cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural Determinants for the Selective Anti-HIV-1 Activity of the All-β Alternative Conformer of XCL1

ABSTRACT HIV-1 replication is regulated in vivo by a complex network of cytokines and chemokines. XCL1/lymphotactin, a unique metamorphic chemokine, was recently identified as a broad-spectrum endogenous HIV-1 inhibitor that blocks viral entry via direct interaction with the gp120 envelope glycoprotein. HIV-1 inhibition by XCL1 requires access to the alternative all-β conformation, which interacts with glycosaminoglycans (GAGs) but not with the specific XCL1 receptor, XCR1. To investigate the structural determinants of the HIV-inhibitory function of XCL1, we performed a detailed structure-function analysis of a stabilized all-β variant, XCL1 W55D. Individual alanine substitutions of two basic residues within the 40s9 loop, K42 and R43, abrogated the ability of XCL1 to bind to the viral envelope and block HIV-1 infection; moreover, a loss of HIV-inhibitory function, albeit less marked, was seen upon individual mutation of three additional basic residues: R18, R35, and K46. In contrast, mutation of K42 to arginine did not cause any loss of function, suggesting that the interaction with gp120 is primarily electrostatic in nature. Strikingly, four of these five residues cluster to form a large (∼350 A 2 ) positively charged surface in the all-β XCL1 conformation, whereas they are dissociated in the classic chemokine fold, which is inactive against HIV-1, providing a structural basis for the selective antiviral activity of the alternatively folded XCL1. Furthermore, we observed that changes to the N-terminal domain, which is proximal to the cluster of putative HIV-1 gp120-interacting residues, also affect the antiviral activity of XCL1. Interestingly, the complement of residues involved in HIV-1 blockade is partially overlapping, but distinct from those involved in the GAG-binding function of XCL1. These data identify key structural determinants of anti-HIV activity in XCL1, providing new templates for the development of HIV-1 entry inhibitors. IMPORTANCE The host immune system controls HIV-1 infection through a wide array of inhibitory responses, including the induction of cytotoxic effector cells and the secretion of noncytolytic soluble antiviral factors such as cytokines and chemokines. We recently identified XCL1/lymphotactin, a chemokine primarily produced by CD8 + T cells, as a novel endogenous factor with broad anti-HIV activity. Strikingly, only one of the two conformations that XCL1 can adopt in solution, the alternative all-β fold, mediates antiviral activity. At variance with the classic HIV-inhibitory chemokines such as CCL5/RANTES, XCL1 acts via direct interaction with the external viral envelope glycoprotein, gp120. Here, we identify the interactive surface of XCL1 that is implicated in binding to the HIV-1 envelope and HIV-1 inhibition, providing a structural basis to explain why only the all-β XCL1 conformer is effective against HIV-1. Our findings may be useful in guiding the rational design of new inhibitors of HIV-1 entry.
From teachers to testers: How parents talk to novice and expert children in a natural history museum

Informed by literature on childhood expertise in high-interest topics and parent–child conversation in museum settings, this study explored how children's level of dinosaur expertise influences family learning opportunities in a natural history museum. Interviews identified children with high and low dinosaur knowledge and assigned them to expert and novice groups. Parent surveys revealed that expert children were more likely to have home environments where family members shared interests in dinosaurs and provided a variety of dinosaur learning resources. Analysis of family conversations demonstrated that parents with novice children more actively engaged them in learning conversations than parents with expert children. The implications of this shift in parental engagement are considered in terms of interest and knowledge development in informal settings, highlighting how islands of expertise might facilitate and in some cases hinder learning through shared family activity. © 2007 Wiley Periodicals, Inc. Sci Ed91:783–804, 2007
An Application-Specific Protocol/Network for Massive Parallel Testing

In an effort to substantially reduce the relatively high chip testing time, an application specific protocol/network named Test Area Network (TAN) is proposed based on the open standard suggestion for automatic test equipment. TAN architecture speeds up testing manifold and thus reduces the overall test cost significantly. The advantages of the proposed architecture come from the radically new idea of using packet switched network as the mode of communication between test equipment and tens of device under test.
Severe osteoporosis before and after lung transplantation.

Study objective Osteoporosis and/or fractures have been reported as a complication of kidney, heart, liver, bone marrow, and, most recently, lung transplantation (LTx). We measured bone mineral density (BMD) before and after LTx to determine the frequency and severity of preoperative and postoperative osteoporosis. Patients and methods We conducted a cross-sectional study of BMD in 100 patients with various diagnoses before (n=55) and after (n=45) LTx. Results Age-matched mean spine and femoral BMDs were severely depressed before and after LTx placing 45% of the pre-LTx and 73% of the post-LTx patients at or below the fracture threshold (2 SDs below the mean). As expected, patients with cystic fibrosis had lower (p Conclusions Osteoporosis appears to be widespread in patients with end-stage respiratory failure before LTx and LTx, while often life-saving, has an adverse impact on BMD. As patients live longer after LTx, osteoporosis-related fractures may compromise quality of life by causing pain and debilitation.
Cyclic 3',5'-AMP phosphodiesterase activity during cyclic AMP-induced differentiation of neuroblastoma cells in culture.

SummaryThe cyclic AMP phosphodiesterase (PDE) activity markedly increased in morphologically “differentiated” mouse neuroblastoma cells induced by dibutyryl cyclic AMP, prostaglandin E1 (stimulator of adenylate cyclase) and 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (RO 20-1724, an inhibitor of PDE). Initially, RO 20-1724 decreased the PDE activity by about 50% of control, but later it increased the PDE activity. All of the above agents are known to increase the endogenous level of cyclic AMP, and therefore, in the differentiated cells, a high level of PDE correlated well with a high level of cyclic AMP. X-Irradiation which causes morphological “differentiation” similar to that by dibutyryl cyclic AMP did not increase the PDE activity. Sodium butyrate, 3′,5′-cyclic AMP, 5′-AMP and theophylline which inhibit cell division without causing morphological differentiation did not affect significantly the basal level of PDE. Cycloheximide markedly reduced the PDE activity, whereas actinomycin D did not. A wo...
A patient with anaphylactoid hypersensitivity to intravenous cyclosporine and subcutaneous phytonadione (vitamin K(1)).

A patient with anaphylactoid hypersensitivity to intravenous cyclosporine and subcutaneous phytonadione (vitamin K 1 )
Career Preferences of Early Adolescents: Age and Sex Differences

Motivating early adolescents in classrooms as well as counseling them in career decision making suggest that educators need a better understanding of developing career preferences among early adolescents. When the scores of males and females were compared across ages on eight career preference scales, several patterns emerged. Most career areas suffer a decline in interest among both boys and girls in the initial years of early adolescence. However, in five of eight areas, boys' scores showed a significant rebound after age thirteen reflecting stronger interest in high technology careers than did girls'. Girls, on the other hand, showed increasing interest in traditional areas such as service and organization. Both sexes indulged in dreams of trying careers in arts and entertainment.
Review: mammography reduces breast cancer mortality rates.

Source Citation Humphrey LL, Helfand M, Chan BK, Woolf SH. Breast cancer screening: a summary of the evidence for the U.S. Preventive Services Task Force. Ann Intern Med. 2002;137:347-60. 12204020 ...
Potential opportunity cost of neglecting to annually reassess Medicare Part D standalone prescription drug plan offerings: the price of contentment?

Abstract Objectives To determine the (1) potential cost difference (opportunity cost [OC]) to Medicare-eligible beneficiaries enrolled in the lowest-cost standalone prescription drug plan (PDP) in 2007 between the cost of such plan in 2008 and the lowest-cost plan in 2008 and the (2) percentage of PDPs with the lowest estimated annual cost (EAC) in both 2007 and 2008. Design Descriptive exploratory study. Setting United States during 2007 and 2008. Patients 50 patients were randomly selected from a database of Medicare-eligible beneficiaries. Intervention Pharmacy claims records for each study patient were obtained during the period January 1 to June 30, 2007. Patient medication profiles were generated using these data and entered into the Medicare Plan Finder Tool ( www.medicare.gov ) to obtain the EAC of each PDP from 2007 and 2008 in all 34 Medicare Part D regions. Main outcome measures The 2008 EAC of the lowest-cost PDP from 2007 was recorded. OC was determined by subtracting the 2008 EAC of the lowest-cost PDP in 2008 from the 2008 EAC of the lowest-cost PDP in 2007 for each patient in each region. The percentage of PDPs that had the lowest EAC in both 2007 and 2008 was recorded. Results The 2008 EACs of the lowest-cost PDPs from 2007 were significantly higher ( P Conclusion Medicare beneficiaries should reevaluate PDP offerings annually during the open enrollment period; failure to do so may increase avoidable out-of-pocket costs.
Effect of buffer addition to high grain total mixed rations on rumen pH, feed intake, milk production, and milk composition

Abstract Lactating Holstein cows (n = 56) were fed high grain TMR in three feeding experiments to determine the effects of two rumen buffers on feed intake, milk production, and milk composition. The basal diet in Experiment 1 was 40% grass silage, 12% whole cottonseed, and 48% concentrate with treatments of 1) control (no added buffer), 2) 1.5% of dietary DM as Alkaten ® , and 3) 1.5% of dietary DM as Rumen 8 ® . In Experiment 2, diets consisted of 12% corn and sunflower silage, 20% whole cottonseed, and 68% concentrate with treatments as in Experiment 1. The diets in Experiment 3 were identical to those in Experiment 2, except that buffers were increased to 2.2% of dietary DM. The DMI was greater for cows fed buffered diets than control diets in Experiments 2 and 3. Milk production was unaffected by treatment. Milk fat percentage was unaffected by diet in Experiment 1 and averaged 3.8%. Milk fat depression was alleviated for cows fed buffered diets in Experiments 2 and 3. No differences in rumen fluid pH or molar percentage of VFA were significant among treatments.
Intertidal distribution, population dynamics and production of the amphipod Uhlorchestia spartinophila in a Georgia, USA, salt marsh

The talitrid amphipod Uhlorchestia spartinophila Bousfield and Heard occurs in close association with the smooth cordgrass Spartina alterniflora Loisel in salt marshes along the U.S. Atlantic coast. In order to assess its potential as a prey resource for secondary consumers, we followed the population and production dynamics of this amphipod from 3 November 1990 to 2 October 1991 in a salt marsh on Sapelo Island, Georgia. Semimonthly samples were taken along an intertidal transect, which extended from a vegetated creekbank levee landward 140 m to a site near the upland edge of the marsh. Amphipod densities ranged from 9 to 826 indm-2 and were greatest in the levee and high marsh habitats at opposite ends of the transect. The highest densities occurred in March to May and the lowest in November and December. Specific growth rates, which ranged from 0.001 to 0.024 mm mm-1 d-1 length and 0.003 to 0.068 mg mg-1 d-1 AFDW (ash-free dry weight), were least in winter and decreased with increasing amphipod size. Although some reproduction occurred year-round, most of the population's reproductive output was from January to May, when adults had the greatest size-specific mass. Sex ratio usually favored females, which were larger than males. Minimum adult female size was 5.4 mm total length (TL). Broods included from 1 to 28 eggs or young and increased with increasing body size, averaging 7.4 young for an average-size female of 7.6 mm TL. Annual production, which ranged from 0.769 to 1.444 g AFDW m-2, was least in the low marsh and greatest in the levee habitat. Production:biomass ratios were 15.4 to 17.3 in different habitats. Such high turnover rates, together with the population's broad intertidal distribution, suggest a greater contribution to trophic dynamics than is implied by the relatively low standing stock biomass of U. spartinophila in this marsh system.
High Cycle Fatigue Life-Prediction for Lead-Free Interconnects Under Simultaneous High Temperature and Vibration

Current trends in the automotive industry warrant a variety of electronics for improved control, safety, efficiency and entertainment. Many of these electronic systems like engine control units, variable valve sensor, crankshaft-camshaft sensors are located under-hood. Electronics installed in under-hood applications are subjected simultaneously to mechanical vibrations and thermal loads. Typical failure modes caused by vibration induced high cycle fatigue include solder fatigue, copper trace or lead fracture. The solder interconnects accrue damage much faster when vibrated at elevated temperatures. Industry migration to lead-free solders has resulted in a proliferation of a wide variety of solder alloy compositions. Presently, the literature on mechanical behavior of lead-free alloys under simultaneous harsh environment of high-temperature vibration is sparse. In this paper, the reduction in stiffness of the PCB with temperature has been demonstrated by measuring the shift in natural frequencies. The test vehicle consisting of a variety of lead-free SAC305 daisy chain components including BGA, QFP, SOP and TSOPs has been tested to failure by subjecting it to two elevated temperatures and harmonic vibrations at the corresponding first natural frequency. The test matrix includes three test temperatures of 25C, 75C and 125C and simple harmonic vibration amplitude of 10G which are values typical in automotive testing. PCB deflection has been shown to increase with increase in temperature. The full field strain has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. Material properties of the PCB at test temperatures have been measured using tensile tests and dynamic mechanical analysis. FE simulation using global-local finite element models is thus correlated with the system characteristics such as modal shapes, natural frequencies and displacement amplitudes for every temperature. The solder level stresses have been extracted from the sub-models. Stress amplitude versus cycles to failure curves are obtained at all the three test temperatures. A comparison of failure modes for different surface mount packages at elevated test temperatures and vibration has been presented in this study.Copyright © 2013 by ASME
Information management: a key to corporate productivity

U.S. Business today faces severe tests in both national and international markets due to intense competition from foreign companies. Consequently, widespread attention is being given to the problem of increasing the productivity and long-term profitability of U.S. business. Productivity is used here to refer the efficiency and effectiveness of the conversion of resources to output goods and services.
Once-daily gentamicin dosing in newborn infants.

Objective. We developed a simplified gentamicin dosing protocol for all neonates using a loading dose and once-daily dosing that would have an equal or lower incidence of toxicity and an equal or improved effectiveness compared with a regimen with no loading dose that included use of divided daily dosing. Methods. All neonatal intensive care unit patients with a postnatal age ≤7 days and started on gentamicin therapy at the discretion of the attending neonatologist were evaluated in this comparative cohort study. All peak and trough serum drug levels (SDL), pertinent demographic data, and markers of potential nephrotoxicity, ototoxicity, and cure were tracked prospectively during 132 consecutive, nonrandomized courses of therapy on a new gentamicin protocol. These were compared with data retrieved retrospectively throughout 103 consecutive, nonrandomized courses of therapy in a control group. Results. Initial measured peak SDL were higher (7.8 ± 1.1 μg/mL vs 6.1 ± 1.0 μg/mL) and trough SDL were lower (0.9 ± 0.2 μg/mL vs 2.7 ± 0.6 μg/mL) in the protocol term subset, compared with the control term subset (gestational age, ≥37 weeks; weight, ≥2500 g). One hundred percent of the initial and maintenance peak SDL in term protocol neonates were 5 to 12 μg/mL; compared with 84% of the initial and 61% of maintenance peak SDL in the term control group. One hundred percent of the initial and maintenance trough SDL were in the desired range of 1500 g) in the protocol compared with the control group. The very low birth weight (weight Conclusion. A loading dose followed by once-daily dosing was shown to result in SDL in the safe and therapeutic range in all term neonates in this study. In low birth weight neonates, this regimen resulted in peak and trough SDL throughout therapy that were similar to those observed in the control group. Delaying the initiation of maintenance once-daily dosing until 36 to 48 hours after the loading dose would be expected to result in a higher incidence of initial trough SDL in target range for very low birth weight neonates.
The Library–Information Technology Partnership: Challenges and Solutions

The Klarchek Information Commons is a collaboration between Loyola University Libraries and Information Technology Services (ITS). The Information Commons has been open almost 2 years and was in th...
Sampling and surface reconstruction with adaptive-size meshes

This paper presents a new approach to sampling and surface reconstruction which uses the physically based models. We introduce adaptive-size meshes which automatically update the size of the meshes as the distance between the nodes changes. We have implemented the adaptive-size algorithm to the following three applications: (1) Sampling of the intensity data. (2) Surface reconstruction of the range data. (3) Surface reconstruction of the 3-D computed tomography left ventricle data. The LV data was acquired by the 3-D computed tomography (CT) scanner. It was provided by Dr. Eric Hoffman at University of Pennsylvania Medical school and consists of 16 volumetric (128 X 128 X 118) images taken through the heart cycle.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Human Hypersensitivity Angiitis, An Immune Complex Disease

Human hypersensitivity angiitis is an immune complex disease in which patients present with palpable purpuric lesions of the skin and may often have multiple organ involvement. The antigen may be derived from an infectious organism such as the hepatitis virus, streptococcus, or a drug, and complexes with antibody. Under circumstances of vascular turbulence or vessel wall dilatation this complex may become fixed, activating the complement sequence with elaboration of chemotactic factors for neutrophils. These cells release lysosomal enzymes resulting in vessel wall destruction. Red blood cells leak into the tissue producing purpura and the inflammatory infiltrate accounts for the palpability. Although many patients have skin lesions only, others may have involvement of joints, gastrointestinal tract, kidneys, and even the lungs. The central question in the pathogenesis of this disease is why the immune complex is so selective in its site of deposition. Part of the reason must be related to the lattice formation of a particular complex, while other reasons are related to host factors of altered vascular permeability, integrity of clearance mechanisms or even a genetically determined defect of the phagocytic system.
Toward a Causal Interpretation from Observational Data: A New Bayesian Networks Method for Structural Models with Latent Variables

Because a fundamental attribute of a good theory is causality, the information systems (IS) literature has strived to infer causality from empirical data, typically seeking causal interpretations from longitudinal, experimental, and panel data that include time precedence. However, such data are not always obtainable and observational (cross-sectional, nonexperimental) data are often the only data available. To infer causality from observational data that are common in empirical IS research, this study develops a new data analysis method that integrates the Bayesian networks (BN) and structural equation modeling (SEM) literatures.Similar to SEM techniques (e.g., LISREL and PLS), the proposed Bayesian networks for latent variables (BN-LV) method tests both the measurement model and the structural model. The method operates in two stages: First, it inductively identifies the most likely LVs from measurement items without prespecifying a measurement model. Second, it compares all the possible structural models among the identified LVs in an exploratory (automated) fashion and it discovers the most likely causal structure. By exploring the causal structural model that is not restricted to linear relationships, BN-LV contributes to the empirical IS literature by overcoming three SEM limitations (Lee, B., A. Barua, A. B. Whinston. 1997. Discovery and representation of causal relationships in MIS research: A methodological framework. MIS Quart. 21(1) 109–136) — lack of causality inference, restrictive model structure, and lack of nonlinearities. Moreover, BN-LV extends the BN literature by (1) overcoming the problem of latent variable identification using observed (raw) measurement items as the only inputs, and (2) enabling the use of ordinal and discrete (Likert-type) data, which are commonly used in empirical IS studies.The BN-LV method is first illustrated and tested with actual empirical data to demonstrate how it can help reconcile competing hypotheses in terms of the direction of causality in a structural model. Second, we conduct a comprehensive simulation study to demonstrate the effectiveness of BN-LV compared to existing techniques in the SEM and BN literatures. The advantages of BN-LV in terms of measurement model construction and structural model discovery are discussed.
Latitude and Longitude of the Past: Place, Negritude and French Caribbean Identity in Aimé Césaire's Poetry

Cesaire is one of the greatest French poets of the 20th century and his oeuvre has been studied by many scholars in its slightest recesses. In what way could a geographic analysis lead to a better understanding of Cesaire’s poetry and his process of identity-making? Actually, the geographic dimension of his writings has not really been analyzed, though it is one of the main backdrops of his poetry. Cesaire invents his own geography of imagination as he claims it. What are the frames of his map of the word for personal use? Cesaire’s purpose is to find again his latitude and longitude lost in the wake of the slave ships. To exist, an uprooted person, as Cesaire was, has to write a new relationship with the Earth according to the philosophy of geography developed by Eric Dardel. The author of this paper analyzes the influence of Cesaire’s poetry and his vision of the world in the process of identity-making. Cesaire’s poetry is first a personal revolt against colonial domination. But thanks to the strength of his writings, he overcame his inner wound to build a new Caribbean identity.
Properties of Spinal Motoneurons and Interneurons in the Adult Turtle: Provisional Classification by Cluster Analysis

The purpose of the present study was to compare, in motoneurons (MNs) vs. interneurons (INs), selected passive, transitional, and active (firing) properties, as recorded in slices of lumbosacral spinal cord (SC) taken from the adult turtle. The cells were provisionally classified on the basis of (1) the presence (in selected INs) or absence (MNs and other INs) of spontaneous discharge, (2) a cluster analysis of selected properties of the nonspontaneously firing cells, (3) a comparison to previous data on turtle MNs and INs, and (4) a qualitative comparison of the results with those reported for other vertebrate species (lamprey, cat). The provisional nomenclature accommodated properties appropriate for solely MNs (Main MN group) vs. nonspontaneously firing INs (Main IN-N) vs. spontaneously firing INs (IN-S) and for neurons with two degrees of intermediacy between the Main MN and the Main IN-N groups (Overlap MN, Overlap MN/IN). Morphological reconstructions of additional cells, which had been injected with biocytin during the electrophysiological tests, were shown to provide clear-cut support for the provisional classification procedure. The values for the measured parameters in the 96 tested cells covered the spectrum reported previously across adult vertebrate species and were robust in measurements made on different SC slices up to 5 days after their removal from the host animal. The interspecies comparisons permitted the predictions that (1) our Main MN and Overlap MN cells would be analogous to two MN types that innervate fast-twitch and slow-twitch skeletomotor muscle fibers, respectively, in the cat, and (2) the MNs in our Overlap MN/IN group probably innervate slow (nontwitch, tonic) muscle fibers whose presence has recently been established in the turtle hindlimb. In summary, the results bring out the utility of the SC slice preparation of the turtle for study of spinal motor mechanisms in adult tetrapod vertebrates, particularly as an adjunct to the in vivo cat, because of the ease with which robust measurements can be made of the active properties of both MNs and INs.
COMPLEX TOPOLOGY IN THE HIGHWAY NETWORK OF HUNGARY, 1990 AND 1998

Abstract This paper presents a technique for abstracting features of a highway network as complex topology on a planar graph. Official highway maps of Hungary provide the data. Concepts of functional hierarchy and polycentric cities are the basis for classification of nodes, impediments, and link segments. Classes are assigned values to create a model that can be used to compare links and evaluate infrastructure changes. Complex topology facilitates policy decisions in countries that rely on a variety of road classes. The technique provides policy-makers with a tool for evaluating the competing priorities of international, national, and regional interests.
Soft X-Ray Multilayers Produced By Sputtering And Molecular Beam Epitaxy (MBE): Substrate And Interfacial Roughness

Interfacial and substrate roughness can greatly reduce the performance of multilayer optical coatings for soft x-rays. Due to the short wavelength of soft x-ray light, multilayers with roughness on the order of a few Angstroms are required to achieve adequate performance. In the present work, roughness measurements have been made on uncoated silicon wafers and float glass using a WYKO TOPO-3D phase shifting interferometer. The silicon wafers are found to be slightly smoother than the float glass. The effects of different cleaning methods and of the deposition of silicon "buffer layers", on substrate roughness also have been examined. An acid cleaning method is presented that gives more consistent results than detergent cleaning. Healing of the roughness due to sputtered silicon buffer layers was not observed on the length scale probed by the WYKO. Sputtered multilayers have been characterized with both the WYKO interferometer and low-angle x-ray diffraction to yield information about the roughness of the top surface and of the interfaces of the multilayer. Simulations based on these measurements show the need for extremely smooth layers for certain mirrors. Preliminary results on film growth in our recently acquired Molecular Beam Epitaxy (MBE) system are also presented. Although a MBE acid cleaning method greatly increases the roughness of the substrates, Reflection High Energy Electron Diffraction (RHEED) shows this cleaning method is not necessary to achieve epitaxial growth.
Embryonal carcinoma stem cells lack a function required for virus replication

Embryonal carcinoma (EC) stem cells are thought to be equivalent to the ectoderm of the preimplantation mouse embryo because they share morphological, biochemical and antigenic properties1,2. These near diploid EC cells can be induced to differentiate into cell types of all three germ layers1,2. They also can take part in normal differentiation and contribute cells to many tissues in chimaeric mice derived from preimplantation mouse embryos injected with them3. The ability to restrict the growth of certain viruses is a distinguishing characteristic of EC cells4–8, but it is intriguing that this restriction disappears after differentiation. The ability of EC cells to block totally productive infection by the highly infectious and oncogenic Moloney strain of murine leukaemia virus (M-MuLV) is remarkable, as virtually all other murine cells are permissive to the growth of this virus. Teich et al.7 suggested that replication of M-MuLV in EC cells is blocked at some point after integration of pro viral DNA into the cell's genome. Here I enquire into the dominant or recessive nature of the restriction, that is, do EC cells show transdominant inhibition of virus replication analogous to that imposed by interferon or the mouse Fv-l locus, or is the block to MuLV replication due to the lack of something in the EC cell? This report shows that the restriction of M-MuLV in EC cells can be overcome by fusion with permissive cells. The resulting complemented growth of M-MuLV in EC/permissive cell heterokaryons indicates that the restriction over M-MuLV is a recessive trait of EC cells and, therefore, defines a hitherto unknown host function that is vital to virus growth but missing in EC cells.
γ Chain-associated Cytokine Receptors Signal through Distinct Transducing Factors

Abstract The IL-2, IL-4, and IL-7 signaling pathways have been shown to utilize shared components. The receptors for these cytokines are composed of ligand-specific binding chains that associate with a shared signaling subunit, the common γ (γc) chain. In addition, IL-2, IL-4, and IL-7 induce activation of a common set of nonreceptor tyrosine kinases, Jak-1 and Jak-3. We have further investigated the signaling events induced by these cytokines and find that the γc-associated receptors activate distinct signal transducing factors (STFs). In addition, we show that a 94-kDa STAT-related protein (p94) is activated in response to IL-2 and IL-7, but not IL-4. These data indicate that IL-2, IL-4, and IL-7 activate distinct signaling molecules which might be differentially recruited to the receptor complex by the ligand-specific units of the IL-2, IL-4, and IL-7 receptors.
Berkson's bias revisited.

Abstract When used in a loose manner to indicate distortive effects on associations among hospitalized patients, the term Berkson's bias denotes a special case of Simpson's paradox. If, however, Berkson's independence assumption is introduced, Berkson's bias affects only the “selected” subjects and not those “left behind” and tends to decrease the odds-ratio. Generally speaking, the model is valid not only for case-control studies but also for prospective and other investigations. By introducing a time dimension the model allows for the study of changes over time in Berkson's bias.
Selective Bromination of Aromatic Ethers with Pyridinium Hydrobromide Perbromide

Abstract In aqueous polar solvents, various aromatic ethers were selectively brominated using pyridinium hydrobromide perbromide.
On the superlinear convergence of the variable metric proximal point algorithm using Broyden and BFGS matrix secant updating

In previous work, the authors provided a foundation for the theory of variable metric proximal point algorithms in Hilbert space. In that work conditions are developed for global, linear, and super–linear convergence. This paper focuses attention on two matrix secant updating strategies for the finite dimensional case. These are the Broyden and BFGS updates. The BFGS update is considered for application in the symmetric case, e.g., convex programming applications, while the Broyden update can be applied to general monotone operators. Subject to the linear convergence of the iterates and a quadratic growth condition on the inverse of the operator at the solution, super–linear convergence of the iterates is established for both updates. These results are applied to show that the Chen–Fukushima variable metric proximal point algorithm is super–linearly convergent when implemented with the BFGS update.
Snap Bean Texture Softening and Pectin Solubilization Caused by the Presence of Salt during Cooking

Special procedures were used to separate the effects on softening and pectin solubilization of the presence of salt during cooking from the effects of salt apart from cooking. The effects of the presence of salt during cooking, calculated with respect to corresponding distilled water cooked beans, were greater with processing conditions of lower blanch temperature and shorter cook times, consequently they were greater with higher canned bean firmness and lower liquor pectin. Neither softening nor pectin solubilization had a significant relation to the reduction in pH induced by NaCl. The softening due to salts was seen with NaCl, KCl, and, to a lesser extent, with CaCl2, and it may be the result of accelerated degradation of pectins.
A material dissolution of the problem of induction

In a formal theory of induction, inductive inferences are licensed by universal schemas. In a material theory of induction, inductive inferences are licensed by facts. With this change in the conception of the nature of induction, I argue that the celebrated “problem of induction” can no longer be set up and is thereby dissolved. Attempts to recreate the problem in the material theory of induction fail. They require relations of inductive support to conform to an unsustainable, hierarchical empiricism.
Quantitative measurement of hydroxyl radical induced DNA double-strand breaks and the effect of N-acetyl-l-cysteine

Reactive oxygen species, such as hydroxyl or superoxide radicals, can be generated by exogenous agents as well as from normal cellular metabolism. Those radicals are known to induce various lesions in DNA, including strand breaks and base modifications. These lesions have been implicated in a variety of diseases such as cancer, arteriosclerosis, arthritis, neurodegenerative disorders and others. To assess these oxidative DNA damages and to evaluate the effects of the antioxidant N-acetyl-l-cysteine (NAC), atomic force microscopy (AFM) was used to image DNA molecules exposed to hydroxyl radicals generated via Fenton chemistry. AFM images showed that the circular DNA molecules became linear after incubation with hydroxyl radicals, indicating the development of double-strand breaks. The occurrence of the double-strand breaks was found to depend on the concentration of the hydroxyl radicals and the duration of the reaction. Under the conditions of the experiments, NAC was found to exacerbate the free radical-induced DNA damage.
Radiological Benchmarks for Effects on Aquatic Biota at the Oak Ridge Reservation

Radiological benchmarks for aquatic biota were developed for use at the U.S. Department of Energy's Oak Ridge Reservation as screening values to determine the spatial extent of potential ecological effects and to identify the need for additional site-specific investigation. The Point Source Dose Distribution approach was used to calculate water and sediment activities for selected radionuclides that result in a total dose rate to small and large fish of 1 Rad d−1, which is the National Council on Radiation Protection and Measurements recommended acceptable dose rate to natural populations of aquatic biota. These screening values incorporate internal and external exposures from parent isotopes and all short-lived daughter products. They also include exposures from all major alpha, beta, and gamma emissions for each isotope. Unlike exposures to chemicals, exposures to radionuclides are expressed as the dose rate received by the organism. Dose rates that account for the biological effects to the organism are...
Family correlates of internalizing and externalizing behavior among boys and girls enrolled in Head Start

This study examines the rate of internalizing and externalizing behavior and whether or not family factors influence internalizing and externalizing behavior differently depending on child gender. Sixty‐three Head Start parent–child dyads participated in this study. Rates of externalizing behavior at home for males and females were consistent with other published studies (18.2% and 22%, respectively) Only 4.5% of the males and 24% of the females were categorized as having clinically significant internalizing difficulties at home. Teacher reports of internalizing behavior for males and females were much higher than parent reports (18.2% and 22%, respectively). Depression contributed unique variance and was the only significant predictor of girls’ externalizing behavior, and approached significance as a predictor of boys’ externalizing behavior. Dissatisfaction with social support contributed unique variance and was the only significant predictor of girls’ internalizing behavior. Family factors were not cor...
A spectroscopic study of equilibrium in nitrogen arcs

Abstract Nitrogen arc measurements of the intensity of the 4915 A-4935 A NI doublet and of the 3995 A NII line show that local thermodynamic equilibrium cannot be assumed in nitrogen arcs at electron densities below 1×1017 cm-3. Below this point, the results suggest that gas and electron temperatures differ significantly and that ground states are overpopulated with respect to upper electronically excited states.
Rare infundibular tumors: clinical presentation, imaging findings, and the role of endoscopic endonasal surgery in their management.

Background The spectrum of infundibular lesions is broad and distinct from sellar pathologies. In many cases, histology is needed to establish the correct diagnosis and determine the treatment approach. Methods Medical files of eight patients with distinct infundibular tumors were reviewed. Histopathologically confirmed diagnosis included three pituicytomas, three granular cell tumors, and two pilocytic astrocytomas. Results Patients shared similar imaging findings and clinical symptoms, including visual impairment (n ¼ 5), hypopituitarism (n ¼ 4), and headache (n ¼ 4); one patient presented with disseminated disease and symptoms from spinal metastases. All the pituicytomas,twogranularcelltumors,andone infundibularpilocytic astrocytomacase underwent endoscopic endonasal surgery; gross total resection was achieved in five patients, three developed postoperative diabetes insipidus, and two developed hypopituitarism. No recurrences were observed. One granular cell tumor patient was treated with gamma-knife radiosurgery after stereotactic biopsy; the tumor remained stable in size for over 9 years. The infundibular pilocytic astrocytoma patient who presented with spinal metastases received radiotherapy and systemic chemotherapy. The overall mean follow-up period was 25.1 months. Conclusion Infundibular tumors are rare entities that represent a diagnostic challenge. Histopathological examination is essential for definitive diagnosis. Surgery, radiation therapy, and chemotherapy all have a role in the management of these tumors.
AIDS and STDs In Africa: Bridging the Gap between Traditional Healing and Modem Medicine

AIDS and STDs In Africa: Bridging the Gap between Traditional Healing and Modem Medicine. EDWARD C. GREEN. Boulder, CO and Oxford: Westvlew Press, 1994. xi + 276 pp. photographs, tables, bibliography, Index.
The Role of Money in Economic Growth

The purpose of this paper is to question the meaningfulness of recent monetary growth theory based on money as a "factor of production," such as proposed by Levhari and Patinkin," Johnson,2 and Friedman,3 and from a positive viewpoint, to restate the mechanism through which money does affect economic growth. The foundation of the analysis is the proposition that money has two functions: (1) providing certain types of efficiency and utility and (2) providing the basis for credit creation. These functions are associated with quite different mechanisms, imply potentially different sets of assets as money, and differ in importance. The "new view" in monetary growth theory is associated with the first function, the traditional or "old-fashioned view" with the second. In the first section of this paper we will develop these concepts of the two functions of money by reviewing the nature of a barter economy and how it is altered by the introduction of a medium of exchange. In Section II we will argue that monetary growth theory based on the first function of money as a factor of production and source of utility suffers from three flaws. First, it is a misleading theory because it is too narrowly construed. There are at least three important "financial breakthroughs" that occur in the process of economic growth, all of which provide efficiency and utility. They include the establishment of a credit system, the establishment of intermediation, and the establishment of a medium of exchange. The new view focuses only on the latter. For accuracy and consistency, all three should be included in analysis. If an economy could choose only one of the three for its development strategy, it is by no means obvious on efficiency grounds which it should choose.
Experimental measurements and theoretical predictions for the MOCVD of gallium arsenide using a barrel-type reactor

Abstract A critical comparison has been made between theoretical predictions and experimental measurements regarding the deposition of gallium arsenide wafers by MOCVD in a barrel type reactor. The theoretical predictions were based on a previously published mathematical model in which allowance was made for forced and natural convection, system geometry, thermal diffusion and homogeneous gas phase decomposition. The theoretically predicted deposition rates were always within 50% of the measurements, but often the discrepancy was less than 15%. The model was able to predict experimentally observed trends, regarding the effect of the carrier gas flow rate, system pressure and susceptor temperature. Furthermore, the spatial distribution of the deposition rate was also well predicted. These results suggest that, at least for the system considered, hetrogeneous surface kinetics did not play an important role in determining the overall deposition rate.
“I See My Mother’s Face”: Student nurse experiences caring for cancer patients

Abstract Purpose With the numbers of cancer diagnoses increasing annually and the aging of the global citizenry, it is certain that more nurses with expert competencies in cancer care will be needed. Nursing students must have a broad understanding of cancer content in order to provide safe, effective care in the clinical setting as they learn to recognize their own experiences in caring for cancer patients. Experienced nursing educators are aware that student nurses bring into any clinical learning situation their unique knowledge, values, fear, uncertainty and bias. The purpose of this study was to examine the experiences of nursing students caring for cancer patients. Method This descriptive qualitative study included participants who were Junior or Senior Baccalaureate nursing students and had provided care for at least one patient with cancer during clinical experiences. Focus group interviews were transcribed verbatim for analysis and coding using accepted qualitative techniques. Results Data analysis revealed student experiences to be varied in the type of cancer patient experiences. Four prevalent sub-themes emerged regarding student experiences: caring for patients and families, interactions between students and healthcare providers, student experiences with dying patients, and students’ prior experiences with cancer. Further discussion with students revealed a student perspective for strengthening cancer in the curriculum. Conclusion Preparing students to be comfortable with cancer patients across the cancer illness trajectory will provide students with the necessary skills to gain confidence in their cancer patient care.
Performance Measurements From Digital Optical Disk Systems

RCA has been working on digital data storage applications of optical discs since 1976. The basic optical technology utilizes ablative recording on laser sensitive materials, providing immediate playback of the stored data. Recently, complete systems have been built which fully establish the feasibility of digital optical disc storage for high data rate (beyond 200 Mb/s), high storage density (5x1010 bits/disc) and low bit error rate (<10-8). This paper briefly describes the hardware which has been developed. The main theme of the paper is the reporting and analysis of the test results that are being derived from this hardware.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Macroscopic Quantum Interference from Atomic Tunnel Arrays

Interference of atomic de Broglie waves tunneling from a vertical array of macroscopically populated traps has been observed. The traps were located in the antinodes of an optical standing wave and were loaded from a Bose-Einstein condensate. Tunneling was induced by acceleration due to gravity, and interference was observed as a train of falling pulses of atoms. In the limit of weak atomic interactions, the pulse frequency is determined by the gravitational potential energy difference between adjacent potential wells. The effect is closely related to the ac Josephson effect observed in superconducting electronic systems.
Fabrication of Silica-Coated Gold Nanorods Functionalized with DNA for Enhanced Surface Plasmon Resonance Imaging Biosensing Applications

A novel method for preparing gold nanorods that are first coated with a thin silica film and then functionalized with single-stranded DNA (ssDNA) is presented. Coating the nanorods with 3−5 nm of silica improves their solubility and stability. Amine-modified ssDNA is attached to the silica-coated gold nanorods via a reductive amination reaction with an aldehyde trimethoxysilane monolayer. The nanorods exhibit an intense absorption band at 780 nm, and are used to enhance the sensitivity of surface plasmon resonance imaging (SPRI) measurements on DNA microarrays.
Placebos in Clinical Practice and the Power of Suggestion

The use of deceptive placebos in the practice of clinical medicine is ethically justified within certain parameters. Thus, according to the Helsinki Declaration, placebos may be given to research s...
Determination of tin in silicate rocks by energy‐dispersive X‐ray fluorescence spectrometry

An accurate and precise method was developed for the determination of tin in geological materials using energydispersive x-ray fluorescence spectrometry. Previously analyzed silicate rocks were treated as unknowns in order to evaluate statistically the precision and accuracy of the method.