cssi/SciSciGPT-SciSciNet huggingface dataset:
The Importance of the Retail Payment System

This article explores the importance of an efficient retail payment system and develops an integrated framework for evaluation of the retail payment system by policy makers. It examines the costs and benefits of the various types of retail payment system, focusing on the seven desirable benefits of the retail payment system: (1) finality and reversibility; (2) universality (ability to use at point of sale and remotely); (3) recordkeeping; (4) liquidity (maximizing interest earning assets); (5) security and safety; (6) financial inclusion and access; and (7) fungibility and ease of use (seven benefits).The article discusses the Coase Theorem, a proposition from transaction cost economics that provides a useful tool for analyzing transaction efficiency. Increased costs are not bad per se since parties are often willing to incur higher costs to achieve their desired results, e.g. higher costs for a more secure form of payment. Indeed, higher costs may often generate higher value to both parties to a transaction. What one wants to reduce are “friction” costs, costs that neither party wants to pay to achieve a desired result, e.g. higher costs produced by lack of information.While each retail payment system provides certain advantages, e.g. cash for small transactions, overall the analysis suggests that debit and credit cards represent the most desirable payment system for achieving the seven benefits set forth above. This is supported by statistics that indicate that retail payments have increasingly moved toward card payments.
Brain image analysis by using sensor-array-signal processing technique

Various imaging modalities such as MRI, X-ray CT, PET/SPECT, and MR-angiography are used for brain imaging. The authors provides a non-model-based image analysis technique for these imaging modalities. In this approach, the brain tissue type and organ structure are represented by the image regions. The technique formulates the region detection problem in a multidimensional signal processing framework such that a signal structure similar to sensor-array-processing signal presentation is created and the advanced sensor-array-signal processing techniques are employed. Following the region detection, the image analysis is performed by segmentation which is completed by region parameter estimation and pixel classification. The proposed technique is an unsupervised, eigenstructure approach. It eliminates the ad-hoc assumptions in image modeling, and possesses extensive computation speed superiority over existing model-based approaches. The most important feature is that it properly utilizes the spatial correlations among the pixels. The results obtained by applying this technique to the simulated, MRI, CT, PET/SPECT, and MR-angiography images demonstrate its promise and effectiveness. The major applications of this technique in the brain image analysis are the tissue classification and quantification. >
New regulatory interactions and cellular responses in the isthmic organizer region revealed by altering Gbx2 expression.

The mouse homeobox gene Gbx2 is first expressed throughout the posterior region of the embryo during gastrulation, and becomes restricted to rhombomeres 1-3 (r1-3) by embryonic day 8.5 (E8.5). Previous studies have shown that r1-3 do not develop in Gbx2 mutants and that there is an early caudal expansion of the midbrain gene Otx2 to the anterior border of r4. Furthermore, expression of Wnt1 and Fgf8 , two crucial components of the isthmic organizer, is no longer segregated to adjacent domains in Gbx2 mutants. In this study, we extend the phenotypic analysis of Gbx2 mutants by showing that Gbx2 is not only required for development of r1-3, but also for normal gene expression in r4-6. To determine whether Gbx2 can alter hindbrain development, we generated Hoxb1-Gbx2 ( HG ) transgenic mice in which Gbx2 is ectopically expressed in r4. We show that Gbx2 is not sufficient to induce r1-3 development in r4. To test whether an Otx2/Gbx2 interface can induce r1-3 development, we introduced the HG transgene onto a Gbx2 -null mutant background and recreated a new Otx2/Gbx2 border in the anterior hindbrain. Development of r3, but not r1 and r2, is rescued in Gbx2 –/– ; HG embryos. In addition, the normal spatial relationship of Wnt1 and Fgf8 is established at the new Otx2/Gbx2 border, demonstrating that an interaction between Otx2 and Gbx2 is sufficient to produce the normal pattern of Wnt1 and Fgf8 expression. However, the expression domains of Fgf8 and Spry1, a downstream target of Fgf8, are greatly reduced in mid/hindbrain junction area of Gbx2 –/– ; HG embryos and the posterior midbrain is truncated because of abnormal cell death. Interestingly, we show that increased cell death and a partial loss of the midbrain are associated with increased expression of Fgf8 and Spry1 in Gbx2 conditional mutants that lack Gbx2 in r1 after E9.0. These results together suggest that cell survival in the posterior midbrain is positively or negatively regulated by Fgf8, depending on Fgf8 expression level. Our studies provide new insights into the regulatory interactions that maintain isthmic organizer gene expression and the consequences of altered levels of organizer gene expression on cell survival.
2000 Joseph E. Whitley, MD, award development and assessment of a radiology core curriculum in health care policy and practice*

Rationale and Objectives. The purpose of this study was to evaluate the feasibility of implementing a core curriculum in health policy and practice for radiology residents and fellows, to determine whether such a curriculum would be considered professionally valuable by participants, and to determine if the curriculum would influence participants' careers. Materials and Methods. A core curriculum in health policy and practice was developed, involving 19 seminars presented over 5 weeks. Twelve faculty members presented comprehensive and integrated information relevant to current and future radiology practice. Topic clusters included health care structure and payment, technology and health services, radiology practice management, and career issues. Classroom teaching was supplemented by a course syllabus and resource library. Participants were surveyed following each seminar and at the conclusion of the curriculum. Results. Participants described their baseline knowledge of each topic as weak. As a result of the curriculum, self-described knowledge ratings increased considerably. Interest in curriculum topics and perception of their importance and relevance to radiology practice increased. Of respondents, 84% (26 of 31) described the curriculum as having very good or excellent educational value. All respondents indicated that the curriculum should be repeated in the future, 42% (13 of 31) indicated that the curriculum motivated them to pursue further related education, and 61% (19 of 31) developed interest in personal involvement in administrative issues and radiology organizations. Conclusion. A core curriculum in health policy and practice was successfully integrated into radiology training. The curriculum resulted in increased knowledge, interest, and perceived importance of medical management issues by residents and fellows and stimulated their interest in pursuing further management education and involvement in radiology administration and organizations.
Changing the economic mechanism in the Soviet Union

Two views of trade prospects with the Soviet Union are offered in this article and a companion study by Messers Coplin and O'Leary, Prof. Naylor is guardedly optimistic, while his brother Soviet watchers are guardedly pessimistic. Moscow has wooed Naylor with private meetings, and he has firsthand experience with this new willingness on the part of the Soviets to be forthright about discussing the problems and future of their system. Coplin and O'Leary are professional power analysts who see Gorbachev's stage as a cramped place with little or no room for fancy fandangos with U.S. business. But both the optimists and pessimists are intrigued by the sparks of change they see flying in the Russian wind.
The impact of race and insurance type on the outcome of endovascular abdominal aortic aneurysm (AAA) repair.

Background Although mortality and complication rates for abdominal aortic aneurysm (AAA) have declined over the last 20 years, operative complication rates and perioperative mortality are still high, specifically for repair of ruptures. The goal of this study was to determine the influence of insurance type and ethnicity while controlling for the influences of potential confounders on procedure selection and outcome following endovascular AAA repair (EVAR). Methods Using the Nationwide Inpatient Sample (NIS) database, we identified patients who underwent EVAR repair of ruptured and elective infrarenal AAA, between 1990 and 2003. Insurance type and ethnicity were analyzed against the primary outcome variables of mortality and major complications. The potential confounders of age, gender, operative location, diabetes, and Deyo index of comorbidities, were controlled. Results Bivariate analyses demonstrated significant differences between insurance types and ethnicity and mortality and complications. Patients who were self pay had adverse outcomes in comparison to Private insurance. Whites encountered less perioperative mortality and postoperative complications than Blacks and Hispanics. Conclusions After controlling for previously identified associative factors for AAA outcome, ethnicity and insurance type does influence EVAR surgical outcome. Subsequent studies that break down emergent repair vs elective surgery and that longitudinally stratify delay in surgery, or time to admission may be useful.
Practice and Teaching of American Water Management in a Changing World

Once upon a time the United States was the undisputed leader of the world. In that era the United States was also the undisputed leader in the practice of water resources development and management, and in the education of water professionals and future leaders from around the world. This editorial argues that time has passed, and that now is the time for a major rethink if the United States is to regain the role as a world leader of both water resource practice and graduate education. By way of preface, over the past 40 years I have engaged with water management in the developing world from many perspectives: in the Ministry of Water in my home country of South Africa; as a graduate student working on India and Pakistan in the Harvard Water Program; as an epidemiologist at the Cholera Research Laboratory in Bangladesh; as an engineer in the Ministry of Water in newly independent Mozambique; working on Africa and the Philippines as a professor of water resources at the University of North Carolina, and for the last twenty years in Asia, Latin America, and Africa in a variety of operational and policy positions in the World Bank. Of particular relevance for this editorial are my two final World Bank assignments: for three years as the World Bank’s senior water advisor in New Delhi, and for three years as the World Bank’s country director for Brazil. Now I am a faculty member in the School of Engineering and Applied Sciences at Harvard, charged with developing a new universitywide “Harvard Water Initiative.” Over the course of this life in water, I have seen, from the rivers’ edge, as it were, dramatic changes in global power, in ideas as much as finance. This experience suggests that just as the United States has lost its unquestioned global economic preeminence and is having to learn to see the world through a different economic lens, so, too, the U.S. water community is losing its preeminence in the practice and education of water resource management. This editorial outlines some ideas that might be relevant to a rethink in both the practical and educational spheres. I start with a few observations.
“GOTCHA!” Twenty-Five Behavior Traps Guaranteed to Extend Your Students' Academic and Social Skills:

Describes effective natural reinforcers that teachers can use in the classroom to help students develop positive and constructive knowledge and skills
Synchronized Oscillations in Hydrogen Bridges

MOST of the compounds now known to contain intramolecular hydrogen bridges can be represented1 by the formulae: in which X and Y denote oxygen or nitrogen atoms. As indicated, there is undoubtedly resonance between the two extreme structures represented. An equally important but apparently hitherto overlooked stabilizing factor is the tendency of the electron distribution around the ring to shift in synchronism with the oscillational motion of the bridge hydrogen. The electron shifts produced by motion of this hydrogen in the direction X—Y decrease the X—H attraction and increase the Y—H attraction. As a result, the small energy hump which would probably otherwise exist2 in the centre of the bridge is greatly reduced or eliminated entirely, and the bridge stability is increased.
Integrated magneto-optic waveguide material structures and devices

Recent advances in the preparation of B i- and Ce- substituted (doped) yttrium iron garnet (YIG) films on gadolinium gallium garnet (GGG) and semiconductor substrates such as gallium arsenide (GaAs), the design of hybrid material structures, and the construction of wideband integrated microwave and magnetooptic (MO) devices, and their potential applications are presented.
Training Needs Analysis and Evaluation for New Technologies through the Use of Problem-Based Inquiry.

ABSTRACT The analysis of calls to a help desk, in this case calls to a computer help desk, can serve as a rich source of information on the real world problems that individuals are having with the implementation of a new technology. Thus, we propose that an analysis of help desk calls, a form of problem-based inquiry, can serve as a fast and low cost means of both analyzing training needs and evaluating training. We illustrate the use of problem-based inquiry through a case study of the analysis of help desk calls made after the delivery of a training program that served to introduce a new type of document management system in a professional services firm. Based on the analysis of help desk calls it should be possible to modify future training so as to enhance transfer to the job environment.
Experimental sensorless vector control performance of a DFIG based on an extended Kalman filter

Doubly fed induction generators (DFIGs) are used in variable speed wind energy conversion systems. Field oriented control (FOC) of this type of generators requires the availability of a rotor position measurement or estimation. Hence, for sensorless implementations, rotor position observers have to be integrated to the control algorithm. In this paper, the observability of the DFIG is analyzed and an extended Kalman filter (EKF) is proposed as rotor position observer. The performance of the EKF is verified experimentally in a 4[kW] prototype.
From Inhumane to Humane: A Longitudinal Study of Leadership Transformation

Phenomenological interview methods were completed with 9 mental health professionals (psychologists, counselors) who volunteered as Red Cross Disaster Mental Health Workers in response to the 9/11 disaster in New York. Interviews were completed shortly after the disaster and repeated 5 years later to understand how 9/11 experiences changed participants' leadership in their work. The unprecedented characteristics of the 9/11 disaster provided a uniquely significant context for the leadership demands for workers at 9/11. Experiences at 9/11 continued to impact professional and personal work of the participants in meaningful ways many years after the experiences. Follow-up interviews suggested individual and evolving changes in leadership style and professional practice, ranging from internalized/reflective leaders to externalized/active leaders.
Activation-independent binding of human memory T cells to adhesion molecule ELAM-1

The induction of an ensemble of adhesion molecules on endothelial cells by inflammatory cytokines is likely to be crucial to the differential migration of T-lymphocyte subsets into inflammatory sites. Two molecular pathways involving the VLA-4 and LFA-1 integrins are known to mediate T-cell adhesion to activated endothelium. Here we show that a third pathway involving the rapidly inducible endothelial cell-surface adhesion molecule ELAM-1 contributes to the binding of resting CD4+ T cells to IL-1-induced human endothelial cells. All three pathways contribute to the greater adhesion to endothelium of memory T cells than naive T cells. There are two unique features of T-cell adhesion to purified ELAM-1: first, ELAM-1 exclusively mediates adhesion of memory T cells; second, memory T-cell binding to ELAM-1 is independent of acute activation events that regulate integrin-mediated adhesion. Thus, ELAM-1 may be of primary importance in the initial attachment of memory T cells to inflamed endothelium in vivo and to the preferential migration of memory T cells into tissue and inflammatory sites.
Functional Analysis of a Troponin I (R145G) Mutation Associated with Familial Hypertrophic Cardiomyopathy

Familial hypertrophic cardiomyopathy has been associated with several mutations in the gene encoding human cardiac troponin I (HCTnI). A missense mutation in the inhibitory region of TnI replaces an arginine residue at position 145 with a glycine and cosegregates with the disease. Results from several assays indicate that the inhibitory function of HCTnI(R145G) is significantly reduced. When HCTnI(R145G) was incorporated into whole troponin, Tn(R145G) (HCTnT small middle dotHCTnI(R145G) small middle dotHCTnC), only partial inhibition of the actin-tropomyosin-myosin ATPase activity was observed in the absence of Ca(2+) compared with wild type Tn (HCTnT small middle dotHCTnI small middle dotHCTnC). Maximal activation of actin-tropomyosin-myosin ATPase in the presence of Ca(2+) was also decreased in Tn(R145G) when compared with Tn. Using skinned cardiac muscle fibers, we determined that in comparison with the wild type complex 1) the complex containing HCTnI(R145G) only inhibited 84% of Ca(2+)-unregulated force, 2) the recovery of Ca(2+)-activated force was decreased, and 3) there was a significant increase in the Ca(2+) sensitivity of force development. Computer modeling of troponin C and I variables predicts that the primary defect in TnI caused by these mutations would lead to diastolic dysfunction. These results suggest that severe diastolic dysfunction and somewhat decreased contractility would be prominent clinical features and that hypertrophy could arise as a compensatory mechanism.
Multilayer adsorption of 3 He and 4 He on zeolite from 4 K to 80 K

The adsorption isotherms of4He, N2, and argon have been measured on synthetic zeolite (Linde Molecular Sieve 13X) at 78 K, and of3He and4He, also on zeolite 13X, in the temperature range 4 K to 20 K. The results are presented in tabular and graphical form. The N2 isotherms, which showed characteristic step-like behavior, served to assess the specific surface area, which was 527 m2 g−1 based on a “standard” N2 molecular area of 16.2 A2. It also provided a value ofE 1 equal to 2530 cal mole−1. The argon isotherm at 78 K yielded a specific surface area for the zeolite 13X in fair agreement with that from the N2 data. Nine isotherms were taken for4He between 4 K and 20 K and four for3He in the same temperature range. These isotherms permitted good evaluations of the isosteric heats of adsorption to be made and plotted as a function of coverage, yielding, for4He,Q st =1580 j mole−1 at zero coverage,Q st =1030 j mole−1 at monolayer coverage andE 2=480 j mole−1 at two-layer coverage. For3He, which showed everywhere smaller Q st values. Q st =1420 at zero coverage. By use of the Steele equation applied to4He, we found that the monolayer coverageV m1 ≈ 0.29 cm3 (STP) m−2, and the second-layer coverage,V m2 ≈ 0.10 cm3 (STP) m−2.
A GPU-based incompressible Navier–Stokes solver on moving overset grids

In pursuit of obtaining high fidelity solutions to the fluid flow equations in a short span of time, graphics processing units GPUs which were originally intended for gaming applications are currently being used to accelerate computational fluid dynamics CFD codes. With a high peak throughput of about 1 TFLOPS on a PC, GPUs seem to be favourable for many high-resolution computations. One such computation that involves a lot of number crunching is computing time accurate flow solutions past moving bodies. The aim of the present paper is thus to discuss the development of a flow solver on unstructured and overset grids and its implementation on GPUs. In its present form, the flow solver solves the incompressible fluid flow equations on unstructured/hybrid/overset grids using a fully implicit projection method. The resulting discretised equations are solved using a matrix-free Krylov solver using several GPU kernels such as gradient, Laplacian and reduction. Some of the simple arithmetic vector calculations are implemented using the CU++: An Object Oriented Framework for Computational Fluid Dynamics Applications using Graphics Processing Units, Journal of Supercomputing, 2013, doi:10.1007/s11227-013-0985-9 approach where GPU kernels are automatically generated at compile time. Results are presented for two-and three-dimensional computations on static and moving grids.
The effect of circadian cycle on the sensitivity to thermal load in the chinchilla

Abstract 1. 1. Experiments were conducted to test the effect of circadian phase on the body temperature response of the chinchilla to thermal load. 2. 2. Exposing the animals at the nadir and rising phase of the normal temperature cycle generated large and significant increases in the body temperature response over time when compared to 25°C controls. 3. 3. The importance of experimental design in minimizing variations to the normal periodic fluctuation in experimental animals is discussed.
Customer Information Quality and Knowledge Management: A Case Study Using Knowledge Cockpit

Information quality has become the number one issue a knowledge worker faces in today’s environment, due to the high noise‐to‐signal ratio of non‐essential content in knowledge repositories and the lack of quality measurement for the information. This paper discusses information organization and retrieval technologies for improving the quality of knowledge by reducing the noise‐to‐signal ratio, and focusing on techniques to abstract data from search results into comprehensible knowledge for users. A case study concerning a customer management system is used to illustrate the ideas.
Conductive component after cochlear implantation in patients with residual hearing conservation.

Purpose Changes in auditory thresholds following cochlear implantation are generally assumed to be due to damage to neural elements. Theoretical studies have suggested that placement of a cochlear implant can cause a conductive hearing loss. Identification of a conductive component following cochlear implantation could guide improvements in surgical techniques or device designs. The purpose of this study is to characterize new-onset conductive hearing losses after cochlear implantation. Method In a prospective study, air- and bone-conduction audiometric testing were completed on cochlear implant recipients. An air–bone gap equal to or greater than 15 dB HL at 2 frequencies determined the presence of a conductive component. Results Of the 32 patients with preoperative bone-conduction hearing, 4 patients had a new-onset conductive component resulting in a mixed hearing loss, with air-conduction thresholds ranging from moderate to profound and an average air–bone gap of 30 dB HL. One had been implanted throu...
Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of Conventional, Central, and Horizontal Single-Bundle Virtual Graft Positions

BackgroundConventional endoscopic single-bundle transtibial anterior cruciate ligament (ACL) reconstruction from the posterolateral tibial footprint to the anteromedial femoral footprint results in a vertical graft. A more oblique horizontal graft from the anteromedial tibial footprint to the posterolateral femoral footprint may offer a better alternative for all endoscopic ACL reconstruction.HypothesisWhen compared with a conventional ACL single-bundle position, the horizontal graft ACL position has more obliquity and so undergoes a greater change in length during anterior translation and internal rotation.Study DesignControlled laboratory study.MethodsA computer navigation system was used to acquire kinematic data during a flexion-extension cycle and outline the anteromedial and posterolateral aspects of the tibial and femoral footprints on 5 fresh-frozen cadaveric knees. Three virtual graft positions were defined: conventional (posterolateral tibia—anteromedial femur), central, and horizontal (anterome...
Bacterial and algal orthologs of prostaglandin H2 synthase: novel insights into the evolution of an integral membrane protein

Abstract Prostaglandin H 2 synthase (PGHS; EC 1.14.99.1), a bi-functional heme enzyme that contains cyclooxygenase and peroxidase activities, plays a central role in the inflammatory response, pain, and blood clotting in higher eukaryotes. In this review, we discuss the progenitors of the mammalian enzyme by using modern bioinformatics and homology modeling to draw comparisons between this well-studied system and its orthologs from algae and bacterial sources. A clade of bacterial and algal orthologs is described that have salient structural features distinct from eukaryotic counterparts, including the lack of a dimerization and EGF-like domains, the absence of gene duplicates, and minimal membrane-binding domains. The functional implications of shared and variant features are discussed.
Immersion and embedding of self-crossing loops

The process of generating a 3D model from a set of 2D planar curves is complex due to the existence of many solutions. In this paper we consider a self-intersecting planar closed loop curve, and determine the 3D layered surface P with the curve as its boundary. Specifically, we are interested in a particular class of closed loop curves in 2D with multiple self-crossings which bound a surface homeomorphic to a topological disk. Given such a self-crossing closed loop curve in 2D, we find the deformation of the topological disk whose boundary is the given loop. Further, we find the surface in 3D whose orthographic projection is the computed deformed disk, thus assigning 3D coordinates for the points in the self-crossing loop and its interior space. We also make theoretical observations as to when, given a topological disk in 2D, the computed 3D surface will self-intersect.
Home care nurses' inferences and decisions

The types of inferences and decisions made by home health nurses were explored in this study. One hundred patient care records representing 10 home care nurses' primary clients were examined. Two main types of decisions were identified: (1) autonomous with the subcategories of self-directed and consultative and (2) collaborative. Less experienced nurses recorded the most decisions and relied on collaborative decision making more often. Implications include the need for increased autonomy in decision making for home care nurses and the necessity for decision supports for novice nurses.
Hypoxic Pulmonary Vasoconstriction in Systemic Sclerosis and Primary Pulmonary Hypertension

Reduction of pulmonary vascular resistance by a high inspired oxygen concentration is a common, but not universal phenomenon in patients with pulmonary vascular disease of varying etiology that may determine their response to long-term domiciliary oxygen therapy. We therefore determined changes in PVR during oxygen therapy in two patient populations not previously studied: systemic sclerosis (n = 8, mean age ± SEM, 44.5 ± 5.4 years) and primary pulmonary hypertension (n = 7, mean age ± SEM 38 ± 7.8 years). All patients were hypoxemic (arterial oxygen tension, on air 9.5 ± 1.2 kPa for SSc and 8.3 ± 0.6 kPa for PPH, p>0.05). Right atrial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, systemic arterial pressure, PaO 2 and cardiac output by thermodilution were measured at three, 20-min intervals while inspiring air and again after inspiring 60 percent oxygen for 30 min. The PVR fell significantly with oxygen in patients with SSc from 797.6 ± 179.2 to 610 ± 151.6 dynes/s/cm −5 (p 2 prior to oxygen therapy (r = 0.86, p −5 , p>0.05) and no predictor of a vasodilator response in individual patients. In SSc, hypoxic pulmonary vasoconstriction contributes more consistently to elevated PVR than in patients with PPH. (Chest 1991; 99:551–56)
Three-region MRI-based whole-body attenuation correction for automated PET reconstruction

Abstract Introduction In this study we proposed and developed a simple attenuation mapping approach based on magnetic resonance imaging (MRI) for the purpose of reconstructing positron emission tomography (PET) images in PET/MRI imaging devices. Methods After experimental development, an in vivo calibration was performed by whole-body scanning of five beagles on both a PET/CT and an MRI. The attenuation was determined by using an automated segmentation algorithm to segment regions of background, lung, soft tissue and bone, and assigning them values of 0.002, 0.030, 0.098 and 0.130 cm −1 , respectively. Results The CT-attenuated and MRI-attenuated PET images had average standardized uptake values (SUVs) that differed by 1–6% for most regions of interest (ROIs). Also, mean relative differences (MRDs) between the images were between 5% and 9% for most regions. The only exception is bone, where the three-region MRI-attenuated PET images had an SUV 10% less on average than the CT-attenuation images, and the MRD averaged 14%. Also, additional segmentation of the bone in the four-region MRI-attenuated PET images reduced the SUV difference to 3% and the MRD to 6%. Conclusion Therefore, despite the improvements in the four-region segmentation, the three-region segmentation, without delineation of osseous tissues, produces high-quality images that are sufficient for most expected clinical and research purposes.
Age-associated decrease of adenylate cyclase activity in rat myocardium

Abstract Myocardial inotropic and chronotropic responses to beta-adrenergic agonists are diminished with aging. Since myocardial beta-adrenergic receptors are unaltered with age, we tested the hypothesis that this decreased responsiveness is related to a defect in the adenylate cyclase system. Isoproterenol-stimulated adenylate cyclase activity was assessed in myocardial membranes from Fischer 344 rats of 3, 12, and 24 months of age. Basal, as well as F − , GTP − , and hormone-stimulated adenylate cyclase activity was decreased by 20–30% with age. The K m of the enzyme for ATP was not found to be statistically different for any age group studied. These data support the hypothesis that the diminished responsiveness seen in senescence is a result of an alteration in either the catalytic subunit or the coupling protein (N) of the adenylate cyclase complex.
Geochemical processes in the Lake Fryxell Basin (Victoria Land, Antarctica)

Major ion, nutrient, transition metal, and cadmium concentrations are presented for nine meltwater streams flowing into Lake Fryxell, a permanently stratified lake with an anoxic hypolimnion in Taylor Valley, Antarctica. For the major ions, stream compositions are considered in terms of dissolution of marine-derived salts and chemical weathering of local rocks. Although Lake Fryxell has undergone significant evaporative concentration, only calcite, of the simple salts, is predicted to precipitate. Geochemical budgets indicate, however, that large quantities of K, Mg, and SO4 have also been removed from the lake. Reverse weathering may be an important sink for K and Mg, although magnesium removal with calcium carbonate phases is also likely. Assuming constancy of composition over recent geologic time, all of the salts in the Fryxell water column could have been delivered under present flows in about three thousand years (chloride age).
Abstract 4591: Comparison of the inhibitory effects of unmodified and modified combinations of chemopreventive agents on MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Pancreatic cancer is the fourth leading cause of death in the United States with approximately 40,000 estimated deaths in 2010. The objective of our study was to compare the effectiveness of chemopreventive combination regimens of aspirin, curcumin and sulforaphane (ACS) administered in unmodified (free drug) and in modified forms, encapsulated within solid lipid nanoparticles (SLNs), on the MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines. MTS cell proliferation and apoptosis assay studies were conducted on cultured cells. For the MTS assay, upon 75 % confluence, 2.5 × 103 cells for MIA PaCa-2 and 4 × 103 cells for Panc-1 were transferred into each well of 96-well plates. The ACS chemopreventive agents alone or in combination were added to the cells and incubated for 72 h. Absorbance was recorded at 490 nm using an ELISA plate reader. For the apoptosis assay, 3 × 105 cells were cultured in 6-well plates for both Panc-1 and MIA PaCa-2 cell-lines. ACS, individual or combinations, were added and the plates were incubated for 72 h. Cells were analyzed using flow cytometry, measuring the fluorescence emission at 530 nm (FL1) and >575 nm (FL3). IC50 values obtained for the respective unmodified and modified forms of aspirin were (2.05mM/L; 66.08µM/L), curcumin (16.05µM/L; 4.93µM/L) and free sulforaphane at 11.82 µM/L for MIA PaCa-2 cells. Similarly, for Panc-1 cells, the IC50 values for unmodified and modified aspirin were (2.42mM/L; 90.23µM/L), curcumin (24.01 µM/L; 7.5µM/L) respectively and free sulforaphane at 17.81µM/L. For MIA PaCa-2 cell line, unmodified combinations of aspirin (1mM/L) with curcumin (10µM/L) and sulforaphane (5µM/L) showed significant reduction in cell viability of >60% using MTS assay. In comparison, aspirin SLN (25µM/L), curcumin SLN (2.5µM/L) and free sulforaphane (5µM/L) mixtures showed cell viability of >55%. Flow cytometry analysis demonstrated apoptosis of 63% (unmodified) and 50% (modified) for the combinations, at the same concentration ranges as above. For the Panc-1 cell line, treatment with similar concentrations of unmodified and modified SLN combinations showed a >75% and >60% decrease in cell viability (MTS assay) and 63% and 54% induction of apoptosis cells, respectively. Our results demonstrated that the drugs when encapsulated in SLNs at lower concentrations exhibited decreasing cell proliferation and increased induction of apoptosis within the pancreatic cancer cell lines. This data provides compelling evidence of the potential of the SLN carrier system in designing in-vivo studies for the pancreatic cancer chemoprevention. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4591. doi:10.1158/1538-7445.AM2011-4591
Correlates of Black Adolescent Males' Condom Use:

In data from the 1979 National Survey of Younger Men, Black adolescent males reported a somewhat lower rate of condom use than did White males at first intercourse. The race difference in condom use was evident only among those becoming sexually active at age 13 years or younger, and when the partner was a steady girlfriend. Black males showed a higher rate of condom use than did White males at most recent intercourse.
Continuous tissue pH monitoring in critically ill neonates

Continuous tissue pH was measured using a miniaturized glass electrode in 21 sick term and preterm infants. Tissue pH correlated well with arterial (r=0.87) and capillary pH (r=0.90) during the steady state. However, tpH was lower than arterial pH during hypoperfusion and state of shock. Improvement in tissue perfusion resulted in improvement in tpH and good correlation with arterial pH. The electrode was also sensitive to changes in carbon dioxide tension and administration of buffer. The good correlation with arterial pH and the feasibility of continuous recording of tissue pH makes it a useful instrument for monitoring the acid-base status of critically ill neonates.
In vivo and in vitro regulation of thyroid leukemia inhibitory factor (LIF): marker of hypothyroidism.

Several cytokines regulate thyroid function and may be involved in the pathogenesis of thyroid disorders, including euthyroid sick syndrome. Leukemia inhibitory factor (LIF), a neuroimmune pleiotropic cytokine, was measured to assess its role in hypothalamic-pituitary-thyroid function. Mean circulating serum LIF levels in 10 hypothyroid patients [TSH, 23+/-0.5 mIU/L (mean+/-SEM); free T4, 0.77+/-0.1 ng/dL] was 0.29+/-0.04 ng/mL, 145% higher (P 2 microg/kg x day) was administered, both serum TSH (7.5+/-1.2 mIU/L) and LIF (6.22+/-0.31 ng/mL) were lowered (P < 0.01). Monkey serum LIF levels and log TSH levels also correlated (r = 0.72, P < 0.01). Cultured thyroid carcinoma cells produced LIF (9.2 ng/10(6) cells/48 h). TSH (100 mIU/mL) and interleukin (IL)-6 (10 nmol/L) stimulated in vitro LIF secretion from the cells by 170+/-12% (P < 0.05) and 261+/-8% (P < 0.05), respectively. Dexamethasone (1 micromol/L) inhibited basal LIF concentration by 83% (P < 0.05), whereas TSH and IL-6 stimulated LIF by 52% (P = 0.04) and 42% (P = 0.03), respectively. However, using Northern blot analysis, we could not observe induction of LIF mRNA by TSH, suggesting that LIF regulation by TSH may be due to stimulation of secretion. The results show that the thyroid gland is a source of LIF production; TSH, IL-6, and glucocorticoid influence thyroid cell LIF expression. The correlation between TSH and LIF suggests that LIF may participate in the physiologic regulation of hypothalamic-pituitary-thyroid function.
Molecular cloning and characterization of a highly conserved chicken cellular nucleic acid binding protein cDNA

Abstract A chicken cellular nucleic acid binding protein (cCNBP) cDNA was isolated from a chicken Con-A-stimulated immune cell library by differential screening. cCNBP is a Cys/Cys–His/Cys zinc finger DNA binding protein of unknown function. The chicken CNBP nucleotide and deduced amino acid sequence showed extraordinary sequence conservation (between 81–98% similarities) when compared to human, mouse and rat CNBP. The CNBP gene was shown to be a single copy and to cross-hybridize to human and mouse genomic DNA. A Northern blot analysis revealed cCNBP to be a constitutively expressed gene in a wide variety of tissues and to be differentially expressed in cultured chicken spleen and bursal cells after mitogen stimulation.
Kinetic Modeling of Receptor-Ligand Binding Applied to Positron Emission Tomographic Studies with Neuroleptic Tracers

Positron emission tomography (PET) with labeled neuroleptics has made possible the study of neurotransmitter-receptor systems in vivo. In this study we investigate the kinetics of the 3,4-dihydroxyphenylethylamine (dopamine) receptor-ligand binding using PET data from a series of experiments in the baboon with the 18F-labeled drugs spiperone, haloperidol, and benperidol. Models used to describe these systems are based on first-order kinetics which applies at high specific activity (low receptor occupancy). The parameters governing the uptake and loss of drug from the brain were found by fitting PET data from regions with little or no receptor concentration (cerebellum) and from experiments in which specific binding was blocked by pretreatment with the drug (+)-butaclamol. Receptor constants were determined by fitting data from receptor-containing structures. Correcting the arterial plasma activities (the model driving function) for the presence of drug metabolites was found to be important in the modeling of these systems.
Counterpoint: Just Being Alive Is Not Good Enough

Although Dr. Scott Grundy assures us that the Adult Treatment Panel III (ATP III) version of the metabolic syndrome is still alive (1), the real question is whether its continued existence provides us with any useful informa-tion. Just being alive is not enough, for as Sportin’ Life points out in Gershwin’s Porgy and Bess , “Methuselah lived 900 years, but who calls it living, when no gal will give in, to him that’s 900 years.” Before addressing the substance of Dr. Grundy’s comments, I must defend myself against his charge that I have limited my critical comments to the ATP III version of the metabolic syndrome. I am not xenophobic, and in a recent editorial addressed what I perceived to be the drawbacks of both the ATP and WHO versions of the metabolic syndrome (2). The most obvious problem for me is the notion that making a positive diagnosis of the metabolic syndrome, compared with a negative one, helps guide clinical decisions. For example, WHO criteria would not lead to a diagnosis of the metabolic syndrome in an apparently healthy, normotensive man, body mass index of 27.8 kg/m2, with fasting plasma glucose and triglyceride (TG) concentrations of 111 mg/dL (6.16 mmol/L) and 185 mg/dL (2.09 mmol/L), respectively, if he had a HDL-cholesterol (HDL-C) concentration of 37 mg/dL (0.96 mmol/L). By implication, this person would not be at increased risk of cardiovascular disease (CVD). On the other hand, given essentially identical findings, another man, with a HDL-C concentration of 33 mg/dL (0.85 mmol/L), has the metabolic syndrome by WHO criteria and is, by definition, at increased CVD risk. Is the CVD risk any different in these 2 men? Would not the clinical approach be similar in both? More of this later, but suffice it to say that this example …
Nonuniform catalyst distribution for inorganic membrane reactors: Theoretical considerations and preparation techniques

Abstract The performance characteristics of an inert membrane reactor with catalyst on the feed side (IMRCF), a catalytic membrane reactor (CMR), and a fixed-bed reactor (FBR) are compared for uniform and Dirac-type catalyst distributions for the case of a first-order reversible reaction under isothermal conditions. It is demonstrated that for all three reactor types, a Dirac delta distribution of catalyst, located at the external surface (feed side) in either the membrane (CMR) or the pellet (IMRCF and FBR) gives superior performance as compared to the uniformly distributed case. In addition, for the IMRCF, the case of an arbitrary number of reactions following arbitrary kinetics under steady-state nonisothermal conditions, with finite external mass and heat transfer resistances for both the pellet and the inert membrane, is considered. It is shown analytically that in the realistic case where the local catalyst loading is bounded, the optimal distribution of catalyst is in general a multiple step function. As the bound increases, the step function approaches a Dirac delta distribution. Novel preparation techniques for supported thin metal composite membranes for IMRCF applications and inorganic membranes with nonuniform distribution of catalyst for CMRs are also described. The first technique employs electroless plating along with osmotic pressure to yield supported thin membranes of controlled microstructure, porosity and thickness. The preparation of silver films deposited on commercial alumina membrane is presented as an example. Heat treatment in oxygen demonstrates that Ag/alumina membranes thus prepared are thermally more stable than similar membranes prepared using standard electroless plating procedures. In the second technique, using sequential slip-casting of inert and platinum impregnated alumina sols, precise control of the catalyst layer thickness and location within the alumina membrane is obtained.
Quantifying Exchange Rates in Chemical Exchange Saturation Transfer Agents Using the Saturation Time and Saturation Power Dependencies of the Magnetization Transfer Effect on the Magnetic Resonance Imaging Signal (QUEST and QUESP): pH Calibration for Poly-l-Lysine and a Starburst Dendrimer

The ability to measure proton exchange rates in tissue using MRI would be very useful for quantitative assessment of magnetization transfer properties, both in conventional MT imaging and in the more recent chemical exchange saturation transfer (CEST) approach. CEST is a new MR contrast mechanism that depends on several factors, including the exchange rate of labile protons in the agent in a pH-dependent manner. Two new methods to monitor local exchange rate based on CEST are introduced. The two MRI-compatible approaches to measure exchange are quantifying exchange using saturation time (QUEST) dependence and quantifying exchange using saturation power (QUESP) dependence. These techniques were applied to poly-L-lysine (PLL) and a generation-5 polyamidoamine dendrimer (SPD-5) to measure the pH dependence of amide proton exchange rates in the physiologic range. Data were fit both to an analytical expression and to numerical solutions to the Bloch equations. Results were validated by comparison with exchange rates determined by two established spectroscopic methods. The exchange rates determined using the four methods were pooled for the pH-calibration curve of the agents consisting of contributions from spontaneous (k0) acid catalyzed (ka), and base catalyzed (kb) exchange rate constants. These constants were k0 = 68.9 Hz, ka = 1.21 Hz, kb = 1.92 x 10(9) Hz, and k0 = 106.4 Hz, ka = 25.8 Hz, kb = 5.45 x 10(8) Hz for PLL and SPD-5, respectively, showing the expected predominance of base-catalyzed exchange for these amide protons.