cssi/SciSciGPT-SciSciNet huggingface dataset:
Transport System A is not responsive to hormonal stimulation in primary cultures of fetal rat hepatocytes

Abstract Hepatocytes isolated from rat fetuses have been shown to contain Systems A, ASC, and N for the Na+-dependent transport of neutral amino acids and the activity of each of these systems is significantly higher in the fetal cells than those of an adult (J. Vadgama and H.N. Christensen, personal communication). In contrast to the hepatocytes isolated from adult or newborn animals, the fetal cells do not respond to insulin, glucagon, or dexamethasone with an increase in System A-mediated transport. The System A activity present in the fetal hepatocytes does undergo adaptive regulation in a manner similar to that seen for adult cells, however, the same is not true for System N. Like the cells isolated from the adult rats, the hepatocytes isolated from fetal liver tissue exhibit an increase in Na+-independent transport with time in culture.
Integrated geologic modeling and reservoir simulation of Umiat: A frozen shallow oil accumulation in national petroleum reserve of Alaska

Abstract Current high oil price and availability of new technologies allow re-evaluation of oil resources previously considered uneconomic. The Umiat oil field is one such resource: a unique, shallow (275−1055 ft), low-pressure (200−400 psia) reservoir within the permafrost zone with no initial gas cap, located north of the Arctic Circle, 80 miles west of the Trans Alaska Pipeline System (TAPS) with an estimated 1.5 billion barrels of oil in place. A static model was built based on reinterpretation of original log and core data and seismic information. A permeability anisotropy ratio of 0.45 was incorporated into the geologic model. A Monte Carlo simulation was conducted to estimate the different degrees of uncertainty in the original oil in place (OOIP) estimates. To cover the wide permeability range (0–500 md), three sand groups (rock types) were defined and assigned appropriate capillary pressure and relative permeability curves. These were included in the dynamic model along with measured PVT data and gas–oil relative permeabilities in the presence of ice to evaluate the performance of immiscible gas injection using a multilateral wagon wheel well pattern with horizontal well length of 1500 ft. The new simulation results show that with 50 years of gas injection, recovery factors for the base case (400 psia injection pressure) and two cases with 600 and 800 psis injection pressures are 10.81%, 13.77%, and 16.66% respectively, keeping other parameters constant. These recovery numbers will reduce by 14% and 9% when producing GOR is restricted to 5000 scf/STB and 10,000 scf/STB, respectively. Due to unknown characteristics of natural fractures, several permeability anisotropy (Kv/Kh) ratios were considered. Simulation results indicate that lower anisotropy ratio will reduce oil recovery, probably due to inhibition in the downward movement of gas. The result obtained by this study contributes to the understanding of uncertainties in resource estimates and evaluating ranges of oil recovery in reservoir modeling. Despite limited data and lack of production history to tune the model, the results demonstrate that the economics of the proposed development plan bear a high degree of uncertainty and risk. These findings strongly encourage the operator to include development plan strategies to reduce the risk and enhance the quantity and quality of input simulation data.
Fast computation of first-order elastic–plastic closures for polycrystalline cubic-orthorhombic microstructures

Abstract In recent papers, we have described a rigorous mathematical procedure for delineating the first-order elastic–plastic closures for polycrystalline microstructures where the crystallographic texture (also called the Orientation Distribution Function or the ODF) was assumed to be the main variable influencing the effective properties. These closures were based on elementary bounding theories, and delineate the complete set of theoretically feasible combinations of effective properties in the selected material system. In this paper, we demonstrate certain key properties of these elastic–plastic closures for the class of cubic-orthorhombic textures that, in turn, facilitate a fast computation of these closures with drastically reduced computational effort. Using the novel methods described herein, we have computed and presented numerous examples of property atlases covering a broad range of cubic materials.
EFFECT OF ENDOGLIN OVEREXPRESSION DURING EMBRYOID BODY DEVELOPMENT

Increasing evidence points to endoglin (Eng), an accessory receptor for the transforming growth factor-β superfamily commonly associated with the endothelial lineage, as an important regulator of the hematopoietic lineage. We have shown that lack of Eng results in reduced numbers of primitive erythroid colonies as well as downregulation of key hematopoietic genes. To determine the effect of Eng overexpression in hematopoietic development, we generated a doxycycline-inducible embryonic stem cell line. Our results demonstrate that induction of Eng during embryoid body differentiation leads to a significant increase in the frequency of hematopoietic progenitors, in particular, the erythroid lineage, which correlated with upregulation of Scl, Gata1, Runx1, and embryonic globin. Interestingly, activation of the hematopoietic program happened at the expense of endothelial and cardiac cells, as differentiation into these mesoderm lineages was compromised. Eng-induced enhanced erythroid activity was accompanied by high levels of Smad1 phosphorylation. This effect was attenuated by addition of a bone morphogenetic protein (BMP) signaling inhibitor to these cultures. Among the BMPs, BMP4 is well known for its role in hematopoietic specification from mesoderm by promoting expression of several hematopoietic genes, including Scl. Because Scl is considered the master regulator of the hematopoietic program, we investigated whether Scl would be capable of rescuing the defective hematopoietic phenotype observed in Eng(-/-) embryonic stem cells. Scl expression in Eng-deficient embryonic stem cells resulted in increased erythroid colony-forming activity and upregulation of Gata1 and Gata2, positioning Eng upstream of Scl. Taken together, these findings support the premise that Eng modulates the hematopoietic transcriptional network, most likely through regulation of BMP4 signaling.
New directions in thrombolytic therapy

Although current thrombolytic agents have proven their clinical benefit, the failure to rapidly reperfuse some patients and the persistent bleeding risk represent areas for improvement in therapy. In the past two years, the field has been advanced by the regulatory approval of agents with greater ease of administration, continued development of new agents and exploration of the use of more advanced antiplatelet therapies in combination with thrombolytic agents. Finally, a new class of directly acting fibrinolytic agents is available.
The Empirical Impact of Bovine Somatotropin on New York Dairy Farms

Data from 259 farms that participated in the Cornell University Dairy Farm Business Summary Project were used to measure the impact of bovine somatotropin (bST) on milk production and profitability per cow. Linear regression was used to estimate the response to bST when other variables were held constant. Bovine somatotropin was a dummy variable for bST use or nonuse in the equations. For farms that used bST on 25% or more of the cow days in 1994, milk production increased by 510 kg per cow. Returns above purchased feed costs increased $153 per cow for farms that used bST. Milk receipts over operating costs increased $120 per cow for farms that used bST. The use of bST was estimated to increase net farm income by $27 per cow, but this estimated coefficient was not statistically different from 0. Differences in costs for labor or veterinary services per cow were not significantly different between farms that used bST and farms that did not use bST.
Towards modeling the behavior of static code analysis tools

This paper presents preliminary results of an independent study to assess the performance of a static code analysis (SCA) tool's ability to detect and identify weaknesses and vulnerabilities in source code. The goal of the study is to model the behavior of static code analysis tools, and predict what SCA tool, or set of SCA tools, should be applied against a given source code to identify weaknesses and vulnerabilities.
Young's modulus, Poisson's ratio and failure properties of tetrahedral amorphous diamond-like carbon for MEMS devices

The elastic and failure mechanical properties of hydrogen-free tetrahedral amorphous carbon (ta-C) MEMS structures were investigated via in situ direct and local displacement measurements by a method that integrates atomic force microscopy (AFM) with digital image correlation (DIC). On-chip MEMS-scale specimens were tested via a custom-designed apparatus that was integrated with an AFM to conduct in situ uniaxial tension tests. Specimens 10 µm and 50 µm wide and of 1.5 µm average thickness were used to measure the elastic properties while 340 µm wide tension specimens with a central elliptical perforation resulting in a stress concentration factor of 27 were tested to investigate local effects on material strength. The Young's modulus, Poisson's ratio and tensile strength were measured as 759 ± 22 GPa, 0.17 ± 0.03 and 7.3 ± 1.2 GPa, respectively. In an effort to understand the effect of local defects and assess the true material strength, the local failure stress at sharp central elliptical notches with a stress concentration factor of 27 was measured to be 11.4 ± 0.8 GPa. The AFM/DIC method provided for the first time local displacement fields in the vicinity of microscale perforations and these displacement fields were in accordance with those predicted by linear elasticity.
Amphiphilic particulate phase semi-interpenetrating polymer networks based on recycled rubber matrix

The goal of this study is to enable the utilization of recycled rubber particles in aqueous media by producing amphiphilic particulate phase semi-interpenetrating polymer networks (PPSIPNs). Rubber granulates obtained from post-consumer rubber items were pulverized into fine particles using a solid state shear extrusion (SSSE) process. Reaction mixtures composed of toluene, acrylic acid (AA) monomer and azobisisobutyronitrile (AIBN) as an oil-soluble initiator were prepared and used to impregnate the produced rubber particles. Toluene was added as a co-swelling agent to induce more swelling of the rubber particles and, consequently, enhancement in the absorption of AA in the rubber network. The swollen particles were introduced into a micro-domain suspension polymerization reactor where the ionic strength of the aqueous phase was sufficient to prevent desorption of AA from the particles during the reaction. This resulted in formation and interpenetration of hydrophilic poly(acrylic acid) in the intermolecular structure of hydrophobic rubber network. The resulting composite particles are water dispersible and suitable for use in a variety of aqueous applications such as, additives to waterborne emulsions and vehicles for wastewater treatment.
Corrigendum to “Visible light induced photodesorption of NO from the α-Cr2O3(0001) surface” [Surface Science 606 (2012) 505–509]

The author wishes to thank Scott Chambers for preparation of the Cr2O3 film. This workwas supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The author would like to apologize for any inconvenience caused.
High performance combinatorial algorithm design on the Cell Broadband Engine processor

The Sony-Toshiba-IBM Cell Broadband Engine (Cell/B.E.) is a heterogeneous multicore architecture that consists of a traditional microprocessor (PPE) with eight SIMD co-processing units (SPEs) integrated on-chip. While the Cell/B.E. processor is architected for multimedia applications with regular processing requirements, we are interested in its performance on problems with non-uniform memory access patterns. In this article, we present two case studies to illustrate the design and implementation of parallel combinatorial algorithms on Cell/B.E.: we discuss list ranking, a fundamental kernel for graph problems, and zlib, a data compression and decompression library. List ranking is a particularly challenging problem to parallelize on current cache-based and distributed memory architectures due to its low computational intensity and irregular memory access patterns. To tolerate memory latency on the Cell/B.E. processor, we decompose work into several independent tasks and coordinate computation using the novel idea of Software-Managed threads (SM-Threads). We apply this generic SPE work-partitioning technique to efficiently implement list ranking, and demonstrate substantial speedup in comparison to traditional cache-based microprocessors. For instance, on a 3.2GHz IBM QS20 Cell/B.E. blade, for a random linked list of 1 million nodes, we achieve an overall speedup of 8.34 over a PPE-only implementation. Our second case study, zlib, is a data compression/decompression library that is extensively used in both scientific as well as general purpose computing. The core kernels in the zlib library are the LZ77 longest subsequence matching algorithm and Huffman data encoding. We design efficient parallel algorithms for these combinatorial kernels, and exploit concurrency at multiple levels on the Cell/B.E. processor. We also present a Cell/B.E. optimized implementation of gzip, a popular file-compression application based on the zlib library. For our Cell/B.E. implementation of gzip, we achieve an average speedup of 2.9 in compression over current workstations.
Determining the impact of instrument variation and automated software algorithms on the TGT in hemophilia and normalized plasma.

Abstract Background Despite increasing recognition as a more precise test of in vivo hemostatic conditions, standardization of the thrombin generation test (TGT) continues to hinder its development as routine clinical practice. Prior efforts largely focused on comparing the effects of experimental conditions and different reagents. Commercialized kits, instruments and software have been introduced to calculate the TG curve and its parameters. However, modified versions of the TGT continue to be used worldwide on a variety of microplate reader instruments and processed using individualized algorithms. No prior study has compared the effect of instrument choice and its inherent noise profile on the processing of the TG curve and its common endpoint parameters. Materials and Methods Hemophilia A plasma supplemented with buffer or Factor VIII, mimicking hemophilic or normalized samples respectively, was monitored for thrombin generation after activation with TF on six different fluorescent microplate readers. Each instrument was optimized for TGT signal recording prior to testing. An automated software package containing various mathematical algorithms was utilized to compute the TG curves and parameters, and compare different TG processing approaches. Results Instruments produced unique noise profiles and end-point parameters that were incomparable in absolute signal terms. Similar relative hemophilic responses were obtained across various instruments when the normalized plasma sample was used as an internal standard. Smoothing algorithms corrected destructive instrument noise. Conclusions Instrument-induced errors from numerical differentiation during TG curve processing cannot be eliminated by external calibrators, and require careful qualification of the instrument and implementation of noise-reducing software algorithms.
11 alpha- and 11 beta-hydroxyprogesterone, potent inhibitors of 11 beta-hydroxysteroid dehydrogenase (isoforms 1 and 2), confer marked mineralocorticoid activity on corticosterone in the ADX rat

The effects of 11 alpha- and 11 beta-hydroxyprogesterone (11 alpha-OHP, 11 beta-OHP), on the activity of the glucocorticoid inactivating enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) were studied. 11 alpha-OHP and 11 beta-OHP were potent inhibitors of both 11 beta-HSD1 in rat liver microsomes and 11 beta-HSD2 in lysates of JEG-3 cells, a human choriocarcinoma cell line. In addition, both progesterone metabolites were markedly potent in conferring mineralocorticoid activity upon B in the adrenalectomized rat. These results provide insight into the structural properties required of inhibitors of 11 beta-HSD activity and indicate a possible role for endogenous 11 beta-HSD inhibitors in the regulation of glucocorticoid-induced Na+ retention.
Psychiatric comorbidity in veterans with psychogenic seizures

Abstract Psychogenic non-epileptic seizures (PNES) are frequently encountered in epilepsy monitoring units (EMU) at Veterans Affairs Medical Centers (VAMCs) and cause significant long-term disability. An understanding of psychiatric factors associated with PNES could aid in earlier diagnosis and treatment. We studied 50 consecutive veterans diagnosed with PNES and 37 veterans diagnosed with epileptic seizures (ES), evaluated at a VAMC EMU. We reviewed all available mental health evaluations prior to EMU evaluation. Univariate comparisons included axis I diagnoses, axis II diagnoses, and psychiatric hospitalizations. Predictive models of seizure classification were evaluated by logistic regression. A diagnosis of post-traumatic stress disorder (PTSD) preceded the diagnosis of PNES in 58% of patients and the diagnosis of ES in 13.5% (p
Understanding Diversity Through Social and Community Inquiry: An Action-Research Study

This article describes a portion of a long-term, action-research project investigating the teaching of an elementary social studies methods course for preservice teachers from a social justice fram...
A Distributed Memory Hierarchy and Data Management for Interactive Scene Navigation and Modification on Tiled Display Walls

Simultaneous modification and navigation of massive 3D models are difficult because repeated data edits affect the data layout and coherency on a secondary storage, which in turn affect the interactive out-of-core rendering performance. In this paper, we propose a novel approach for distributed data management for simultaneous interactive navigation and modification of massive 3D data using the readily available infrastructure of a tiled display. Tiled multi-displays, projection or LCD panel based, driven by a PC cluster, can be viewed as a cluster of storage-compute-display (SCD) nodes. Given a cluster of SCD node infrastructure, we first propose a distributed memory hierarchy for interactive rendering applications. Second, in order to further reduce the latency in such applications, we propose a new data partitioning approach for distributed storage among the SCD nodes that reduces the variance in the data load across the SCD nodes. Our data distribution method takes in a data set of any size, and reorganizes it into smaller partitions, and stores it across the multiple SCD nodes. These nodes store, manage, and coordinate data with other SCD nodes to simultaneously achieve interactive navigation and modification. Specifically, the data is not duplicated across these distributed secondary storage devices. In addition, coherency in data access, due to screen-space adjacency of adjacent displays in the tile, as well as object space adjacency of the data sets, is well leveraged in the design of the data management technique. Empirical evaluation on two large data sets, with different data density distribution, demonstrates that the proposed data management approach achieves superior performance over alternative state-of-the-art methods.
Tensile strength of a new suture for fixation of tendon grafts when using a weave technique.

Purpose To evaluate a new corner stitch construct for tendon graft or tendon transfer fixation and compare the tensile strength with a conventional central cross-suture design in human cadaver tendons. Methods Flexor digitorum profundus tendons of the index, middle, and ring fingers (48 total) were used as recipients and palmaris longus, extensor indicis proprius, and extensor digitorum communis tendons of the index finger (48 total) were used as grafts from 16 fresh-frozen human cadaver hands. We compared the cross-stitch technique with a new corner stitch technique in tendon repairs made with 1, 2, or 3 weaves (8 per group). Tendons were sutured at each weave with either 2 full-thickness cross-stitches or 4 partial-thickness corner stitches of 4-0 nylon. Mattress sutures also were placed through the free tendon end for each repair type. The tensile strength of the tendon–graft composite was measured with a materials testing machine. Results The tensile strength of the repairs increased significantly with the number of weaves. When 2 or 3 weaves were used with the corner stitch or when 3 weaves were used with the cross-stitch, the repairs were significantly stronger. Although no significant difference in strength to failure was noted when comparing cross and corner stitches with equivalent numbers of weaves, qualitatively there was a difference in mode of failure with the 3-weave corner stitches failing primarily by intrasubstance tendon failure and the 3-weave cross-stitch repairs failing by tendon pullout. Conclusions The corner stitch is as strong as conventional cross-stitch repairs and its superficial placement may be more favorable to tendon blood supply. This repair may be advantageous for clinical applications.
Eu3+ spectroscopy at charged interfaces. Spectral shift, lifetime and energy transfer characteristics for charged latex spheres

Abstract The interfacial properties of carboxylated latex spheres are studied using environment-sensitive laser excitation spectroscopy of the Eu 3+ ion. The narrow spectral absorption bandwidth of the ion permits resolution of the absorption bands of surface bound and aqueous ions. Eu 3+ ions in a specific environment are then selectively excited to determine their lifetimes and energy transfer properties since these observations give residual waters of hydration and ion-ion distances, respectively. The carboxylated latex spheres in solution produce a single additional absorption line. Lifetime measurements show that the ion binds and loses about half its waters of hydration for the highly charged surface while energy transfer from Eu 3+ to Nd 3+ for these highly charged surfaces gives an ion separation that is consistent with the known average separation of the surface sites. For less highly charged surfaces, these energy transfer separation distance are smaller than the surface site-site separation indicating energy transfer between surface bound and interfacial ions.
Multimodality Treatment of Deep Arteriovenous Malformations: Thalamus Basal Ganglia and Brain Stem

THE THERAPEUTIC APPROACH toward arteriovenous malformations (AVMs) located in the basal ganglia, thalamus, and brain stem has evolved from microsurgical resection as the predominant therapy to a combination of microsurgery, embolization, and radiosurgery. This multimodality treatment was used in the management of 32 patients with deep AVMs of all sizes. Twenty-two patients with surgically accessible AVMs (i.e., typically located in the brain stem and thalamus) underwent microsurgical resection. The AVMs of half of these patients were devascularized preoperatively with transfemoral embolization. Five patients with residual AVMs were then treated with radiosurgery. Ten patients had AVMs, typically located in the basal ganglia, that were surgically inaccessible. These patients underwent embolization to reduce the AVM size, and the postembolization nidus was then treated with radiosurgery. For patients treated early in the series with a predominantly surgical approach, the complete resection rate was 43%. For patients treated later in the series after radiosurgery was incorporated into the management scheme, the complete elimination rate was 72%. Overall, there were no deaths in this series, and the permanent treatment-associated morbidity rate was 9%. These results indicate that an individualized, multimodality approach can be used to eliminate both large and small deep AVMs with an acceptably low morbidity and mortality rate.
Optimal sequences in stochastic single machine shops

Abstract This article addresses the problem of sequencing a given set of jobs with random processing times for uninterrupted processing on a single machine. The objective is to identify the “optimal” sequence which minimizes the expected value of a “scheduler's” disutility (or cost) function with respect to a performance measure. The general problem is difficult to solve; however, special cases can be modeled and solved exactly when (1) processing times are statistically independent, (2) disutility functions for sequence evaluation are linear, exponential, or quadratic, and (3) performance measures are mean flow time, mean waiting time, or mean lateness. Illustrative examples demonstrate that the proposed models create sequences which are (a) influenced by both schedulers' risk taking behavior and the stochasticity of processing times, and (b) more “realistic” than those provided by the classical single machine models. This paper also extends the developed models to include multi-dimensional deterministic single machine problems.
Modern dependency: A “crucial case” study of Brazilian government policy in the minicomputer industry

Brazil’s minicomputer industry has become dependent on government import policy, government financing and domestic private business. The growth in the domestic component of this industry between 1974 and 1981 suggests that incremental government policies (short of a transformation to socialism) can alter Brazil’s level of dependency on MNCs, concerning at least one industry–the minicomputer industry. Therefore, the Brazilian minicomputer model advances the dependency question from “what is dependency and why does it exist?” to “how can one improve its position in a dependency situation?” Relative success in the minicomputer industry cannot be construed as victory over Brazil’s dependency on MNCs, which may alter its economic and political relationship with other countries. Instead, it illustrates a viable model for improving a developing country’s dependency situation. This infant industry strategy is given more credence due to the rekindling of protectionism by all nations. A definitive evaluation of Brazil’s minicomputer policies cannot be rendered until this industry has progressed in its growth cycle. As indicated earlier, signs of both success and failure are evident. In addition, several events may restrict growth in Brazilian minicomputer firms: (1) restriction of funds due to the enormous foreign debt, (2) corrupt or inappropriate management, (3) unsuccessful transfer of technology, or (4) intrusion of smaller and less expensive microcomputers into uses now served by minicomputers. Thus, how effectively Brazil can get out of its overall dependency trap will depend not only on how well it can apply the minicomputer industry model to other industries, of course, given that the model does succeed in the long–run. But it will also depend on how well Brazil can deal with the problems listed above. 0259 0255 V 2
Using Animated Films to Teach Social and Personality Development

Students in a course on Social and Personality Development wrote term papers about 10 aspects of child and adolescent development depicted in an animated film of their choice. Film analysis required using theory and research from the course. The assignment received favorable ratings. The animated film assignment appears to improve students' understanding of course material and helps students evaluate the types of films that children frequently see.
The Contribution of Benzene to Smoking-Induced Leukemia

Cigarette smoking is associated with an increased risk of leukemia; benzene, an established leukemogen, is present in cigarette smoke. By combining epidemiologic data on the health effects of smoking with risk assessment techniques for low-dose extrapolation, we assessed the proportion of smoking-induced total leukemia and acute myeloid leukemia (AML) attributable to the benzene in cigarette smoke. We fit both linear and quadratic models to data from two benzene-exposed occupational cohorts to estimate the leukemogenic potency of benzene. Using multiple-decrement life tables, we calculated lifetime risks of total leukemia and AML deaths for never, light, and heavy smokers. We repeated these calculations, removing the effect of benzene in cigarettes based on the estimated potencies. From these life tables we determined smoking-attributable risks and benzene-attributable risks. The ratio of the latter to the former constitutes the proportion of smoking-induced cases attributable to benzene. Based on linear potency models, the benzene in cigarette smoke contributed from 8 to 48% of smoking-induced total leukemia deaths [95% upper confidence limit (UCL), 20-66%], and from 12 to 58% of smoking-induced AML deaths (95% UCL, 19-121%). The inclusion of a quadratic term yielded results that were comparable; however, potency models with only quadratic terms resulted in much lower attributable fractions--all < 1%. Thus, benzene is estimated to be responsible for approximately one-tenth to one-half of smoking-induced total leukemia mortality and up to three-fifths of smoking-related AML mortality. In contrast to theoretical arguments that linear models substantially overestimate low-dose risk, linear extrapolations from empirical data over a dose range of 10- to 100-fold resulted in plausible predictions.
Conceptual Framework and Research Methods for Migration and HIV Transmission Dynamics

Migration and mobility have had a profound influence on the global HIV epidemic. We propose a network-dyadic conceptual model to interpret previous literature and inform the development of future research with respect to study design, measurement methods, and analytic approach. In this model, HIV transmission is driven by risk behaviors of migrants that emerges and is enabled by mobility, the bridging of sub-epidemics across space and time, and the displacement effects on the primary residential sending community for migrants. To investigate these causal pathways, empirical study designs must measure the relative timing of migratory events, sexual risk behaviors, and incident HIV infections. Network-based mathematical models using empirical data on partnerships help gain insight into the dynamic disease transmission systems. Although the network-dyadic conceptual model and related network methods may not address all questions related to migration and HIV, they provide a unified approach for future research on this important topic.
Diode-laser measurements of linestrength and temperature-dependent lineshape parameters for H2O transitions near 1.4 μm using Voigt, Rautian, Galatry, and speed-dependent Voigt profiles

Abstract Linestrengths and lineshapes for 7 H2O absorption transitions in the ν 1 + ν 3 combination band near 1.4 μm were measured at high resolution using tunable diode laser absorption. H2O- and N2-perturbed lineshapes were measured at 300–1300 K and 2–760 Torr and Voigt, Galatry, Rautian, and quadratic-speed-dependent-Voigt profiles were least-squares fit to measured spectra using a multi-spectrum fitting routine. Transitions with J ″ of 6–18 were studied to highlight the importance of collisional resonance and illustrate how the best-fit lineshape parameters varied with J ″ . The accuracy of the Voigt profile decreased as J ″ increased (especially for J = K c doublets). For transitions in N2, the collisional-broadening temperature exponents varied from ≈ 0.8 to −0.4 (for the Voigt profile) as J ″ increased and this behavior coincided with increasing speed-dependent collisional-broadening coefficients. The quadratic-speed-dependent Voigt profile was found to offer the best combination of accuracy and robust lineshape parameters; however, Rautian and Galatry profiles provided similar performance.
Comment on "Spontaneous radiative coupling of atomic energy levels"

Recently Cardimona and Stroud emphasized that, when the energy levels of an atom are degenerate or nearly so, there can exist a strong radiative interaction between different spontaneous transitions of the atom. This interaction is described by the generalized damping terms and generalized frequency-shift terms in the equation of motion for the atomic density matrix. We here point out that the generalized damping terms can play an important role in the absence of degeneracy for systems other than atoms, and cite the harmonic oscillator as an example. Specifically, we show that these terms are needed for a proper classical limit of radiation damping, and that a small anharmonicity can have a very large effect on the radiative decay rate of the oscillator's amplitude.
Understanding Influence in Multivariate Regression

Multivariate regression influence measures contain a dimension of synergistic interaction not present in univariate regression. This is primarily due to the covariance structure among the multiple dependent variables. Even considering only single cases, the influence can be decomposed into a leverage component and a residual component. This residual term can be further decomposed into residual effects due to the individual dependent variates, and an additional component that measures the joint contribution due to the covariance. Such a decomposition is useful to the investigator in attributing the cause and recommending accommodation of influential cases.
The 2004 Biophysical Society-Avanti Award in Lipids address: roles of bilayer structure and elastic properties in peptide localization in membranes.

Abstract This review details how bilayer structural/elastic properties impact three distinct areas of biological significance. First, the partitioning of melittin into bilayers and melittin-induced bilayer leakage depended strongly on bilayer composition. The incorporation of cholesterol into phosphatidylcholine bilayers decreased melittin-induced leakage from 73 to 3%, and bilayers composed of lipopolysaccharide (LPS), the main lipid on the surface of Gram-negative bacteria, also had low (3%) melittin-induced leakage. Second, transbilayer peptides of different hydrophobic lengths were largely excluded from bilayer microdomains (“rafts”) enriched in sphingomyelin (SM) and cholesterol, even when the length of the transbilayer peptide domain matched the hydrocarbon thickness of the raft bilayer. This is likely due to the large area compressibility modulus of SM:cholesterol bilayers. Third, the major water barrier of skin, the extracellular lamellae of the stratum corneum, was found to contain tightly packed asymmetric lipid bilayers with cholesterol located preferentially on one side of the bilayer and a unique skin ceramide containing an unsaturated acyl chain on the opposite side. We argue that, in each of these three areas, key factors are differences in lipid hydrocarbon chain packing for different lipids, particularly the tight hydrocarbon chain packing caused by cholesterol’s strong interaction with saturated chains.
Harvesters and High Finance: Formation of the International Harvester Company

Through an analysis of the formation of the International Harvester Company in 1902, Professor Kramer presents a suggestive case-study in businessmen's motivations toward merger.
Collisions between Small Precipitation Drops. Part III: Laboratory Measurements at Reduced Pressure.

Abstract Collisions between drops in free fall were measured at atmospheric pressures of 745 and 545 mb for sizes applicable to self-collection, the process that controls the spreading of precipitation drop distributions in the warm rain process. Orthogonal cameras were used to obtain the horizontal offset of drops of 200–425-μm radii before collision and the outcome after collision. The effect of air pressure on collision outcomes for negligibly charged drops at high relative humidity was evaluated using three different drop size pairs at reduced pressure over a range of impact Weber numbers (We = 5.7–16.6) as well as four drop size pairs from previous experiments at 1000 mb for We ≤ 9.6. The collision outcomes in the collision cross section of the seven experiments consisted of a central region of coalescence and an outer region of bounce. For the three experiments with We > 9, the outcome pattern included a region of temporary coalescence at larger offsets that spread into the central region of permane...
Effects of Helicobacter pylori on proliferation of gastric epithelial cells in vitro.

Abstract OBJECTIVE: H. pylori infection of the gastric mucosa has been associated with an increase in gastric epithelial cell proliferation. However, in vitro adherence of H. pylori to gastric epithelial cells is associated with reduced cell proliferation. Reduction of epithelial cell proliferation may contribute to ulcer formation and delay ulcer healing. The following study was undertaken to elucidate the ability of cagA -positive and -negative strains to impede gastric epithelial cell proliferation. METHODS: A human gastric adenocarcinoma cell line (AGS) was overlaid with either cagA -positive or cagA -negative H. pylori strains suspended in cell culture medium. Proliferation of AGS cells was analyzed by performing direct cell counts and by measuring metabolism of a soluble tetrazolium compound (MTS), after exposure to H. pylori for 24 h. RESULTS: When compared with control cells cultured in medium alone, AGS cell proliferation was reduced by 45.6% and 28.5% due to exposure to cagA -negative and cagA -positive strains, respectively. When bacterial-induced cytotoxicity was assessed by measuring release of lactose dehydrogenase (LDH) into the culture medium, cagA -positive strains were shown to induce significantly more cytotoxicity than cagA -negative strains. CONCLUSIONS: These experiments demonstrate that H. pylori exposure to AGS cells significantly reduces cell proliferation. However, cagA -positive strains that induce more cell injury reduce cell proliferation to a lesser extent than cagA -negative strains. Persistent replication of gastric epithelial cells injured by exposure to cagA -positive strains may be partially responsible for the stronger association with gastric cancer in persons infected with cagA -positive H. pylori strains.
C-reactive protein and the risk of incident colorectal cancer.

ContextInflammation may play a role in the pathogenesis of colorectal cancer; however, epidemiological evidence supporting this hypothesis in average-risk persons is sparse.ObjectiveTo determine the risk of incident colon and rectal cancer associated with elevated baseline plasma concentrations of C-reactive protein (CRP).Design, Setting, and ParticipantsProspective, nested case-control study of a cohort of 22 887 adults (>18 years and Washington County, Maryland, residents) enrolled between May and October 1989 and followed up through December 2000. A total of 172 colorectal cancer cases were identified through linkage with the Washington County and Maryland State Cancer registries. Up to 2 controls (n = 342) were selected from the cohort for each case and matched by age, sex, race, and date of blood draw.Main Outcome MeasureOdds ratio (OR) of incident colon and rectal cancer.ResultsPlasma CRP concentrations were higher among all colorectal cases combined than controls (median CRP, 2.44 vs 1.94 mg/L; P = .01). The highest concentration was found in persons who subsequently developed colon cancer vs matched controls (median CRP, 2.69 vs 1.97 mg/L; P<.001). Among rectal cancer cases, CRP concentrations were not significantly different from controls (median CRP, 1.79 vs 1.81 mg/L; P = .32). The risk of colon cancer was higher in persons in the highest vs lowest quartile of CRP (OR, 2.55; 95% confidence interval [CI], 1.34-4.88; P for trend = .002). In nonsmokers, the corresponding association was stronger (OR, 3.51; 95% CI, 1.64-7.51; P for trend<.001). A 1-SD increase in log CRP (1.02 mg/L) was associated with an increased risk of colon cancer after adjusting for potential confounders and excluding cases occurring within 2 years of baseline (OR, 1.35; 95% CI, 1.05-1.74) or excluding those with late-stage colon cancer at the time of diagnosis (OR, 1.38; 95% CI, 0.99-1.91).ConclusionsPlasma CRP concentrations are elevated among persons who subsequently develop colon cancer. These data support the hypothesis that inflammation is a risk factor for the development of colon cancer in average-risk individuals.
Profiling adjustment among postsecondary students with disabilities: A person-centered approach.

The current investigation examines profiles of postsecondary adjustment among college students with disabilities. Students’ self-perceptions of practical gains, personal gains, educational gains, their overall satisfaction with postsecondary school, and their college GPA were subjected to a latent profile analysis. Results indicated that students fell into 1 of 3 profiles (i.e., poorly adjusted, average adjusted, or highly adjusted) but were overrepresented in the poorly adjusted profile. Follow-up analyses conducted to explore skills and processes associated with adjustment status indicated that students in the poorly adjusted group had significantly lower self-efficacy, self-advocacy, family support, and perceptions of campus climate than did students in the average and highly adjusted groups. Adjustment profiles did not differ on several other theoretically relevant variables, including time spent studying, high school GPA, disability supports, and financial stress. The implications of these findings for secondary special education teachers, university disability support personnel, and postsecondary students with disabilities are discussed.
Postpartum myocardial infarction treated with percutaneous transluminal coronary angioplasty.

We report herein the first case of acute revascularization by percutaneous transluminal coronary angioplasty (PTCA) in postpartum MI
Reusable, extendible flight software for a planetary spacecraft prototype testbed

As part of the 'Faster, Better, Cheaper' paradigm for NASA missions, the Jet Propulsion Laboratory (JPL) is developing a Flight System Testbed for prototyping and early integration of future planetary missions. This paper describes the development of a set of reusable, extendible spacecraft flight software to be used as a basis for prototypes in the testbed. This effort has focused on identification and implementation of functions which are common across multiple missions. This effort has also developed an intertask messaging system which supports modification of existing functions, additions of new functions, and porting to various computation and input/output (I/O) architectures. This paper also identifies a number of other JPL activities which support standardization and reusability of planetary spacecraft designs.
Do Exam Policies Matter in College

This paper uses the binary logistic regression to show how exam policies affect students’ learning outcomes. Types of examinations employed by instructors are divided broadly into three, namely traditional, nontraditional, and project. Using data from an undergraduate business program, the study develops a binary logistic regression model predicting the effects of the three types of examinations on students’ learning outcomes. The results showed that the traditional (in-class) examinationhad the largest predictive powers on students’ learning outcomes. Nontraditional examination and project had significantly lesser predictive powers than traditional examination, with project having the least powers. The findings suggest, first, that instructors’ examination policies may be less impactful or have negative effects on learning outcomes; second, there can be a particular combination of traditional, nontraditional, and project examinations, which can most effectively boost students’ learning outcomes; third, students who participate in academic program with higher correctly classified estimates would be expected to acquire higher learning outcomes than students who participate in an academic program with significantly lower correctly classified estimates; fourth, examination policies can be deployed as a critical tool for students’ learning outcomes; and, fifth, a periodic evaluation of examination policies in an academic program may be useful.
Impaired crossed facilitation of the corticospinal pathway after cervical spinal cord injury.

In uninjured humans, it is well established that voluntary contraction of muscles on one side of the body can facilitate transmission in the contralateral corticospinal pathway. This crossed facilitatory effect may favor interlimb coordination and motor performance. Whether this aspect of corticospinal function is preserved after chronic spinal cord injury (SCI) is unknown. Here, using transcranial magnetic stimulation, we show in patients with chronic cervical SCI (C5–C8) that the size of motor evoked potentials (MEPs) in a resting intrinsic hand muscle remained unchanged during increasing levels of voluntary contraction with a contralateral distal or proximal arm muscle. In contrast, MEP size in a resting hand muscle was increased during the same motor tasks in healthy control subjects. The magnitude of voluntary electromyography was negatively correlated with MEP size after chronic cervical SCI and positively correlated in healthy control subjects. To examine the mechanisms contributing to MEP crossed facilitation we examined short-interval intracortical inhibition (SICI), interhemispheric inhibition (IHI), and motoneuronal behavior by testing F waves and cervicomedullary MEPs (CMEPs). During strong voluntary contractions SICI was unchanged after cervical SCI and decreased in healthy control subjects compared with rest. F-wave amplitude and persistence and CMEP size remained unchanged after cervical SCI and increased in healthy control subjects compared with rest. In addition, during strong voluntary contractions IHI was unchanged in cervical SCI compared with rest. Our results indicate that GABAergic intracortical circuits, interhemispheric glutamatergic projections between motor cortices, and excitability of index finger motoneurons are neural mechanisms underlying, at least in part, the lack of crossed corticospinal facilitation observed after SCI. Our data point to the spinal motoneurons as a critical site for modulating corticospinal transmission after chronic cervical SCI.