cssi/SciSciGPT-SciSciNet huggingface dataset:
Twin pregnancies conceived by assisted reproductive techniques : Maternal and neonatal outcomes

Objective: To determine whether twin pregnancies conceived by assisted reproductive techniques are at increased risk for obstetric complications or perinatal morbidity. Methods: A computerized perinatal data base was reviewed for all twin pregnancies managed by private obstetricians and delivered between 1990 and 1995. The obstetric and neonatal outcomes of those conceived following in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT) were compared to the outcomes of those conceived spontaneously. Results: There were 105 twin deliveries following IVF or GIFT and 279 following natural fertilization. Discordant birth weight and low birth weight occurred more frequently in pregnancies conceived by IVF or GIFT (adjusted odds ratio [OR] 2.11, 95% confidence interval [CI] 1.14, 3.91; OR 1.65, 95% CI 0.98, 2.79, respectively). Elective cesarean delivery was more frequent in twin pregnancies conceived after IVF GIFT (relative risk [RR] 4.02, 95% CI 1.28, 12.6). There were no statistically significant differences in the frequency of antepartum or intrapartum complications, preterm delivery, or mean gestational age at delivery. There was no statistically significant increase in the frequency of neonatal complications among infants born after IVF GIFT. Conclusion: Although twin pregnancies following IVF or GIFT are more likely to result in discordant birth weight infants, the perinatal outcome is comparable to that of spontaneously conceived twin pregnancies.
Backward Error Analysis for Linear Systems Associated with Inverses of H-Matrices,

In this paper, bounds on the growth factors resulting from Gaussian elimination applied to inverses ofH-matrices are developed and investigated. These bounds are then used in the error analysis for solving linear systemsAx =b whose coefficient matricesA are of this type. For each such system our results show that the Gaussian elimination without pivoting can proceed safely provided that the elements of the inverse of a certainM-matrix (associated with the coefficient matrixA) are not excessively large. We exhibit a particularly satisfactory situation for the special case whenA itself is an inverse of anM-matrix. Part of the first section of this paper is devoted to a discussion on some results of de Boor and Pinkus for the stability of triangular factorizations of systemsAx =b, whereA is a nonsingular totally nonnegative matrix, and to the explanation of why the analysis of de Boor and Pinkus is not applicable to the case when the coefficient matrixA is an inverse of anM-matrix.
Temperature control of multizone indoor spaces based on forecast and actual loads

Abstract This paper presents the design of a multivariable controller for zone temperature control. A two-zone building with a fan-coil heating system is considered and a multi-input controller is designed. The controller tracks the reference trajectories which are generated based on forecasted outdoor temperature and at the same time regulates the zone temperatures in response to the actual variations in outdoor temperatures. Results showing the closed-loop responses of the system under realistic operating conditions are given.
Creole Studies and Sociolinguistics

Depuis les annees soixante la linguistique creole est devenue un champ de recherche a part entiere, apportant des contributions dans de nombreux autres domaines de la linguistique, et principalement en sociolinguistique. La relation entre etudes creoles et sociolinguistique a traditionnellement ete la plus forte dans deux aires de recherche particulieres : l'histoire sociale et la sociolinguistique appliquee
Diamond fraise technique for dermal grafts in temporomandibular disk reconstruction

Dermal grafts have been described for a variety of applications, including preprosthetic surgery, reconstructive surgery, and temporomandibular joint surgery. Several reports have described the procedural techniques for acquiring a dermal graft. The surgical technique for harvesting a dermal graft with the use of the dermabrading diamond fraise bur is described. The use of the diamond fraise bur offers many unique surgical advantages: it allows minimal damage to the dermal layer; the healing surface is smooth, cosmetic, homogenous, and devoid of scratches or debris; an adequate graft of uniform thickness is obtained; the technique allows access to a variety of donor sites; and minimal patient postoperative donor site morbidity. The use of this technique provides a simple, cosmetic approach to obtaining an adequate dermal graft for temporomandibular joint reconstructive procedures, while minimizing the potential complications associated with other commonly used techniques.
The Legacy of the U. S. Public Health Service Study of Untreated Syphilis in African American Men at Tuskegee on the Affordable Care Act and Health Care Reform Fifteen Years after President Clinton's Apology

This special issue addresses the legacy of the U.S. Public Health Service Syphilis Study on health reform, particularly the Affordable Care Act. This article offers readers a guide to the themes that emerge in this issue. These themes include individual consent interrelated to consequences in populations issues, need for better government oversight in research and health care, and the need for overhauling our bioethics training to develop a population-level, culturally driven approach to research bioethics. We hope the guidance offered in this issue will help shape a new framework to bioethics that can be integrated into the foundation of health care reform.
Patriarchy in Colonial New England

This article explores the social relations of production within the rural household of colonial New England. It draws upon a review of the litera ture as well as primary research in Western Massachusetts to describe important aspects of patriarchal domination of sons and the extent and significance of the sexual division of labor. Two significant theoretical issues are emphasized: 1) There are important interconnections between control over children and control over women which have important implications for understanding the impact of the growth of capitalism on the family and 2) The fact that women in colonial New England played an important role in production did not ensure them any objective power within the household.
To boldly go ...

Uranus the Planet, Rings and Satellites. By Ellis D. Miner. Horwood: 1990. Pp. 334. £35.50.
Using a Local Greenway to Study the River Environment and Urban Landscape

Abstract Greenways are prominent features of many urban landscapes and synthesize several geographic topics: human–environment interactions, urban ecosystems, and the promotion of sustainability within riverine corridors. Greenways are easily accessible and provide an opportunity for students at various grade levels to study interactions across physical and human systems. Students can gain an appreciation of the natural and cultural resources located in a local river environment while building skills linked to the National Geography Standards. Greenway-related activities can be designed so that students practice the acquisition, interpretation, and integration of geographic information obtained from a variety of sources and methods.
The early stage of fatigue crack propagation in al 2048

Microcracks which develop at the surface of Al 2048 subjected to fully reversed fatigue loading are found to be partially open at zero load. The magnitude of such residual crack openings measured at the test specimen surface is determined as a function of the crack length and the relative humidity in which the specimens were fatigued. For a fixed crack length the residual crack openings are found to be largest if the relative humidity is low or if the crack path is particularly irregular. The present interpretation of the phenomenon is that the residual crack openings are indirectly related to the crack closure load associated with the microcracks.
Porosity/formation‐factor relationships for high‐porosity siliciclastic sediments from Amazon Fan

The electrical resistivity of siliciclastic rocks is a function both of pore-fluid resistivity and of formation factor (FF), an intrinsic rock property. For low-porosity rocks, FF depends on clay conduction and porosity. In contrast, we find that FF of high-porosity sediments (fractional porosities of 0.3–0.6) from Amazon Fan is controlled primarily by porosity and pore geometry; clay conduction is a minor effect. Porosity vs. formation factor (FF) plots for Amazon Fan well logs demonstrate two distinct trends which are dependent on the amount of shale present. Muds, with more than about 0.4 shale fraction, follow a trend that increases to much higher FF as porosity decreases, compared to sands and slightly muddy sands. This separation is of opposite sign to the separation between low-porosity sandstones and shales attributable to clay conduction. We conclude that in high-porosity muds, presence of clays reduces formation conductivity by increasing the tortuosity of pores.
Real-Time Volume Rendering of Four Channel Data Sets

We present a novel method to encode four data channels in a volumetric data set, and render it at interactive frame rates with maximum intensity projection (MIP) using textured polygons. The first three channels are stored in the volume textures red, green, and blue components. The fourth channel is stored in the alpha channel. To achieve real-time rendering speed we are using a pixel shader.
Consumer cluster analysis and demand for blueberry jam attributes.

Using a recent in-store stated choice survey, this study examines consumer preference and willingness to pay for blueberry jam with quality attributes not commonly seen on the market. A cluster analysis is first adopted to classify consumers into different groups based on a large number of consumer characteristic variables. A spilt sample analysis is conducted under each cluster and results indicate that consumers behave differently in separate clusters and the derived economic values associated with each attribute also depend on cluster membership.
Catabolic and genetic microbial indices, and levels of nitrate, ammonium and organic carbon in soil from the black locust ( Robinia pseudo-acacia) and tulip poplar ( Liriodendron tulipifera) trees in a Pennsylvania forest

Soil samples were collected from the upper soil horizon within 4 m of black locust ( Robinia pseudo-acacia) and tulip poplar trees ( Liriodendron tulipifera) from the same mixed forest in south-central Pennsylvania. The soil samples were analyzed for organic C levels, pH, NO3-, NH4+, catabolic diversity (Shannon diversity index; catabolic H), catabolic evenness (Simpson-Yule index; catabolic E), genetic H, and genetic E. The catabolic H and genetic H of microbes in these soils were found to correlate well with the levels of mineralized N, organic C, and pH. Significant variations in these parameters were found between the soils from near black locust and tulip poplar trees. Conditions in the soil near the black locust trees were more favorable to nitrification as indicated by the elevated pH, organic C, NO3-, and total mineral N levels, along with lower NH4+ levels. The microbial genetic H and E were greater and the catabolic H and E were lower in the black locust soils than in the tulip poplar soils. This suggests that a more specialized environment exists in the soil near the black locust trees which selects for enhanced nitrification and the use of fewer, but preferred catabolic pathways by a more genetically diverse group of microbes that grow to a greater biomass. Conversely, the soils from near the tulip poplar trees are such that they do not select for some dominant catabolic pathways, rather they allow for the use of a greater variety of catabolic pathways by a less diverse microbial population, which appear to grow to a lower biomass. We believe that the combined application of the microbial genetic and catabolic diversity analyses, microbial biomass estimates, and traditional physico-chemical characteristics in soil studies provides information not easily available that can be useful during assessment of soil processes in different terrestrial habitats.
The Laplace relation and the masses of Uranus' satellites

It is noted that the mean motions of Uranus' satellites Miranda, Ariel, and Umbriel exhibit nearly the same commensurability as that observed among the three inner Galilean satellites of Jupiter, which is referred to as the Laplace relation. The theory of the Laplace relation among the Uranian satellites is completed by generating terms due to the first-order portions of the disturbing functions, using a generalization of Souillart's approach for the Galilean satellites. The theory is compared with past observations of Miranda's mean motion to obtain an upper limit on the product of the masses of Ariel and Umbriel. This mass limit is examined in terms of implied density and albedo constraints for comparison with the bulk properties of other solar-system bodies. The results suggest that if Ariel and Umbriel both have the same geometric albedo and density, then Ariel's radius would have to be less than about 1200 km and Umbriel's, less than about 800 km.
Short-range structure of invert glasses along the pseudo-binary join MgSiO3-Mg2SiO4: results from 29Si and 25Mg MAS NMR spectroscopy.

The short-range structure of “invert” glasses along the pseudobinary join MgSiO3−Mg2SiO4 has been studied using 29Si and 25Mg MAS NMR spectroscopy. The results indicate a progressive compositional evolution in Q speciation that approximately follows a statistical distribution. The Mg2SiO4 glass shows an abrupt deviation from this trend with the presence of nearly 40% of the Si atoms as (Si2O7)6− dimers, i.e., Q1 species. Mg2+ ions are present in predominantly octahedral coordination in all glasses. When taken together, these results indicate that glasses with MgO contents between 50 and 60 mol % are characterized by a structure consisting primarily of at least three types of Q species and MgO6 octahedra. On the other hand, the structure of glasses with >60 mol % MgO appears to consist of Q0 and Q1 species with structural connectivity being primarily provided by the MgO6 octahedra. The possible consequences of such compositional evolution of structure on the ability of glass formation in this system are di...
Body size and sexual size dimorphism in primates: influence of climate and net primary productivity

Understanding the evolution of body size and sexual size dimorphism has been a longstanding goal in evolutionary biology. Previous work has shown that environmental stress can constrain male-biased sexual size dimorphism at the population level, but we know little about how this might translate to geographical patterns of body size and sexual size dimorphism at the species level. Environmental constraints due to a highly seasonal, resource-poor and/or variable environment have often been cited to explain the unusual lack of sexual size dimorphism among Madagascar’s diverse and numerous primate taxa; however, empirical tests of this hypothesis are lacking. Using a phylogenetic approach and a geographical information system platform, we explored the role of seasonality, interannual variability and annual measures of temperature and rainfall, and net primary productivity on patterns of body size and sexual size dimorphism across 130 species of primates. Phylogenetically controlled comparisons showed no support for a role of environmental constraints in moderating sexual size dimorphism at the interspecific level, despite significant associations of environmental variables with body mass. Results suggest that the focus of discussions that have dominated in the last two decades regarding the role of environmental constraints in driving patterns of monomorphism of Madagascar’s lemurs should be reconsidered; however, the conundrum remains.
Binding of Substrates to the Central Pore of the Vps4 ATPase Is Autoinhibited by the Microtubule Interacting and Trafficking (MIT) Domain and Activated by MIT Interacting Motifs (MIMs)

The endosomal sorting complexes required for transport (ESCRT) pathway drives reverse topology membrane fission events within multiple cellular pathways, including cytokinesis, multivesicular body biogenesis, repair of the plasma membrane, nuclear membrane vesicle formation, and HIV budding. The AAA ATPase Vps4 is recruited to membrane necks shortly before fission, where it catalyzes disassembly of the ESCRT-III lattice. The N-terminal Vps4 microtubule-interacting and trafficking (MIT) domains initially bind the C-terminal MIT-interacting motifs (MIMs) of ESCRT-III subunits, but it is unclear how the enzyme then remodels these substrates in response to ATP hydrolysis. Here, we report quantitative binding studies that demonstrate that residues from helix 5 of the Vps2p subunit of ESCRT-III bind to the central pore of an asymmetric Vps4p hexamer in a manner that is dependent upon the presence of flexible nucleotide analogs that can mimic multiple states in the ATP hydrolysis cycle. We also find that substrate engagement is autoinhibited by the Vps4p MIT domain and that this inhibition is relieved by binding of either Type 1 or Type 2 MIM elements, which bind the Vps4p MIT domain through different interfaces. These observations support the model that Vps4 substrates are initially recruited by an MIM-MIT interaction that activates the Vps4 central pore to engage substrates and generate force, thereby triggering ESCRT-III disassembly.
SECONDARY AEROSOL: PRODUCTION MECHANISMS OF SULFATE COMPOUNDS IN THE ATMOSPHERE

Current concepts concerning the homogeneous and heterogeneous processes that contribute to particle production in the atmosphere are examined, with particular attention given to the mechanisms of formation of sulfate compounds. SO/sub 2/ oxidation by the reactive radicals OH, HO/sub 2/, and CH/sub 3/O can account for the observed production rate of sulfate compounds (1-5% per hour) in the photochemically active urban atmosphere. Liquid-phase oxidation of SO/sub 2/ by O/sub 2/ in the presence of catalysts and by dissolved O/sub 3/ (and possibly H/sub 2/O/sub 2/) appears to be important in less photochemically active atmospheres. The factors that determine sulfate production rate by liquid phase processes are investigated, including cloud type, O/sub 3/ concentration, droplet pH, catalyst concentration, and atmospheric liquid water content.
Segmentation, reconstruction, and analysis of blood thrombus formation in 3D 2-photonmicroscopy images

We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots) in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape) algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII) and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.
Oregon State University sea gravity investigations

In 1963 Oregon State University obtained over 4,000 miles of continuous gravity measurements at sea from the Oregon coast westward to beyond the seaward extension of the San Andreas fault and from Point Mendocino, California, to Astoria Canyon, Oregon. Measurements were made on the U. S. Coast Guard cutter Yocona, a 213-foot, 1900-ton ship. The measurements include 7 lines from the coast westward for a distance of 100–300 miles, 15 profiles across the San Andreas fault extension, and 1 profile across the Mendocino escarpment. Free air anomalies for these measurements have been calculated, and a free air anomaly map has been contoured. The reliability and accuracy of LaCoste-Romberg gravity meter S-9 was checked against a gravity range which had been previously obtained from an underwater gravity meter off Newport, Oregon. Surface-ship gravity readings were found to be accurate within 6 mgal, even at Browne corrections up to 450 mgal, where the errors included navigational effects. Comparable errors were obtained at intersections of profiles in the larger gravity program off Oregon. Results of the reliability determinations of meter S-9 are being prepared for publication, as based on measurements over the Newport gravity range, on measurements past an offshore petroleum platform in the Gulf of Mexico, and from intersections of numerous gravity profiles in the Gulf of Mexico and off the coast of Oregon.
Novel liquid blanket configurations and their hydrodynamic analyses for innovative confinement concepts

Abstract Hydrodynamics analyses as a part of the APEX (advanced power extraction) study demonstrates the potential application of applying swirling thick liquid walls to innovative confinement concepts such as field reversed configuration (FRC), spherical torus (ST) and heavy-ion fusion (HIF). This paper addresses the design and the hydrodynamic aspects of fusion relevant swirling flow including 3-D velocity distribution, variations of the flow height in axial and azimuthal directions and hydrodynamic flow stability. Numerical hydrodynamic analyses using a 3-D code with Flibe as the working fluid, shows that a thick liquid first-wall/blanket (>0.6 m) can be maintained in a circular vacuum chamber of 2 m radius by injecting the liquid layer from one side through a swirl flow generating inlet with axial (7 m/s) and azimuthal (10 m/s) velocity components. Parametric computational study indicated that the liquid layer thickness in axial and azimuthal directions is strongly dependent on the inlet axial, azimuthal velocity values and gravitational acceleration. It also shows that a uniform liquid layer thickness can be maintained for axial and azimuthal inlet velocities of 11 and 13 m/s in a cylindrical chamber with a 2 m radius and 12 m length. The swirling liquid wall idea is applied successfully to ST and HIF configurations. A 2D linear stability analysis using potential flow theory (Reynolds number is ∼106 for liquid wall thickness of ∼0.5 m) of the swirling flow in the azimuthal flow direction suggested that mean flow is stable when the surface tension, gravitational acceleration, and the centrifugal force effects are considered.
Quantum dot intermixing with thermal and laser annealing

Photoluminescence (PL) was used to investigate the interdifflision of self-assembled InAs/GaAs quantum dots (QDs) treated by rapid thermal annealing (RTA) and laser annealing. The observation ofintense and sharp shell structures confirmed that the QDs retained their zero-dimensional density of states. In addition, three main effects of alloy intermixing were demonstrated in QDs having different intersublevel spacings. The emission has been strongly blue-shifted, up to -200 meV for RTA samples and 298 meV for the laser annealed ones. The intersublevel spacing was tuned between 6O meV to '-'25 meV in the RTA case, but down to -12 meV in the case of laser-induced intermixing. Finally the inhomogeneous broadening linearly decreased from a FWHM of-46 meV down to smaller than 15 meV for RTA and 8 meV in the most extreme case of laser annealing. For samples annealed at the highest temperatures, the most energetic shells of QDs become unbound. Across varying samples, the result ofthe intermixing was to increase the uniformity of their PL spectra. A onedimensional model of Fickian diffusion for the growth direction was used to model their PL emission. Rapid thermal annealing and laser annealing provide two additional ways of manipulating the energy levels of self-assembled QD ensembles by tuning the intersublevel energy-spacing and the number ofconfined states.
Connexin 43 deficiency desensitizes bone to the effects of mechanical unloading through modulation of both arms of bone remodeling

Connexin 43 (Cx43) is a gap junction protein that plays an integral role in the skeletal response to mechanical loading and unloading. In a previous study, we demonstrated preservation of trabecular bone mass and cortical bone formation rate in mice with an osteoblast/osteocyte-selective deficiency of Cx43 (cKO) following mechanical unloading via hindlimb suspension (HLS). In the present study, we sought to define the potential mechanisms underlying this response. Following three weeks of HLS, mRNA levels of Sost were significantly greater in wild-type (WT)-Suspended mice vs. WT-Control, while there was no difference between cKO control and cKO-Suspended. Unloading-induced decreases in P1NP, a serum marker of bone formation, were also attenuated in cKO-Suspended. The proportion of sclerostin-positive osteocytes was significantly lower in cKO-Control vs. WT-Control (-72%, p<0.05), a difference accounted for by the presence of numerous empty lacunae in the cortical bone of cKO vs. WT. Abundant TUNEL staining was present throughout the cortical bone of the tibia and femur, suggesting an apoptotic process. There was no difference in empty lacunae in the trabecular bone of the tibia or femur. Trabecular and cortical osteoclast indices were lower in cKO-Suspended vs. WT-Suspended; however, mRNA levels of the gene encoding RANKL increased similarly in both genotypes. Connexin 43 deficient mice experience attenuated sclerostin-mediated suppression of cortical bone formation and lower cortical osteoclast activity during unloading. Preservation of trabecular bone mass and attenuated osteoclast activity during unloading, despite an apparent lack of effect on osteocyte viability at this site, suggests that an additional mechanism independent of osteocyte apoptosis may also be important. These findings indicate that Cx43 is able to modulate both arms of bone remodeling during unloading.
Opting Out or Denying Discrimination? How the Framework of Free Choice in American Society Influences Perceptions of Gender Inequality

American women still confront workplace barriers (e.g., bias against mothers, inflexible policies) that hinder their advancement at the upper levels of organizations. However, most Americans fail to recognize that such gender barriers still exist. Focusing on mothers who have left the workforce, we propose that the prevalent American assumption that actions are a product of choice conceals workplace barriers by communicating that opportunities are equal and that behavior is free from contextual influence. Study 1 reveals that stay-at-home mothers who view their own workplace departure as an individual choice experience greater well-being but less often recognize workplace barriers and discrimination as a source of inequality than do mothers who do not view their workplace departure as an individual choice. Study 2 shows that merely exposing participants to a message that frames actions in terms of individual choice increases participants' belief that society provides equal opportunities and that gender discrimination no longer exists. By concealing the barriers that women still face in the workplace, this choice framework may hinder women's long-term advancement in society.
Effect of age and coronary heart disease on the circulatory responses to graded lower body negative pressure

Previous reports have demonstrated that haemodynamic responses to various autonomic stresses such as head-up tilt, Valsalva's manoeuvre, face immersion, cold pressor, and static exercise are altered with increasing age and cardiac disease. In the present investigation, we compared the responses of 20 to 27 year old and 50 to 59 year old healthy men and 50 to 59 year old ambulatory coronary heart disease patients to graded lower body negative pressure (LBNP). Noninvasive methods including transthoracic impedance cardiography and venous occlusion plethysmography were used to monitor changes in stroke index, thoracic blood volume and vascular resistance. The tachycardia and stroke index decline of the older men and cardiac patients at higher levels of LBNP were similar but less than those of the younger men; we also noted greater increases in forearm and total peripheral resistance during LBNP in the two older groups than in the younger group. However, the decreases in thoracic blood volume were less in the two older groups at the higher levels of LBNP indicating that older subjects had been subjected to a lesser stress. These differences in thoracic blood volume displacement may be due to a decreased peripheral venous compliance in older subjects. When we compared responses to similar decreases in thoracic blood volume, the heart rate and stroke index changes were similar in the three groups but the exaggerated forearm vascular resistance and total peripheral resistance index increases in the older groups persisted. Our data suggest: (1) the decreased haemodynamic response to postural stress previously reported in older subjects and cardiac patients is due at least in part to a lesser peripheral sequestration of blood in the older individuals; (2) the lesser heart rate and stroke index responses in coronary heart disease patients to diminished preload stress may be due primarily to normal aging; and (3) the greater increases in peripheral vascular resistance in the two older groups during LBNP may be a function of the higher baseline resistance levels in these older subjects.
Molecular imaging in small animals--roles for micro-CT.

X-ray micro-CT is currently used primarily to generate 3D images of micro-architecture (and the function that can be deduced from it) and the regional distribution of administered radiopaque indicators, within intact rodent organs or biopsies from large animals and humans. Current use of X-ray micro-CT can be extended in three ways to increase the quantitative imaging of molecular transport and accumulation within such specimens. (1) By use of heavy elements, other than the usual iodine, attached to molecules of interest or to surrogates for those molecules. The accumulation of the indicator in the physiological compartments, and the transport to and from such compartments, can be quantitated from the imaged spatial distribution of these contrast agents. (2) The high spatial resolution of conventional X-ray attenuation-based CT images can be used to improve the quantitative nature of radionuclide-based tomographic images (SPECT & PET) by providing correction for attenuation of the emitted gamma rays and the accurate delineation of physiological spaces known to selectively accumulate those indicators. Similarly, other imaging modalities which also localize functions in 2D images (such as histological sections subsequently obtained from the same specimen), can provide a synergistic combination with CT-based 3D microstructure. (3) By increasing the sensitivity and specificity of X-ray CT image contrast by use of methods such as: K-edge subtraction imaging, X-ray fluorescence imaging, imaging of the various types of scattered X-ray and the consequences of the change in the speed of X-rays through different tissues, such as refraction and phase shift. These other methods of X-ray imaging can increase contrast by more than an order of magnitude over that due to conventionally-used attenuation of X-ray. To fully exploit their potentials, much development of radiopaque indicators, scanner hardware and image reconstruction and analysis software will be needed.
Class A Carbapenemase FPH-1 from Francisella philomiragia

ABSTRACT FPH-1 is a new class A carbapenemase from Francisella philomiragia. It produces high-level resistance to penicillins and the narrow-spectrum cephalosporin cephalothin and hydrolyzes these β-lactam antibiotics with catalytic efficiencies of 10 6 to 10 7 M −1 s −1 . When expressed in Escherichia coli, the enzyme confers resistance to clavulanic acid, tazobactam, and sulbactam and has K i values of 7.5, 4, and 220 μM, respectively, against these inhibitors. FPH-1 increases the MIC of the monobactam aztreonam 256-fold and the MIC of the broad-spectrum cephalosporin ceftazidime 128-fold, while the MIC of cefoxitin remains unchanged. MICs of the carbapenem antibiotics imipenem, meropenem, doripenem, and ertapenem are elevated 8-, 8-, 16-, and 64-fold, respectively, against an E. coli JM83 strain producing the FPH-1 carbapenemase. The catalytic efficiencies of the enzyme against carbapenems are in the range of 10 4 to 10 5 M −1 s −1 . FPH-1 is 77% identical to the FTU-1 β-lactamase from Francisella tularensis and has low amino acid sequence identity with other class A β-lactamases. Together with FTU-1, FPH-1 constitutes a new branch of the prolific and ever-expanding class A β-lactamase tree.
Short Stature and Dysmorphism in the Child and Adolescent Female Diagnostic Dilemmas

The clinician often encounters girls with varying combinations of short stature and subtle dysmorphic features that are compatible with either Turner or Noonan syndrome. A classic case of either syndrome with extensive unmistakable traits is the exception rather than the rule. Six cases are presented to help describe some of the difficulties in differential diagnosis and provide strategies to avert them.
Controlling biological systems: the lactose regulation system of Escherichia coli

In this paper we present a comprehensive framework for abstraction and controller design for a biological system. The first half of the paper concerns modeling and model abstraction of the system. Most models in systems biology are deterministic models with ordinary differential equations in the concentration variables. We present a stochastic hybrid model of the lactose regulation system of E. coli bacteria that capture important phenomena which cannot be described by continuous deterministic models. We then show that the resulting stochastic hybrid model can be abstracted into a much simpler model, a two-state continuous time Markov chain. The second half of the paper discusses controller design for a specific architecture. The architecture consists of measurement of a global quantity in a colony of bacteria as an output feedback, and manipulation of global environmental variables as control actuation. We show that controller design can be performed on the abstracted (Markov chain) model and implementation on the real model yields the desired result.
Science education as a pathway to teaching language literacy: a critical book review

In this paper, I present a critical review of the recent book, Science Education as a Pathway to Teaching Language Literacy, edited by Alberto J. Rodriguez. This volume is a timely collection of essays in which the authors bring to attention both the successes and challenges of integrating science instruction with literacy instruction (and vice versa). Although several themes in the book merit further attention, a central unifying issue throughout all of the chapters is the task of designing instruction which (1) gives students access to the dominant Discourses in science and literacy, (2) builds on students’ lived experiences, and (3) connects new material to socially and culturally relevant contexts in both science and literacy instruction—all within the high stakes testing realities of teachers and students in public schools. In this review, I illustrate how the authors of these essays effectively address this formidable challenge through research that ‘ascends to the concrete’. I also discuss where we could build on the work of the authors to integrate literacy and science instruction with the purpose of ‘humanizing and democratizing’ science education in K-12 classrooms.
Numerical integration in statistical decision-theoretic methods for robust design optimization

The Bayes principle from statistical decision theory provides a conceptual framework for quantifying uncertainties that arise in robust design optimization. The difficulty with exploiting this framework is computational, as it leads to objective and constraint functions that must be evaluated by numerical integration. Using a prototypical robust design optimization problem, this study explores the computational cost of multidimensional integration (computing expectation) and its interplay with optimization algorithms. It concludes that straightforward application of standard off-the-shelf optimization software to robust design is prohibitively expensive, necessitating adaptive strategies and the use of surrogates.
Evaluation of platelet deposition and neointimal hyperplasia of heparin-coated small-caliber ePTFE grafts in a canine femoral artery bypass model.

Abstract Introduction Bypass graft failure due to acute thrombosis and intimal hyperplasia remains a major challenge in small-diameter vascular prosthetic graft reconstruction. Heparin has been shown to prevent thrombus formation and inhibit intimal antithrombotic in animal studies. In this study, we evaluated the effect of small-caliber heparin-coated expanded polytetrafluoroethylene (ePTFE) grafts on platelet deposition and intimal hyperplasia in a canine model of femoral artery bypass grafting. Methods Nine adult greyhound dogs underwent placement of bilateral femorofemoral artery bypass grafts with ePTFE grafts (4 mm diameter and 7 cm long). In each animal, a heparin-coated ePTFE graft was placed on one side while a noncoated graft was placed on the contralateral side which served as the control. Platelet deposition was measured by autologous 111indium-labeling and scintillation camera imaging analysis in 24 h. The graft patency was assessed at 4 weeks following the bypass. The effect of intimal hyperplasia was assessed with histological and morphometric analysis. Results Platelet deposition on the heparin-coated grafts at 24 h was significantly reduced by 72% as compared to controls (P = 0.001). The patency rate was 44% in control grafts and 89% in heparin-coated grafts. There was a significant reduction of graft intimal hyperplasia at both proximal (0.38 ± 0.21 mm2) and distal (0.19 ± 0.06 mm2) anastomoses in the heparin-coated grafts as compared with proximal (1.01 ± 0.28 mm2) and distal (0.42 ± 0.01 mm2) anastomoses in the untreated control grafts, respectively (P Conclusions These data demonstrate that heparin coating of ePTFE significantly reduced early platelet deposition and inhibited anastomotic neointimal hyperplasia. Moreover, small-caliber heparin-coated ePTFE graft significantly increased graft patency in a canine femoral artery bypass model. This may represent a promising treatment strategy for improving the clinical performance of small-caliber prosthetic vascular grafts.
An Age-Dependent Physiologically Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Insecticide Chlorpyrifos in the Preweanling Rat

Juvenile rats are more susceptible than adults to the acute toxicity of organophosphorus insecticides like chlorpyrifos (CPF). Age- and dose-dependent differences in metabolism may be responsible. Of importance are CYP450 activation and detoxification of CPF to chlorpyrifos-oxon (CPF-oxon) and trichloropyridinol (TCP), as well as B-esterase (B-est) and PON-1 (A-esterase) detoxification of CPF-oxon to TCP. In the current study, a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model incorporating age-dependent changes in CYP450, PON-1, and tissue B-est levels for rats was developed. In this model, age was used as a dependent function to estimate body weight which was then used to allometrically scale both metabolism and tissue cholinesterase (ChE) levels. In addition, age-dependent changes in brain, liver, and fat volumes and brain blood flow were obtained from the literature and used in the simulations. Model simulations suggest that preweanling rats are particularly sensitive to CPF toxicity, with levels of CPF-oxon in blood and brain disproportionately increasing, relative to the response in adult rats. This age-dependent nonlinear increase in CPF-oxon concentration may potentially result from both the depletion of nontarget B-est and a lower PON-1 metabolic capacity in younger animals. The PBPK/PD model behaves consistently with the general understanding of CPF toxicity, pharmacokinetics, and tissue ChE inhibition in neonatal and adult rats. Hence, this model represents an important starting point for developing a computational model to assess the neurotoxic potential of environmentally relevant organophosphate exposures in infants and children.
Porous structure and fluid partitioning in polyethylene cores from 3D X-ray microtomographic imaging.

Using oil–wet polyethylene core models, we present the development of robust throat finding techniques for the extraction, from X-ray microtomographic images, of a pore network description of porous media having porosity up to 50%. Measurements of volume, surface area, shape factor, and principal diameters are extracted for pores and area, shape factor and principal diameters for throats. We also present results on the partitioning of wetting and non-wetting phases in the pore space at fixed volume increments of the injected fluid during a complete cycle of drainage and imbibition. We compare these results with fixed fractional flow injection, where wetting and non-wetting phase are simultaneously injected at fixed volume ratio. Finally we demonstrate the ability to differentiate three fluid phases (oil, water, air) in the pore space.
Civilian, ROTC, and Military Academy Undergraduate Attitudes toward Homosexuals in the U.S. Military A Research Note

The authors investigate a gap in attitudes toward homosexuals in the U.S. military among a select group of people—American civilian undergraduates, Reserve Officer Training Corp (ROTC) cadets, and ...
Definitions and analysis of DNA Holliday junction geometry

A number of single-crystal structures have now been solved of the four-stranded antiparallel stacked-X form of the Holliday junction. These structures demonstrate how base sequence, substituents, and drug and ion interactions affect the general conformation of this recombination intermediate. The geometry of junctions had previously been described in terms of a specific set of parameters that include: (i) the angle relating the ends of DNA duplexes arms of the junction (interduplex angle); (ii) the relative rotation of the duplexes about the helix axes of the stacked duplex arms (J(roll)); and (iii) the translation of the duplexes along these helix axes (J(slide)). Here, we present a consistent set of definitions and methods to accurately calculate each of these parameters based on the helical features of the stacked duplex arms in the single-crystal structures of the stacked-X junction, and demonstrate how each of these parameters contributes to an overall conformational feature of the structure. We show that the values for these parameters derived from global rather than local helical axes through the stacked bases of the duplex arms are the most representative of the stacked-X junction conformation. In addition, a very specific parameter (J(twist)) is introduced which relates the relative orientation of the stacked duplex arms across the junction which, unlike the interduplex angle, is length independent. The results from this study provide a general means to relate the geometric features seen in the crystal structures to those determined in solution.
Conflicts of Interest: Science, Money, and Health

Impressive advances in science and medicine occurred during the 20th century. During the 100-year span from 1900-2000 life expectancy for men increased from 47 to 74 years. Scientific discoveries such as the vaccines for polio and the development of effective and safe antibiotics have markedly improved the general level of health on our planet. Identification of the relationship between high blood pressure cholesterol level and atherosclerosis led to the development of drugs and interventions that have helped to control each of these entities and thereby improve the morbidity and mortality associated with atherosclerotic vascular disease. Laboratory and clinical investigations continue to be essential components in a process that has already led to markedly better health for many Americans. (excerpt)
Psychoanalysis, Narrative Psychology, and the Meaning of “Science”

Drawing especially on an important essay by Martin Heidegger, entitled “Science and Reflection” (1977), this article argues that case reports can, and should, be written for scientific use. This issue was brought to the fore early on in Freud's career, upon his realization that his own case studies read like short stories and that they lacked “the serious stamp of science.” Consoled by the fact that “the nature of the subject” was responsible for this and that more traditional scientific procedures “[led] nowhere,” he would continue with such writing and, through it, continue to fashion and refashion psychoanalytic theory. Freud, therefore, arrived at something of a paradox: even though by traditional standards—including, on some level, his own—his case studies seemed questionable in regard to their scientific utility, it was precisely these studies that yielded the desired insight. Knowingly or not, Freud abided by what is, arguably, the first and most fundamental responsibility of the scientific enterpr...
Conflict Negotiation Tactics in Romantic Relationships in High School Students

To investigate how teenagers deal with conflict in romantic relationships, 869 high school students (mean age 16, range 14–19), experienced in romantic relations, completed a conflict tactic scale (adapted from Rands et al., 1981, and Straus, 1979). A principal components analysis revealed six factors, which in descending frequency of use were Compromise, Distraction, Avoidance, Overt Anger, Seeking Social Support, and Violence. Conflict tactics varied as a function of demographic characteristics. Specifically, older teens used Compromise more than younger; girls used Compromise and Overt Anger more and Distraction less than boys; African-Americans used Violence more and Compromise less than European-Americans, whereas Asian-Americans used Distraction and Avoidance more than European-Americans. To assess predictors of conflict tactics, teens also completed scales assessing self-esteem (Rosenberg, 1965), immature and mature defense mechanisms (Araujo and Steiner, 1998, under review) and internalizing and externalizing problem behaviors (Achenbach, 1966). Each of these was singly and jointly associated with the use of conflict tactics. In multiple regression analyses, the externalizing problem score best predicted Overt Anger and Violence in dealing with romantic conflict, the internalizing problem score best predicted Avoidance and Distraction; whereas the mature defense mechanism score was the best predictor of seeking Social Support and Compromise.
Geographic Variation in Meiotic Instability in Eucheira socialis (Lepidoptera: Pieridae)

We studied four populations of the pierid butterfly Eucheira socialis Westwood, located in the Mexican states of Sinaloa, Durango, Mexico, and Oaxaca. We found extreme geographic variation in spermatogenic abnormalities, including a variable number of chromosomes, irregular pairing of chromosomes, lagging chromosomes in metaphase I, lagging chromosomes in anaphase I, the production of micronuclei, and the failure of some spermatids to condense before maturation. We also present evidence suggesting the production of aneuploid sperm. These abnormalities correlate with previously reported male biases in the primary sex ratio of two of these populations. The population with the greatest bias in sex ratio also exhibited the highest frequencies of spermatogenic abnormalities. Because butterflies have female heterogamety and Eucheira females are XO, a possible mechanism linking the sex ratio biases and these abnormalities is nondisjunction of the X chromosomes during spermatogenesis, yielding disomic X sperm. We conclude that the most parsimonious explanation for the meiotic abnormalities in E. socialis is the presence of supernumerary chromosomes, which are associated with sex ratio biases in other systems.