with nursing home residents includes those who are deeply engaged and those who are totally absent, little is known about how staff perceive and react to family noninvolvement. This article explores staff perspectives on and responses to family absence. Semistructured interviews were conducted with 52 employees and 18 residents from two NHs, one an urban facility with a largely chronic mentally ill population and the other a rural, tribally owned facility with a predominately cognitively impaired American Indian clientele. Medical record reviews were also conducted. Staff theories of family absence were informed primarily by dominant American and American Indian cultural values regarding kinship, psychiatric disorders, and institutionalization. In each facility, metaphoric kinship relationships between staff and residents compensated somewhat, but not entirely, for perceived family noninvolvement. This research highlights the cultural variability of staff perspectives on family absence but also points to similar strategies for coping with it.
Biogeography and diversification of the Pacific ant genus Lordomyrma Emery

Aim This study addresses the origins of terrestrial biodiversity of the Fijian islands using the ant genus Lordomyrma (Hymenoptera: Formicidae: Myrmicinae) as a model system. We derive the evolution of the genus and determine its closest extra-Fijian relatives from geological data, molecular phylogenetic reconstruction and divergence estimates. Location Ant taxa were sampled in the Southwest Pacific, Melanesia, Southeast Asia, Australia and mainland China. Methods Phylogeny and divergence estimates of the ant genus Lordomyrma based on four nuclear genes (28S, ArgK, LW Rh, CAD) plus data on Indo-Pacific geological history are used to address current hypotheses regarding the origins of the Fijian biota. Results The genus Lordomyrma probably originated in mainland Asia, with subsequent colonization of Australia and the Pacific. The Fijian Lordomyrma clade is monophyletic, and originated c. 8.8 Ma, when it diverged from a sister group in Papua New Guinea. Main conclusions The colonization of Fiji by Lordomyrma is probably a result of long-distance dispersal from New Guinea, possibly aided by island hopping across the Vitiaz Arc. The timeline of diversification in Lordomyrma is broadly congruent with the Miocene fragmentation of the Vitiaz Arc and the Pliocene emergence of Vanua Levu. The biotic shuttle hypothesis, which posits ‘Eua Island as the source of Fijian endemics, is rejected based on the sister relationship of Fiji and New Guinea lineages, as well as on the Miocene submergence of the terrane below sea level. The diversity of Fijian Lordomyrma results from the radiation of a single lineage, which diverged from a New Guinea sister group. The genus appears to have originated in Asia rather than in Australia.
Reflections on the computational approximation of elastic incompressibility

Abstract Gradual diminuation of compressibility tied with mesh refinement is shown to be an effective and practical way to numerically cope with near incompressibility of elastic solids. It is remarked that (low order) numerical integration is a side issue in this technique and that (high order) exact integration of high order finite elements can be safely used with the correct minimal variation principle of classical elasticity, including a high Poisson ratio.
Aerodynamic parameters for a sparsely roughened surface composed of small cotton plants and ridged soil

Roughness length (z0) and displacement height (d0) parameters are required in most algorithms that use remotely sensed data to estimate sensible heat and latent heat fluxes at the earth's surface. Estimates of aerodynamic roughness parameters often have large uncertainties, particularly for sparsely-roughened surfaces, such as agricultural row crops early in the growing season. The purpose of this study was to use wind profile data collected at four levels under near-neutral conditions to estimate z0 and d0 for small cotton plants (mean plant height ≈ 0.31 m) growing on 0.16 m high soil ridges in Arizona. Four 24-min periods with near-neutral conditions and wind direction perpendicular to the rows were identified over two days in June 1988. From these periods, a mean z0 ≈ 0.02 m and a mean d0 ≈ 0.23 m were determined. Relative to total obstacle height (h = plant height + ridge height), these values correspond to z0/h ≈ 0.04, and d0/h ≈ 0.50, which differ considerably from previously published values for partial canopy cotton.
Reconstitution and characterization of the human DNA polymerase delta four-subunit holoenzyme

Mammalian DNA polymerase delta was originally characterized as a tightly associated heterodimer consisting of the catalytic subunit, p125, and the p50 subunit. Recently, two additional subunits, the third (p68) and fourth subunits (p12), have been identified. The heterotetrameric human pol delta complex was reconstituted by overexpression of the four subunits in Sf9 cells, followed by purification to near-homogeneity using FPLC chromatography. The properties of the four-subunit enzyme were shown to be functionally indistinguishable from those of pol delta isolated from calf thymus. The physicochemical properties of both the reconstituted heterotetramer and the heterodimer of the p125 and p50 subunits were examined by gel filtration and glycerol gradient ultracentrifugation. These studies show quite clearly that the heterodimer and heterotetramer complexes do not behave in solution as dimeric structures. This issue is of significance because several studies of the yeast pol delta complexes have indicated that the third subunit is able to bring about the dimerization of the pol delta complex. The heterodimer is only weakly stimulated by PCNA, whereas the heterotetramer is strongly stimulated to a level with a specific activity comparable to that of the calf thymus enzyme. These results resolve earlier, conflicting reports on the response of the heterodimer to PCNA. Nevertheless, the heterodimer does have some ability to interact functionally with PCNA, consistent with evidence that the p125 subunit itself has an ability to interact with PCNA. The functional interaction of PCNA with the pol delta complex may likely involve multiple contacts.
Effect of Pb free Alloy Composition on Drop/Impact Reliability of 0.4, 0.5 & 0.8mm Pitch Chip Scale Packages with NiAu Pad Finish

Recent industry data show that the drop/impact reliability of Chip Scale Packages has been detrimentally affected by switching to SAC alloys with Ag percent equal to or greater than 3%. The primary cause of this is attributed to the higher strength and lower ductility of SAC305 and SAC405 alloys compared to SnPb solder, resulting in higher stresses at IMC layers and causing interfacial failures. While previous study [1] focused on Cu OSP finish for the packages, the study reported here is a comprehensive collection of data for NiAu pad finish using various solder alloys. The alloys considered had Ag percent varying from 1.0 to 3.0%, Cu % from 0.1 to 0.7%, and small amount of Ni, In, Co, and Ge addition to the main SAC system. Metallurgical studies were performed on identifying the IMCs and their growth with time and temperature for these alloys. Additionally, a number of board level drop tests (JESD22-B111) were performed on 0.4, 0.5, and 0.8 mm pitch CSP devices using different ball sizes and solder alloys. Finally, the data was compared against the optimum Pb free alloy solution for Cu OSP substrates. The results show that while three element SAC alloy is sufficient of NiAu surface finish, the Ag content has to reduce to gain appreciable increase in drop performance. The effect of Cu % alone in solder alloy was not found to be significant for drop performance improvement. Also, the Sn1.2Ag0.5Cu0.05Ni alloy that worked best for Cu OSP finish [1] did not perform as good as Sn1.0Ag0.5Cu alloy for NiAu finish.
Relation between myocardial oxygen consumption and myocardial blood volume: a study using myocardial contrast echocardiography.

Abstract Myocardial blood volume (MBV) is the volume of blood residing in myocardial vessels, 90% of which is in capillaries. MBV can be measured in vivo using myocardial contrast echocardiography (MCE). It has been shown that when increases in coronary blood flow (CBF) are not associated with increase in myocardial oxygen consumption (MVO 2 ), MBV does not increase. We hypothesized that MBV would increase when increases in CBF are associated with an increase in MVO 2 . The atrioventricular node was ablated in 18 dogs and dual-chamber pacing was instituted. In group 1 dogs (n = 9), heart rate was altered from 50 to 150 bpm −1 in increments of 20 bpm −1 in random order. In group 2 dogs (n = 9), heart rate was kept constant, and dobutamine was infused at doses of 5, 10, 20, 30, and 40 μg/kg −1 /min −1 . During each intervention, hemodynamic parameters and MVO 2 were measured, and MCE was performed. MVO 2 increased more ( P 2 ( P P 2 is increased substantially, the resulting increase in CBF and MCE-derived myocardial blood flow is mediated, in part, by an increase in MBV. Thus, capillary recruitment plays an important role in the physiologic regulation of CBF. Lack of increase in MBV during dobutamine stress may indicate the presence of coronary stenosis or microvascular disease. (J Am Soc Echocardiogr 2002;15:857-63.)
Investigation of the deposition and emission of mercury in arctic snow during an atmospheric mercury depletion event

[1] Mechanisms of air-snow exchange of mercury (Hg) during and after atmospheric mercury depletion events (AMDEs) remain poorly constrained and this has limited our understanding of the arctic Hg cycle. We measured the Hg concentrations of surface snow through time and carried out flux chamber experiments during AMDE and non-AMDE conditions in the spring of 2006 near Barrow, Alaska. Clear skies, low-velocity onshore winds, and a stable boundary layer characterized the meteorology during this AMDE. Surface snow Hg concentrations (upper 1 cm) increased throughout a 9-day AMDE from background levels (4.1–15.5 ng/L) to elevated levels (147 and 237 ng/L) at two sampling sites and returned to near-baseline values within 2 days of AMDE cessation. The Hg concentrations of core samples from the full snowpack did not increase significantly during the AMDE and demonstrate that the Hg enhancement of surface snow resulted from deposition of atmospheric Hg to surface snow. We estimate that complete deposition of background Hg to a height of 200–450 m in the near-surface troposphere could account for the Hg gains to surface snow during this event. Snow incubated in field-based flux chambers emitted 4 to 7% of its total Hg content within 1 day and may represent an upper limit for the photo-reduction rate of “easily” reducible Hg in snow under post-AMDE conditions. Full-column snow core samples collected in the late springtime have comparable Hg loads to those observed during the AMDE season and imply that a significant fraction of the Hg deposited during the 3-month AMDE season was retained until snowmelt at this location.
Pertussis booster vaccine in China.

Vaccination against diphtheria, tetanus, and pertussis (DTP) has achieved great success in infants and younger children in China. However, pertussis booster vaccination in older children, adolescents, and adults has received more attention lately due to the waning immunity that is observed following immunization and, as a result, a resurgence of pertussis in these populations. Under the current national childhood immunization program in China, children will not receive a pertussis booster dose after 2 years of age. Recently, a reduced antigen content diphtheria, tetanus, and acellular pertussis combined vaccine (dTpa) was licensed in China and has been used as the booster dose to children aged 6-12 years. The preferred strategy for pertussis booster vaccination in China would be to substitute dTpa vaccine for the currently recommended combined diphtheria and tetanus vaccine at 6 years of age; however, the availability and accessibility of the dTpa vaccine in China are limited due to insufficient supply an...
RELATIONSHIP OF PLASMA UREA NITROGEN AND UREA-CYCLE AMINO ACID CONCENTRATIONS IN SWINE TO DIETARY ELECTROLYTE BALANCE AND WATER INTAKE'

Abstract Castrated male pigs were used to evaluate effects of dietary electrolyte balance (dEB) and water intake on concentrations of plasma urea nitrogen (PUN) and ureacycle amino acids. In Trial 1, pigs were allowed free access to either a cornsoybean diet as a control or the diet containing 1% Na 2 CO 3 substituted for corn to increase the cation to anion ratio. Added cation (Na) elevated (P 0.10) concentrations of plasma urea-cycle amino acids in the pigs. The studies demonstrate that cation to anion ratio and water intake are factors that should be controlled in design of experiments and interpretation of results when PUN is used to be indicative for the dietary amino acid adequacy.
Optical coherence tomography for ultrahigh resolution in vivo imaging

Optical coherence tomography (OCT) is an emerging biomedical optical imaging technique that performs high-resolution, cross-sectional tomographic imaging of microstructure in biological systems. OCT can achieve image resolutions of 1-15 microm, one to two orders of magnitude finer than standard ultrasound. The image penetration depth of OCT is determined by the optical scattering and is up to 2-3 mm in tissue. OCT functions as a type of 'optical biopsy' to provide cross-sectional images of tissue structure on the micron scale. It is a promising imaging technology because it can provide images of tissue in situ and in real time, without the need for excision and processing of specimens.
Gestos efêmeros e obras tangíveis: a trajetória de Antonio Manuel

Even though related to Brazilian constructivism, Antonio Manuel's artistic production has remained unique, and, sometimes, radical. This article examines the particularities of his work, mainly from the point of view of its relations to neoconcretism's postulates.
THE SURFACE CHEMISTRY OF HYDROCARBONS ON TRANSITION METAL SURFACES: A CRITICAL REVIEW

The catalytic chemical conversion of hydrocarbons on transition metals is at the heart of a good number of processes of industrial importance, including oil and food processing, pharmacological synthesis, manufacturing of specialty chemicals, and polymer production, to name a few. This is an old field that has advanced in great measure by process development work based on trial and error. It has only been in the last few decades, with the advent of a battery of new surface-sensitive techniques, that it has been possible to address the fundamental questions on the basic chemistry behind those hydrocarbon conversion reactions. In this review we highlight some of the main ideas advanced in this field by modern surface-science studies. Particular emphasis is given here to the pioneering work of Professor Somorjai's group as well as our more recent contributions. A discussion is provided on the state of the art of the knowledge available in terms of the elementary steps involved in the transformations of hydrocarbons on metals, as obtained in experiments performed under well-controlled vacuum conditions; on the connection between that knowledge and the reactions that may prevail under the atmospheric pressures encountered in real catalytic processes; and on the key questions that remain unanswered to date and the possible future directions in this area of research.
Locomotor-respiratory coupling patterns and oxygen consumption during walking above and below preferred stride frequency

Locomotor respiratory coupling patterns in humans have been assessed on the basis of the interaction between different physiological and motor subsystems; these interactions have implications for movement economy. A complex and dynamical systems framework may provide more insight than entrainment into the variability and adaptability of these rhythms and their coupling. The purpose of this study was to investigate the relationship between steady state locomotor-respiratory coordination dynamics and oxygen consumption $$ (\dot{V}O_{2}) $$ of the movement by varying walking stride frequency from preferred. Twelve male participants walked on a treadmill at a self-selected speed. Stride frequency was varied from −20 to +20% of preferred stride frequency (PSF) while respiratory airflow, gas exchange variables, and stride kinematics were recorded. Discrete relative phase and return map techniques were used to evaluate the strength, stability, and variability of both frequency and phase couplings. Analysis of $$ \dot{V}{\text{O}}_{2} $$ during steady-state walking showed a U-shaped response (P = 0.002) with a minimum at PSF and PSF − 10%. Locomotor-respiratory frequency coupling strength was not greater (P = 0.375) at PSF than any other stride frequency condition. The dominant coupling across all conditions was 2:1 with greater occurrences at the lower stride frequencies. Variability in coupling was the greatest during PSF, indicating an exploration of coupling strategies to search for the coupling frequency strategy with the least oxygen consumption. Contrary to the belief that increased strength of frequency coupling would decrease oxygen consumption; these results conclude that it is the increased variability of frequency coupling that results in lower oxygen consumption.
The environmental and inner-core conditions governing the intensity of Hurricane Erin (2001)

Abstract The evolution of Hurricane Erin (2001) is presented from the perspective of its environmental and inner-core conditions, particularly as they are characterized in the Statistical Hurricane Intensity Prediction Scheme with Microwave Imagery (SHIPS-MI). Erin can be described as having two very distinct periods. The first, which occurred between 1 and 6 September 2001, was characterized by a struggling tropical storm failing to intensify as the result of unfavorable environmental and inner-core conditions. The surrounding environment during this period was dominated by moderate shear and mid- to upper-level dry air, both caused in some part by the presence of a Saharan air layer (SAL). Further intensification was inhibited by the lack of sustained deep convection and latent heating near the low-level center. The authors attribute this in part to negative effects from the SAL. The thermodynamic conditions associated with the SAL were not well sampled by the SHIPS parameters, resulting in substantial ...
Assessing specific causation of mesothelioma following exposure to chrysotile asbestos-containing brake dust.

Background: The question of whether chrysotile asbestos-containing brake dust can plausibly serve as a cause of mesothelioma in an exposed individual has become a matter of heated debate in the medical literature despite multiple international, federal, and state governmental agencies acknowledging a causal association. Objectives: We describe and provide an analysis of various industry and academic perspectives contributing to the debate. Methods: A framework is presented for evaluating the general and specific causal relationship between brake dust exposure and mesothelioma utilizing the principles of forensic epidemiology, and by applying the Bradford–Hill criteria. Results and conclusions: We conclude that there is a “net” of evidence favoring a causal relationship between brake dust-associated chrysotile exposure and mesothelioma. The industry-sponsored position that there is insufficient evidence to support a contiguous “chain” of causation is specious from both a methodologic and evidentiary perspe...
Sorption and desorption of trace elements bySpartina alterniflora detritus

Element and extractant-specific desorption of Mn, Fe, Cu, and Zn fromSpartina alterniflora detritus was observed. Desorption of a substantial fraction of the total detrital Mn, Fe, Cu and Zn occured rapidly when the detritus was treated with 0.1N HCl or 1 MgCl2. This treatment removed precipitated/coprecipitated and adsorbed trace elements, respectively, suggesting that a large fraction of detritus-bound trace elements are in readily exchangeable, surface reaction sites. The carboxylic acid functional group cation exchange capacity of the detritus also suggests an important role of surface exchange reactions in the dynamics of trace elements during decomposition. The rate and magnitude of changes in the trace element content of detritus has important implications for estuarine biogeochemical cycling of these elements including the potential for biological uptake of trace elements by detritus-consuming fauna.
Research funding: Global challenges need global solutions

Subra Suresh sets out the institutional reforms needed for collaborative action among international research-funding agencies to tackle the challenges humanity faces.
Bounds for effective diffusivities using moment and transport constraints

Abstract Upper and lower bounds for an effective diffusivity characteristic of binary diffusion through a heterogeneous medium are calculated by imposing geometric and transport constraints on the pore size distribution. The method relies upon identifying moment spaces induced by Tchebycheff systems closely related to diffusion experiments and a priori information about the geometry. If statistics beyond the porosity and average pore size are included, temperature dependent tortuosity factors result from the strong coupling between the diffusive flux within a capillary and the pore size distribution. It is shown that hybrid statistical information, such as the porosity and a single diffusion experiment, can delimit significantly the allowed region for extrapolated data.
History of the library.

Demarest (1863–1956), an alumnus (1863) and the president of Rutgers (1906 to 1924 ) and author of the first comprehensive history of Rutgers, The History of Rutgers College (Princeton University Press, 1924 ) , presents a detailed history of the Rutgers library, including finances, personnel, collections acquired and its various locations, from the books made available by Rutgers' first tutors in the 1770s to 1937 when the collections were housed in the Voorhees Library, the first purposely-built library building with holdings of 300,000 volumes.
Measurements of the polarizability of tungsten adatoms on tungsten (110) planes

It is shown that high quality room temperature field ion images can be obtained. Image contrast can be enhanced by using a Ne-Ar mixture. The enhancement is due to field adsorption of argon at room temperature. Using the room temperature FIM, one can observe the movements of individual adatoms on surface planes. Due to the lateral field gradient existing on surface planes, the adatoms generally are forced to migrate in the direction from the center to the edge of the plane. From the migration speed, the polarizability of the adatoms can be calculated. From our analysis and experimental data, the polarizability of tungsten adatoms on a tungsten (110) plane is found to be 9.2 A3. A comparison is made to that obtained from field evaporation rate measurements. Es wird gezeigt, das bei Zimmertemperatur Feldionenbilder (FIM) hoher Qualitat erhalten werden konnen. Der Bildkontrast last sich mit einer Ne–Ar-Mischung steigern. Die Steigerung wird durch eine Feldadsorption von Argon bei Zimmertemperatur hervorgerufen. Mit den Zimmertemperatur-FIM lassen sich die Wanderungen individueller Adatome an Oberflachenebenen beobachten. Auf Grund des lateralen Feldgradienten an den Oberflachenebenen werden die Adatome im allgemeinen gezwungen, in die Richtung vom Zentrum zu den Kanten der Ebenen zu wandern. Aus der Wanderungsgeschwindigkeit kann die Polarisierbarkeit der Adatome berechnet werden. Aus der Analyse und experimentellen Ergebnissen wird die Polarisierbarkeit von Wolfram-Adatomen an einer Wolfram-(110)-Ebene zu 9,2 A3 bestimmt. Es wird ein Vergleich mit den Werten aus Messungen der Feldverdampfungsrate durchgefuhrt.
Quality preservation of organic cottage cheese using oregano essential oils

Abstract Organic cottage cheese was flavoured with four different Argentinean oregano essential oils (EOs) (Compacto, Cordobes, Criollo, and Mendocino) and thymol. Chemical indicators of lipid oxidation, oxidation, and changes in the fatty acid and organic acid profiles were determined during 30 days under thermal storage. The samples flavoured with Cordobes EO and thymol presented lower conjugated dienes (15.94 and 15.53, respectively), whereas the control sample the maximum value (17.54). Values of unsaturated fatty acids decreased significantly ( p
Novelty Helmet Use by Motorcycle Riders in Florida

Although Florida law requires all motorcyclists to wear helmets, 16 percent of all motorcycle drivers and 30 percent of all their passengers killed in motorcycle crashes in 1996 were not wearing protective helmets. In addition, the use of novelty helmets may be on the rise in states with universal helmet laws. The objectives of this research were to determine motorcycle helmet use rates on Florida roadways and to estimate the level of novelty helmet use by motorcycle occupants. A total of 2,498 motorcyclists in 13 Florida counties were observed over a 2-month period. Data were collected on helmet use and type, motorcycle type, gender, and use of other safety equipment. Almost all motorcycle occupants wore some type of helmet; the observed state-level usage rate was 99.5 percent. However, a significant number of these helmets were novelty helmets. The type of helmet motorcyclists choose to wear may be related to the type of motorcycle driven and the gender of the driver and passenger. Overall, novelty helm...
Effect of aging on the shear bond strength of orthodontic brackets.

Introduction: Bracket loss during the later stages of orthodontic treatment is a relatively frequent occurrence. The purpose of this study was to evaluate and isolate the effect of composite aging, one of many factors that can contribute to decreased bond strength during a normal 24-month orthodontic treatment period. Methods: Two orthodontic bonding adhesives—Transbond APC II (3M Unitek, Monrovia, Calif) and Quick Cure adhesive (Reliance Orthodontic Products, Itasca, Ill)—were used to bond brackets to 280 bovine incisors that were stored in distilled water at 37°C for 30 minutes, 24 hours, and 1, 6, 12, 18, and 24 months before shear-peel testing. Results: Bond strength increased over the first 24 hours and then tended to decrease over the next 24 months. The bond strengths (in MPa) for Transbond and Quick Cure, respectively, were as follows: 30 minutes, 14.99 ± 0.75 and 21.02 ± 1.79; 24 hours, 20.99 ± 2.11 and 25.61 ± 1.96; 1 month, 20.54 ± 1.58 and 18.96 ± 1.02; 6 months, 17.77 ± 1.66 and 19.52 ± 1.61; 12 months, 14.79 ± 1.30 and 18.28 ± 1.43; 18 months, 16.08 ± 1.37 and 16.19 ± 1.01; and 24 months, 12.44 ± 1.06 and 8.62 ± 1.03. Conclusions: Shear bond strength of orthodontic brackets increases from 30 minutes to 24 hours and then tends to decrease over the next 24 months. The decrease in bond strength due to the effects of composite aging in water appears to be a major factor in the decreased bond strength seen clinically.
Ultra-large scale integration

Ultra-large scale integration is governed by a hierarchical matrix of limits. The levels of this hierarchy can be codified as 1) fundamental, 2) material, 3) device, 4) circuit, and 5) system. Each level includes both theoretical and practical as well as analogical limits. Theoretically, thermal fluctuations impose a fundamental limit of several kT on switching energy. Scattering limited velocity and critical electric field establish a material limit on switching speed. Avoidance of punchthrough sets a device dimension limit. CMOS power-delay product defines a circuit limit. And, clock skew represents a system limit on ULSI. For conservative design margins, circuit limits project MOSFET channel lengths in the 0.4-0.2 µm range.
Variations in the 3 micron spectrum across the Orion Bar: polycyclic aromatic hydrocarbons and related molecules

Long-slit spectra across the Orion Bar reveal significant differences in the spatial behavior of the components of the 3 microns polycyclic aromatic hydrocarbon (PAH) spectrum. The strong PAH band at 3.29 microns generally decreases exponentially with distance from the ionization front into the molecular cloud (scale height approximately 12"), although excesses appear approximately 10" and 20" behind the ionization front, close to layers of H2 and CO emission, respectively. The 3.40 microns PAH feature separates into two components with very different spatial distributions. The main component (at 3.395 microns), along with the 3.51 microns band and the PAH plateau (3.3-3.6 microns), shows excess emission approximately 10" and approximately 20" behind the ionization front, stronger than the excesses in the 3.29 microns band. The extra component of the 3.40 microns band, which peaks at approximately 3.405 microns, has a spatial distribution very similar to the H2 emission. Aromatic C-H stretches in PAHs most likely produce the 3.29 microns feature. Aliphatic C-H stretches in either attached methyl side-groups or superhydrogenated PAHs, or perhaps both, could produce the complicated spectral and spatial structure at 3.40 microns.
Semantic Encoding in Older Adults As Evidenced by Release From Proactive Inhibition

Wickens' Release from Proactive Inhibition paradigm was used to investigate semantic encoding in healthy older persons, nursing home residents, and college students. Significant PI Release effects, which did not interact with age, were obtained for taxonomic category and semantic differential dimensions. However, older persons, especially nursing home residents, displayed lower percentages of recall than college students, indicating that their semantic processing was less efficient. It was suggested that older and younger adults may differ not so much as their levels (or depth) of encoding as in their degree of elaboration within particular levels.
Studies of lymphocyte subpopulations in the liver tissue and blood of patients with chronic active hepatitis (CAH).

Monoclonal antibodies to antigens on the surfaces of mononuclear cells (MNC) were used to characterize lymphocyte subpopulations infiltrating portal areas and parenchyma of livers in 31 patients with chronic active hepatitis (CAH). The distribution and numbers of infiltrating lymphocytes were determined in serial sections immunostained by the avidin-biotin-peroxidase complex method. T lymphocytes were the major component of inflammatory cells in the portal tracts. In the peripheral blood and portal areas, T helper-inducer(T4+) cells were the more numerous subpopulation. However, the hepatic lobules and areas of “piecemeal” necrosis always contained more T suppressor-cytotoxic (T8+) cells. The latter were demonstrated in contact with HBsAg-containing hepatocytes in tissues of patients with HBsAg-positive CAH. The mean numbers of T lymphocytes infiltrating the portal and periportal areas of livers from patients with HBsAg-negative and HBsAg-positive CAH were not different. Large numbers of B cells forming distinct follicles were seen in tissues from patients with HBsAg-positive CAH. The presence of increased numbers of portal T and B lymphocytes correlated with progressive liver damage as observed in two patients studied at yearly intervals.
Designing solid propellant pulsed plasma thrusters

In this paper fundamental definitions and a few semiempirical correlations of experimental data of solid propellant pulsed plasma thrusters are used to illustrate the design analysis of such propulsion systems. The design analysis presented facilitates the design of a thruster to meet a specific performance level and provides the spacecraft designer with a methodology to select a pulsed plasma propulsion system to meet his mission requirements.
Fluorescent in situ hybridization utilization for high-risk prenatal diagnosis: a trade-off among speed, expense, and inherent limitations of chromosome-specific probes.

Abstract Objective: The development of fluorescent in situ hybridization chromosome-specific probes has allowed the use of new fetal tissue collection techniques, such as fetal cells in maternal blood and coelocentesis-both of which, with current techniques, cannot generate complete karyotypes. We evaluated chromosome—specific probes for additional potential limitations in the setting of a high-risk prenatal diagnosis center. Study Design: The last 24 months of fetal karyotypes from our prenatal cytogenetics laboratory were analyzed for those abnormalities that should be detectable by chromosome-specific probes and those that would likely be missed. Results: In 6006 karyotypes 207 (3.4%) abnormalities were found, of which 104 were common trisomies,12 triploidies, and 19 monosomies that would have been detected with current probe combinations (13, 18, 21, X, and Y) (135/207, 65.2%). Seventy-two abnormalities (35%) represented other trisomies (16/207, 7.7% for 9, 12, 15, 16) and rearrangements (inversions, translocation markers were 56/207, 27.1 %), which would have been missed. Conclusions: Use of current fluorescent in situ hybridization chromosome-specific probes protocols would have detected only 65% of chromosome abnormalities in our high-risk population. Incomplete ascertainment must be weighed against the cost and speed of fluorescent in situ hybridization chromosome-specific probes when comparing it with traditional karyotyping. Although this new technique may prove useful in low-risk screening programs (fetal cells in maternal blood), its current use in high-risk populations should be questioned until its sensitivity is expanded to identify more subtle and less common chromosomal abnormalities.
Fast and accurate numerical methods for solving elliptic difference equations defined on lattices

Techniques for rapidly computing approximate solutions to elliptic PDEs such as Laplace's equation are well established. For problems involving general domains, and operators with constant coefficients, a highly efficient approach is to rewrite the boundary value problem as a Boundary Integral Equation (BIE), and then solve the BIE using fast methods such as, e.g., the Fast Multipole Method (FMM). The current paper demonstrates that this procedure can be extended to elliptic difference equations defined on infinite lattices, or on finite lattice with boundary conditions of either Dirichlet or Neumann type. As a representative model problem, a lattice equivalent of Laplace's equation on a square lattice in two dimensions is considered: discrete analogs of BIEs are derived and fast solvers analogous to the FMM are constructed. Fast techniques are also constructed for problems involving lattices with inclusions and local deviations from perfect periodicity. The complexity of the methods described is O(N"b"o"u"n"d"a"r"y+N"s"o"u"r"c"e+N"i"n"c) where N"b"o"u"n"d"a"r"y is the number of nodes on the boundary of the domain, N"s"o"u"r"c"e is the number of nodes subjected to body loads, and N"i"n"c is the number of nodes that deviate from perfect periodicity. This estimate should be compared to the O(N"d"o"m"a"i"nlogN"d"o"m"a"i"n) estimate for FFT based methods, where N"d"o"m"a"i"n is the total number of nodes in the lattice (so that in two dimensions, N"b"o"u"n"d"a"r"y~N"d"o"m"a"i"n^1^/^2). Several numerical examples are presented.
An Open Trial of Sertraline for Cocaine Abuse

The authors assessed sertraline, a serotonin uptake inhibitor, in an open trial of 11 outpatient cocaine abusm. Cocaine craving decreased and psychological functioning improved. Five subjects abstained from use for 3 week. these results suggest sertmline's treatment efficacy for cocaine abuse and support a role for serotonin in this disorder.
Child abuse in an infant presenting as unexplained acute systemic hypertension

Hypertension in the infant is uncommon and is usually associated with renal vascular or parenchymal disease, coarctation or thrombosis of the aorta, or chronic lung disease. A 3-month-old infant who presented with unexplained acute systemic hypertension was subsequently discovered to have an undiagnosed femoral fracture secondary to child abuse. Undiagnosed fractures, which are often associated with child abuse, should be considered in the differential diagnosis of an infant presenting with unexplained systemic hypertension.
Turbulent flows through a disk-type prosthetic heart valve

A numerical model is developed to predict the complex velocity, shear and pressure fields in steady turbulent flow through a disk-type prosthetic heart valve in a constant diameter chamber. The governing Navier-Stokes equations are reduced to a set of simultaneous algebraic finite-difference equations which are solved by a fast-converging line-iterations technique. A two-parameter, two-equation model is employed to determine the turbulent viscosity. Numerical results are obtained for stream function, vorticity, and shear and normal stresses. The regions of very high shear and normal stresses in the fluid and at the walls are identified. The maximum value of the shear stress occurring near the upstream corner of the disk may cause hemolysis. The technique can be used together with in-vitro physcial experiments to evaluate existing or future prosthetic heart valve designs.
Measuring magnetic fields stronger than 100 teslas using miniature b-dot probes on COBRA

The MagLIF [1] concept relies on magnetic field compression to limit electron losses to the liner wall and reach fusion parameters. To measure magnetic field compression, B-dot probes could be used at the beginning of the implosions. However, this probe will fail as the magnetic field becomes large when the liner compresses. Our goal is to measure a 100T field created on two coaxial solenoids using the IMA 100ns rise time pulse power generator COBRA. The experimental setup is presented in another poster at this conference [2]. The miniature B-dot probes are fabricated using a 1mm in diameter coaxial cable. The center conductor is soldered to the outer jacket, forming a single turn loop of a quarter square millimeter area. An epoxy and kapton sleeve protects the central conductor from plasma generated in the load region of COBRA. The B-dot probe has a bandwidth greater than 1GHz. The magnetic field measurements were done at different locations on the plane of symmetry of the coil system to map the field topology between the two coils. Plasma shorting near the B-dot probe was avoided by connecting the two central conductors of the coils to the cathode of the machine, which is grounded. The magnetic field computed by an analytical code was compared to experimental measurements and excellent agreement was found.
Downstream Movement of Rainbow Trout Fry in a Tributary Sagehen Creek, under Permanent and Intermittent Flow

Abstract Rainbow trout fry spawned in an intermittent stream had a diel periodicity in downstream movement that was highly correlated with discharge. Shortly after fry emerged in mid-July 1973, Kiln Meadow Tributary of Sagehen Creek began to dry up and fry began to move downstream, primarily during the day. After rains, when the water level remained high (5 to 8 liters/s) without diel fluctuations, few fry were captured in the trap. In 1974 the tributary was permanent and fry exhibited a nocturnal downstream emigration. Many fry remained in the tributary where they were almost the only fish occupants.
Historical climate modelling predicts patterns of current biodiversity in the Brazilian Atlantic forest

Aim We aim to propose validated, spatially explicit hypotheses for the late Quaternary distribution of the Brazilian Atlantic forest, and thereby provide a framework for integrating analyses of species and genetic diversity in the region. Location The Atlantic forest, stretching along the Brazilian coast. Methods We model the spatial range of the forest under three climatic scenarios (current climate, 6000 and 21,000 years ago) with BIOCLIM and MAXENT. Historically stable areas or refugia are identified as the set of grid cells for which forest presence is inferred in all models and time projections. To validate inferred refugia, we test whether our models are matched by the current distribution of the forest and by fossil pollen data. We then investigate whether the location of inferred forest refugia is consistent with current patterns of species endemism and existing phylogeographical data. Results Forest models agree with pollen records and predict a large area of historical forest stability in the central corridor (Bahia), as well as a smaller refuge (Pernambuco) along the Brazilian coast, matching current centres of endemism in multiple taxa and mtDNA diversity patterns in a subset of the species examined. Less historical stability is predicted in coastal areas south of the Doce river, which agrees with most phylogeographical studies in that region. Yet some widely distributed taxa show high endemism in the southern Atlantic forest. This may be due to limitations of the modelling approach, differences in ecology and dispersal capability, historical processes not contemplated by the current study or inadequacy of the available test data sets. Main conclusions Palaeoclimatic models predict the presence of historical forest refugia in the Atlantic rain forest and suggest spatial variation in persistence of forests through the Pleistocene, predicting patterns of biodiversity in several local taxa. The results point to the need for further studies to document genetic and species endemism in the relatively poorly known and highly impacted areas of Atlantic rain forests of north-eastern Brazil.
Disambiguating clinical intentions: the ethics of palliative sedation.

It is often claimed that the intentions of physicians are multiple, ambiguous, and uncertain—at least with respect to end-of-life care. This claim provides support for the conclusion that the principle of double effect is of little or no value as a guide to end-of-life pain management. This paper critically discusses this claim. It argues that proponents of the claim fail to distinguish two different senses of "intention, " and that, as a result, they are led to exaggerate the extent to which clinical intentions in end-of-life contexts are ambiguous and uncertain. It argues further that physicians, like others who make life and death decisions, have a duty to get clear on what their intentions are. Finally, it argues that even if the principle of double effect should be rejected, clinical intentions remain ethically significant because they condition the meaning of extraordinary clinical interventions, such as that ofpalliative sedation.
Fluorometric quantification of polyphosphate in environmental plankton samples: extraction protocols, matrix effects, and nucleic acid interference

Polyphosphate (polyP) is a ubiquitous biochemical with many cellular functions and comprises an important environmental phosphorus pool. However, methodological challenges have hampered routine quantification of polyP in environmental samples. We tested 15 protocols to extract inorganic polyphosphate from natural marine samples and cultured cyanobacteria for fluorometric quantification with 4′,6-diamidino-2-phenylindole (DAPI) without prior purification. A combination of brief boiling and digestion with proteinase K was superior to all other protocols, including other enzymatic digestions and neutral or alkaline leaches. However, three successive extractions were required to extract all polyP. Standard addition revealed matrix effects that differed between sample types, causing polyP to be over- or underestimated by up to 50% in the samples tested here. Although previous studies judged that the presence of DNA would not complicate fluorometric quantification of polyP with DAPI, we show that RNA can cause significant interference at the wavelengths used to measure polyP. Importantly, treating samples with DNase and RNase before proteinase K digestion reduced fluorescence by up to 57%. We measured particulate polyP along a North Pacific coastal-to-open ocean transect and show that particulate polyP concentrations increased toward the open ocean. While our final method is optimized for marine particulate matter, different environmental sample types may need to be assessed for matrix effects, extraction efficiency, and nucleic acid interference.