cssi/SciSciGPT-SciSciNet huggingface dataset:
Finding information in books: characteristics of full-text searches in a collection of 10 million books

Searching large collections of digitized books is a relatively new area in information-seeking and retrieval research, made possible by initiatives such as Google Books and the HathiTrust Digital Library. The availability of large full-text book collections is transforming how users search and interact with information in books, but the characteristics of these changes are unknown. This paper aims to provide insight into the characteristics of full-text searches in a large collection of digitized books and is the first step in a broader research agenda intended to improve book retrieval. To better understand the types of queries that users are issuing to full-text-book collections, we analyzed a full year of anonymized query logs from the HathiTrust Digital Library full-text search engine. We also manually classified a random sample of 600 queries to develop a taxonomy of book search query types. We found that users are beginning to search for information in books instead of searching for books. Searches still largely follow bibliographic models, but, as expected, new types of searches are beginning to take advantage of full-text capabilities. Additionally, comparing the results of our query log analysis to searches in other domains, we found similar search patterns including short queries, sessions with only a few queries, and users viewing only a few pages of results per query. We discuss how these findings can be used to characterize users of large full-text book collections.
Confidence Limits on MTBF for Sequential Test Plans of MIL-STD 781.

This paper presents tables for confidence limits on the MTBF of an exponentiadl istribution using observationsfr om sequential tests of MIL-STD 781. An example shows the use of the tables. The theory and calculation of the tables are explained in the Appendices.
Syntheses and studies of some metal chelates formed from 2-thiophenealdoxime

Abstract 2:1 complexes of 2-thiophenealdoxime with the dichlorides of zinc, cadmium, cobalt, nickel, copper and palladium have been prepared and studied. I.R. absorption frequencies are reported for the OH, CN conjugated, and NO stretching vibrations. Assignments of metal-chloride vibrations are made, and their relationship to the stereochemistry of the complexes is discussed.
A Consistent Set of Thermodynamic Values for Plutonium Mononitride

Values given in the literature for the heat of formation of plutonium mononitride range from — 70 to — 76 kcal/mole. This paper shows that if estimated entropy and high-temperature heat capacity data are used to derive a reasonable set of high-temperature thermal functions for the mononitride, ΔH0f,298 (PuN) values obtained by both second-and third-law methods from equilibrium data agree. The equilibrium data are from measurements reported in the literature and cover a range from 700° to about 3040°K. A calorimetric value of —70.2 kcal/mole reported for the PuN heat of formation appears to be in disagreement with the derived equilibrium value of — 76.0 kcal/mole, but this difference can be explained by a composition uncertainty.
Effect of Solvent Quality and Chain Confinement on the Kinetics of Polystyrene Bromination

We report on the kinetics of the bromination of free polystyrene (PS) chains in bulk solution and those anchored on flat solid substrates by performing the bromination reaction in different solvents, including nitrobenzene (NB), 1-chlorodecane (CD), 1-chloroundecane (CUD), and 1-chlorododecane (CDD), at various temperatures. We find that bulk bromination of PS follows the second-order kinetic in bromine and the reaction rate increases with increasing dielectric constant of the solvent (e). In spite of eCDD > eCD, the bulk bromination kinetics of PS in CDD is slower than that in CD because of lower solubility of PS in CDD than in CD. In addition, we demonstrate that the reaction rates for brominating PS brushes anchored to flat solid substrates are much slower than those for brominating free PS chains in bulk solution. We attribute this behavior to steric hindrance due to PS confinement on the substrate.
2009 Special Issue: Adaptive dynamic programming approach to experience-based systems identification and control

Humans have the ability to make use of experience while selecting their control actions for distinct and changing situations, and their process speeds up and have enhanced effectiveness as more experience is gained. In contrast, current technological implementations slow down as more knowledge is stored. A novel way of employing Approximate (or Adaptive) Dynamic Programming (ADP) is described that shifts the underlying Adaptive Critic type of Reinforcement Learning method ''up a level'', away from designing individual (optimal) controllers to that of developing on-line algorithms that efficiently and effectively select designs from a repository of existing controller solutions (perhaps previously developed via application of ADP methods). The resulting approach is called Higher-Level Learning Algorithm. The approach and its rationale are described and some examples of its application are given. The notions of context and context discernment are important to understanding the human abilities noted above. These are first defined, in a manner appropriate to controls and system-identification, and as a foundation relating to the application arena, a historical view of the various phases during development of the controls field is given, organized by how the notion 'context' was, or was not, involved in each phase.
Quenched carbon monoxide in fuel-lean flame gas

Abstract Laminar sheets of ethylene-air primary flames and of additional cooling air were interleaved to get a very lean gas of low mean temperature. At mean temperatures below a ceiling (of about 1250°K at atmospheric pressure) a few hundred to a few thousand ppm of CO were quenched at the boundaries of fuel-lean flame and persisted unreacted for many milliseconds in the mixed gas-the more CO being quenched the cooler and the thinner the flame sheets. Little CO was quenched at the hotter boundaries of fuel-rich flame sheets, whatever the mean temperature of the mixed gas. The observations are consistent with the approximation that all the flame-generated trace species except CO (H, O, H2, OH) remain equilibrated among themselves and decay together, but CO is not necessarily equilibrated with the others. Because its rate of reaction with OH can be slow compared to the decay of the other trace species, CO can remain largely unreacted as the others decay. Such quenching is expected only below a ceiling temperature (of about 1270°K at atmospheric pressure) and only if the cooling rate exceeds about − d T / d t > 340 T 2 c − 39.3 kcal / R T ° K / millisec ⁡ .
The regulation of yolk polypeptide synthesis in Drosophila ovaries and fat body by 20-hydroxyecdysone and a juvenile hormone analog

In adult female Drosophila melanogaster an increase in the synthesis and secretion of three yolk polypeptides (YPs) occurs during the first 24 hr after eclosion. During organ culture, these same polypeptides are synthesized and secreted into the medium by both fat body and ovaries. Two hormones, 20-hydroxyecdysone (20-HE) and a juvenile hormone analog (ZR-515) stimulate synthesis and secretion of YPs into the hemolymph of isolated female abdomens. The present experiments were undertaken to compare synthesis of YPs in normal females with YP synthesis in preparations deprived of anterior endocrine glands, and to find which hormone stimulates synthesis in the different organs. Separation of hemolymph proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that at eclosion incorporation of [35S]methionine into YP1 and YP2 was low and was barely detectable in YP3. Over the next 24 hr the rate of label incorporation increased for all the YPs. Isolation of female abdomens at eclosion prevented this increase in label incorporation but did not entirely abolish YP synthesis. Application of either ZR-515 or 20-HE to isolated abdomens stimulated up to ninefold label incorporation into three polypeptides which comigrated with YPs from normal vitellogenic females. The response of isolated abdomens to ZR-515 or 20-HE was first detectable between 90 and 135 min after hormone application. The stimulated bands were confirmed to be YPs by a comparison of peptide digests of each of the three labeled polypeptides with those of the yolk polypeptides from intact vitellogenic females. The hypothesis that the two hormones might act on different organs was tested by treating isolated female abdomens with various concentrations of either ZR-515 or 20-HE and then culturing the stimulated organ in vitro with [35S]methionine. The fat body responded to both hormones by synthesizing and secreting into the culture medium polypeptides which comigrated with the YPs found in hemolymph, whereas the ovary produced similar polypeptides only after ZR-515. These secreted polypeptides were confirmed to be YPs by repeating the experiment using organs from heterozygotes for both YP2 and YP3 electrophoretic variants. Such organs synthesized five polypeptides which comigrated with the corresponding yolk polypeptides. These findings are discussed in relation to a hypothesis for the action of the two hormones.
The irregular coloring number of a tree

Abstract An edge-coloring of a graph G is called vertex-distinguishing if for any two distinct vertices the multisets of colors assigned to incident edges differ. Let c ( G ) be the minimum number of colors necessary for such a coloring, and let n i denote the number of vertices of degree i in G . A simple count shows that c(G) ⩾ max {n 1 , C 1 n 2 1 2 } . We prove that if G is a tree then c(G) ⩽ max {n 1 , C 2 n 2 1 2 } .
Longitudinal Comparison of Multimedia Textbook Instruction with a Lecture in Radiology Education

Rationale and Objectives The purpose of this prospective randomized study was to compare the long-term instructional effectiveness of a computer-based radiology multimedia textbook (MMTB) with that of a traditional lecture. Methods Volunteer faculty/fellows and residents were randomly assigned to either a computer-based MMTB group or to a lecture group. The course content for each instructional group was the same. Pretests, posttests, and 1-year long-term retention tests were administered to both groups. The same 10 questions were on all tests. The resulting data were analyzed using analysis of variance procedures available on the Statistical Analysis System. Results A comparison of the long-term instructional effectiveness of an MMTB versus a lecture showed that the MMTB computer instructional method was at least comparable in spite of the initial short-term appearance of lecture superiority. Conclusion These results suggest a promising future for MMTB and other forms of computer-based education in radiologic instruction for medical students and radiologists.
PKCδ Clustering at the Leading Edge and Mediating Growth Factor-Enhanced, but not ECM-Initiated, Dermal Fibroblast Migration

We have previously shown that the immobilized extracellular matrices (ECMs) initiate cell migration and soluble growth factors (GFs) further enhance ECM-initiated cell migration. GFs alone cannot initiate cell migration. To further investigate the specificity of the two signaling mechanisms, we focused on the protein kinase C (PKC) family genes in primary human dermal fibroblasts (DFs). We here show that platelet-derived growth factor-BB (PDGF-BB) strongly stimulates membrane translocation and leading edge clustering of protein kinase C δ (PKC δ ). In contrast, attachment to collagen matrix alone does not cause the translocation. Although the kinase function of PKC δ is dispensable for initial membrane translocation, it is critical for its sustained presence at the cells's leading edge. Blockade of endogenous PKC δ signaling with dominant-negative kinase-defective PKC (PKC δ -KD) or PKC δ -small interfering RNA (siRNA) completely inhibited PDGF-BB-stimulated DF migration. In contrast, neither PKC δ -KD nor PKC δ -siRNA affected collagen-induced initiation of DF migration. Overexpression of a constitutively activated PKC δ (PKC δ -R144/145A) partially mimics the effect of PDGF-BB. However, PKC δ -KD, PKC δ -siRNA, or PKC δ -R144/145A does not affect PDGF-BB-stimulated activation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase1/2, or c-Jun N-terminal kinase. Instead, inhibition of PKC δ blocks PDGF-BB-stimulated activation of signal transducer and activator of transcription 3 (Stat3). This study unveiled the specificity of PKC δ in the control of DF migration.
Democracy and development in Zanzibar? Contradictions in land and environment planning

(1996). Democracy and development in Zanzibar? Contradictions in land and environment planning. Journal of Contemporary African Studies: Vol. 14, No. 2, pp. 221-245.
The effect of 5-thio-d-glucose on insect development and its absorption by insects

Abstract The effect of 5-thio- d -glucose on the development of larvae of Drosophila melanogaster Meig. and its absorption in the American cockroach, Periplaneta americana (L.), were investigated. A medium was produced which contained dried yeast and d -glucopyranose in amounts barely adequate to support the development of Drosophila larvae. d -Thioglucose incorporated into this medium at 0·03 times the molar concentration of d -glucose completely counteracted the nutritional benefits of d -glucose. American cockroaches were fed meals of d -thioglucose in aqueous solution. The distribution of the thiosugar was determined and compared with the distribution of d -glucose in cockroaches similarly fed with the latter sugar. The two sugars were absorbed and distributed among haemolymph, fat body, and the major portions of the gut in essentially the same way. Noteworthy differences were pointed out and discussed.
The evolving systemic and local biomarker milieu at different stages of disease progression in rat adjuvant-induced arthritis.

Rats with adjuvant-induced arthritis (AIA) were necropsied on 14 occasions during preclinical, acute clinical and chronic clinical stages of AIA progression to characterize local (joint protein extracts) and systemic (serum) levels of mediators regulating inflammation and bone erosion in conjunction with lymphoid tissue-specific leukocyte kinetics. Systemic increases in alpha1 acid glycoprotein, tumor necrosis factor-α (TNFα), interleukin (IL)-17, transforming growth factor beta (TGFβ), and chemokine (C–C motif) ligand 2 (CCL2) together with local IL-1α/β and TGFβ enrichment and local lymphoid hyperplasia preceded the onset of clinical disease and joint damage. Systemic upregulation of TNFα, IL-6, IL-17, TGFβ, IL-18, CCL2, receptor activator of nuclear factor-κβ ligand (RANKL), and prostaglandin E2 during acute and/or chronic AIA coincided with systemic leukocytosis and CD4+ T cell increase in blood and spleen. In contrast, progression of joint erosions during clinical AIA was associated with intra-articular increases in IL-1α/β, IL-6, RANKL, IL-17, TGFβ, CCL2, and KC/GRO and also a dramatic decline in osteoprotegerin. These data indicate that systemic and local events in inflammatory arthritis are discrete processes, driven by multiple cellular and humoral mediators with distinct kinetic profiles.
Too Much of a Good Thing? How Breadth of Extracurricular Participation Relates to School-Related Affect and Academic Outcomes During Adolescence

Although adolescents often participate in multiple extracurricular activities, little research has examined how the breadth of activities in which an adolescent is involved relates to school-related affect and academic performance. Relying on a large, multi-ethnic sample (N = 864; 55.9% female), the current study investigated linear and non-linear relationships of 11th grade activity participation in four activity domains (academic/leadership groups, arts activities, clubs, and sports) to adolescents’ sense of belonging at school, academic engagement, and grade point average, contemporarily and in 12th grade. Results of multiple regression models revealed curvilinear relationships for sense of belonging at school in 11th and 12th grade, grade point average in 11th grade, and academic engagement in 12th grade. Adolescents who were moderately involved (i.e., in two domains) reported a greater sense of belonging at school in 11th and 12th grade, a higher grade point average in 11th grade, and greater academic engagement in 12th grade, relative to those who were more or less involved. Furthermore, adolescents’ sense of belonging at school in 11th grade mediated the relationship of domain participation in 11th grade to academic engagement in 12th grade. This study suggests that involvement in a moderate number of activity domains promotes positive school-related affect and greater academic performance. School policy implications and recommendations are discussed.
Respiratory control in bullfrogs: Cutaneous versus pulmonary response to selective CO2 exposure

Bullfrogs,Rana catesbeiana, were exposed to high ambientP Co2 (15–22 Torr) at 20°C through either their skin or their lungs. The objective was to evaluate the effectiveness of the gas exchange surface not exposed to high CO2 to excrete the excess CO2 load. Frogs exposed to high CO2 through their skin increased pulmonary ventilation and controlled arterialP CO2, close to the normal value. In contrast, frogs that breathed CO2 did not increase their skin CO2 conductance, and arterialP CO2, increased significantly. These results support the concept that the lungs are the primary effector mechanism for respiratory control in the bullforg while the skin is a passive, poorly controlled avenue for CO2 loss. They also reveal that the lungs of this anuran are affective eliminators of CO2.
Negotiation Techniques for Health Care Professionals

Negotiation is an essential part of health care practice and is not formally taught during medical training. This article aims to improve the negotiation skills of readers by explaining the essential components of preparation before a negotiation and reviewing common techniques for optimizing negotiated agreements. The terms reservation point, target value, and best alternative to a negotiated agreement are defined, and their importance in negotiation preparation is explained. The concept of anchoring, or making the first offer, in a negotiation is reviewed, and important techniques for team negotiation are provided.
Interplanetary shock observations by Mariner 5 and Explorer 34

The solar wind flow behind shock fronts on June 25–26 and August 11, 1967 was studied using data from two spacecraft. For the last event the spacecraft were separated by 0.1 AU. In both cases there is a high degree of correlation between plasma parameters observed from the two spacecraft indicating that the features retain their identity over radial distances of at least 0.1 AU.
Evolution of a 193-nm bilayer resist for manufacturing

As 193 nm resist moves into production with minimum feature sizes approaching 100nm, bilayer resist is being evaluated more closely for certain applications. Our polymer design has been evolving to meet tighter outgassing requirements. Optical density, etch resistance and dissolution behavior are other considerations. The protecting group used in our 248 nm bilayer is not useful for 193 nm lithography because of the high optical density contribution from Si-Si linkage. Silicon was incorporated into a COMA platform for the first generation polymer. Maleic anhydride is used to modulate dissolution characteristics. The first generation 193 nm bilayer was optimized to print 120 nm L/S patterns with an attenuated PSM on a 0.6 NA Nikon S302. We will describe next generation platforms that address silicon outgassing concern. The lithographic performance of these resists was evaluated on a 0.6 NA Nikon S302 with a dark field mask. Results for 280nm pitch (1:1 L/S) and 245 nm pitch (105 nm L, 140 nm S) lithography are presented. Also shown is result for a 245 nm pitch (1:1 L/S) and 210 nm pitch (1:1 L/S) on a 0.75 NA ASML PAS 5500/1100. Outgassing data generated at MIT Lincoln Laboratory will be discussed.
Enhanced design of bowtie antennas over High-Impedance surfaces: An evolutionary approach

This work presents optimization of printed wideband antennas that are backed by High Impedance surfaces using a hybrid of constrained Evolutionary Programming (EP) and a MoM based simulator, This approach is used to arrive at optimized designs for semi-conformal bowtie antenna structures of about λ/10 thick with enhanced bandwidth performance, which are superior to previously reported structures. Two different designs are presented, where in each a bowtie antenna is used as radiating element and a mushroom-like EBG structure is used as its High Impedance ground-plane, with vias for one design, and without the vias for the other.
Metropolis light transport

We present a new Monte Carlo method for solving the light transport problem, inspired by the Metropolis sampling method in computational physics. To render an image, we generate a sequence of light transport paths by randomly mutating a single current path (e.g. adding a new vertex to the path). Each mutation is accepted or rejected with a carefully chosen probability, to ensure that paths are sampled according to the contribution they make to the ideal image. We then estimate this image by sampling many paths, and recording their locations on the image plane. Our algorithm is unbiased, handles general geometric and scattering models, uses little storage, and can be orders of magnitude more efficient than previous unbiased approaches. It performs especially well on problems that are usually considered difficult, e.g. those involving bright indirect light, small geometric holes, or glossy surfaces. Furthermore, it is competitive with previous unbiased algorithms even for relatively simple scenes. The key advantage of the Metropolis approach is that the path space is explored locally, by favoring mutations that make small changes to the current path. This has several consequences. First, the average cost per sample is small (typically only one or two rays). Second, once an important path is found, the nearby paths are explored as well, thus amortizing the expense of finding such paths over many samples. Third, the mutation set is easily extended. By constructing mutations that preserve certain properties of the path (e.g. which light source is used) while changing others, we can exploit various kinds of coherence in the scene. It is often possible to handle difficult lighting problems efficiently by designing a specialized mutation in this way. CR Categories: I.3.7 [Computer Graphics]: ThreeDimensional Graphics and Realism; I.3.3 [Computer Graphics]: Picture/Image Generation; G.1.9 [Numerical Analysis]: Integral Equations—Fredholm equations.
β-adrenoceptor signaling and its control of cell replication in MDA-MB-231 human breast cancer cells

MDA-MB-231 human breast cancer cells express high beta-adrenoceptor levels, predominantly the beta2 subtype. Receptor stimulation by isoproterenol evoked immediate reductions in DNA synthesis which were blocked completely by propranolol and were of the same magnitude as effects elicited by high concentrations of 8-Br-cAMP. Isoproterenol-induced inhibition of DNA synthesis was maintained throughout several days of exposure, resulting in a decrement in total cell number, and the effects were augmented by cotreatment with dexamethasone; an even greater effect was seen when cAMP breakdown was inhibited by theophylline, with or without addition of isoproterenol. Despite the persistent effect of isoproterenol, receptor downregulation was evident with as little as 1 h of treatment, and over 90% of the receptors were lost within 24 h. Receptor downregulation was paralleled by homologous desensitization of the adenylyl cyclase response to beta-adrenoceptor stimulation. Dexamethasone augmented the effects of isoproterenol on DNA synthesis but did not prevent receptor downregulation or desensitization. These results indicate that beta-adrenoceptors are effectively linked, through cAMP, to the termination of cell replication in MDA-MB-231 human breast cancer cells, and that activation of only a small number of receptors is sufficient for a maximal effect. Novel pharmacologic strategies that focus on cell surface receptors operating through adenylyl cyclase may offer opportunities to combat cancers that are unresponsive to hormonal agents, or that have developed multidrug resistance.
Interpretation of in situ observations in support of P-band radar retrievals

An in situ profile soil water content observation protocol developed at Oregon State University has been deployed in seven of the nine sites of the NASA AirMOSS project. (The other two sites run by USDA already had similar profile monitoring instrumentation installed.) The objective of the project is to develop a calibrated P-band radar which responds to the dielectric constant of the soil profile to produce the regional distribution of soil water content as a function of depth. The overall objective is to reduce the uncertainty in the carbon balance for North America by reducing the uncertainty in soil water content. This article demonstrates an annual time series of soil water content with depth as well as the wet and dry climate driven signals which produce a range of soil water content on which to calibrate the P-band radar. An example of the regional P-band radar retrieval calibrated using the in situ data is presented.
THE FINE STRUCTURE OF ISOLATED METAPHASE CHROMOSOMES.

Abstract Chromosomes have been isolated directly from cells in metaphase for study under the electron microscope by spreading on a Langmuir trough, followed by critical point drying. The morphology of metaphase chromosomes obtained by this method, when compared with the chromosome-like threads isolated from cells by the Waring blender method, indicates that the latter are artifacts resulting from the distortion of interphase nuclei by the blender. The presence in the blender isolate of various stages in the conversion of interphase nuclei to chromosome-like elongated masses supports this interpretation. Because the blender threads show a fibrous fine structure similar to the basic 250–280 A fibers making up interphase nuclei and metaphase chromosomes isolated by the Langmuir trough method, they are considered to be of nuclear origin, which would account for their staining characteristics.
Accessory cell function of human alveolar macrophages in B-cell activation induced by pokeweed mitogen.

Abstract The effect of alveolar macrophages (AM) on pokeweed mitogen (PWM)-stimulated immunoglobulin (Ig) secretion by unfractionated and monocyte-depleted human peripheral blood mononuclear cells was studied. Responsiveness in monocyte-depleted peripheral blood mononuclear cell populations could be partially restored by addition of autologous monocytes and to a lesser extent with AM. Addition of AM to unfractionated peripheral blood mononuclear cells resulted in significant inhibition of Ig secretion, especially at high (5–10 μg/ml) doses of PWM. The degree of suppression was proportional to the number of AM present. On the other hand, addition of monocytes to similar unfractionated peripheral blood mononuclear cell cultures did not result in suppression of Ig secretion at any of the doses of PWM used. Suppression by AM was not attributable to an alteration of response kinetics. The results demonstrate that mononuclear phagocytic cells are necessary for activation of polyclonal Ig secretion by human B cells and that AM are capable of suppressing this response.
738: Pregnancy complications and outcomes in women perinatally infected with human immunodeficiency virus

perinatally infected with human immunodeficiency virus Maria Miraz, Omar Duenas-Garcia, Daniella Fonseca, Priya Prasad, Maria Timoney, Rodney Wright Bronx Lebanon Hospital Center, Obstetrics and Gynecology, Bronx, NY, Montefiore Medical Center/Albert Einstein College of Medicine, Obstetrics & Gynecology and Women’s Health, Bronx, NY OBJECTIVE: To describe the pregnancy outcomes of women with perinatally acquired HIV (PAH) compared to those with non perinatally acquired HIV (NPAH), and to determine if factors such as ethnicity and income affect the pregnancy outcomes in these patients. STUDY DESIGN: We performed a retrospective case control study of HIV infected women who delivered in a large South Bronx NY hospital between January 2005 and December 2011. Cases were PAH patients and NPAH patients served as controls. The Student’s t-test was used for continuous variables and Chi square for categorical variables. Bivariate analyses were performed to determine the associations between birth outcome and pregnancy outcome with factors such as viral load, CD4 count and method of contracting HIV using both linear and logistic regression. RESULTS: 13 pregnancies were identified in the PAH group and 170 NPAH pregnancies. PAH patients were younger (mean age 21) compared to NPAH (mean age 31). 69% of PAH patients were Hispanic compared to 34% of NPAH (p 0.02). 23% of PAH and 27% of NPAH had some form of mental health problem (p ns). The median BMI for PAH patients was 26 where the mean BMI for NPAH was 31 (p 0.01). 37% of all patients reported some form of domestic or family violence (p ns). Preterm delivery and low birthweight were significantly higher in PAH (p 0.001). Median age at delivery for PAH was 35.4 weeks. Only 31% of PAH had an undetectable viral load at delivery compared to 78% of NPAH (p 0.001). PAH were 7.8x less likely to have an undetectable viral load at delivery but there were no mother to child HIV transmissions in the PAH group. There were two HIV infected infants born in the NPAH group to mothers with limited prenatal care (p 0.001). CONCLUSION: In a very high risk HIV infected patient population, numerous psychosocial factors may play a role in determining birth outcome. Careful attention to all of these factors may be key to eliminating mother to child transmission of HIV and improving birth outcomes.
Pancreaticoduodenectomy for suspected but unproven malignancy

background : Pancreaticoduodenectomy is an accepted surgical option for certain benign conditions and biopsy proven cancer. Whether this procedure should be performed when malignancy of the pancreas and periampullary region is suspected but not confirmed represents a fairly common intraoperative dilemma. patients and methods : Sixty-seven patients who had undergone pancreaticoduodenectomy during a 15-year period were evaluated retrospectively. results : The indications for resection were symptomatic benign conditions (n = 10, 15%), proven pancreatic or periampullary cancer (n = 37, 55%), and suspected but unproven malignancy (n = 20, 30%). The patients with suspected malignancy ranged in age from 27 to 73 years. Common findings in this group were abdominal pain (75%), jaundice (70%), weight loss (65%), and alcohol use (45%). There were 14 pancreatic and 6 ampullary masses. Biopsies obtained preoperatively (n = 15) and intraoperatively (n = 11) were nonconfirmatory. Postoperatively 9 patients (45%) were found to have tumors, including 6 pancreatic adenocarcinoma, 2 duodenal adenocarcinoma, and 1 islet cell tumor. Six of the 8 adenocarcinomas (75%) were stage I. Seven patients were alive 11 to 108 months later. The most common benign diagnosis was pancreatitis. There were 8 complications and 1 death. conclusions : Pancreaticoduodenectomy performed based on suspicion alone frequently reveals malignancy. Immediate and long-term outcomes are acceptable. These findings justify a continued aggressive approach to suspected pancreatic and periampullary malignancy.
Unusual aryl-porphyrin rotational barriers in peripherally crowded porphyrins.

Previous studies of 5,10,15,20-tetraarylporphyrins have shown that the barrier for meso aryl−porphyrin rotation (ΔG‡ROT) varies as a function of the core substituent M and is lower for a small metal (M = Ni) compared to a large metal (M = Zn) and for a dication (M = 4H2+) versus a free base porphyrin (M = 2H). This has been attributed to changes in the nonplanar distortion of the porphyrin ring and the deformability of the macrocycle caused by the core substituent. In the present work, X-ray crystallography, molecular mechanics (MM) calculations, and variable temperature (VT) 1H NMR spectroscopy are used to examine the relationship between the aryl−porphyrin rotational barrier and the core substituent M in some novel 2,3,5,7,8,10,12,13,15,17,18,20-dodecaarylporphyrins (DArPs), and specifically in some 5,10,15,20-tetraaryl-2,3,7,8,12,13,17,18-octaphenylporphyrins (TArOPPs), where steric crowding of the peripheral groups always results in a very nonplanar macrocycle. X-ray structures of DArPs indicate diffe...
Preparation and characterization of multiwalled carbon nanotube dispersions in polypropylene: Melt mixing versus solid‐state shear pulverization

Dispersions of multiwalled carbon nanotubes (MWNT) in polypropylene (PP) were prepared via conventional melt batch mixing and solid-state shear pulverization. The properties and structure of each system were assessed via linear viscoelasticity, electrical conductivity, PP crystallization kinetics, dynamic mechanical analysis, scanning electron microscopy, and small angle X-ray scattering. Increasing either the duration or the intensity of melt mixing leads to higher degrees of dispersion of MWNT in PP, although at the cost of substantial melt degradation of PP for long mixing times. Samples prepared by pulverization exhibit faster crystallization kinetics and higher mechanical stiffness than the melt blended samples, but in contrast show no measurable low frequency elastic plateau in melt rheology, and lower electrical conductivity than melt-mixed samples. X-ray scattering demonstrates that neither sample has uniform dispersion down to the single MWNT level. The results illustrate that subtle differences in the size and distribution of nanotube clusters lead to differences in the nanotube networks with strong impact on bulk properties. The results also highlight distinctions between conductive networks and load transfer networks and demonstrate that a complete and comparative picture of dispersion cannot be determined by simple indirect property measurements. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1426–1436, 2009
Novobiocin inhibits the SV40 enhancer activity.

Abstract Using a transient expression assay, we have analysed the effect of novobiocin, DNA topoisomeraseII inhibitor, on simian virus 40(SV40) enhancer activities. We used the recombinant clones containing typeI or II collagen promoters placed upstream of the bacterial chloramphenicol acetyltransferase (CAT) gene with or without SV40 enhancer. We observed the expected increase in CAT activities due to the presence of the SV40 enhancer. Interestingly, CAT gene expression of the enhancer-containing constructs were inhibited more sensitively by novobiocin than that of the enhancer-less construct. This findings lead us propose that DNA superhelicity mediated by topoisomeraseII is one of the important factor for the manifestation of SV40 enhancer activity.
Stage of Estrous Cycle, Time of Insemination, and Seasonal Effects on Estrus and Fertility of Holstein Heifers After Prostaglandin F2α

Abstract Stage of estrous cycle, time of insemination, and season of the year were examined for their influence on estrus and fertility of 223 Holstein heifers after prostaglandin F 2 α (treatment). Heifers treated during early stages (days 5 to 8) of the estrous cycle had shorter (by 11h) and less variable intervals to estrus compared with treatment of heifers during late stages (days 14 to 16) of the estrous cycle. A greater proportion of heifers in the early cycle treatment (79/81, 97%) were in synchronous estrus (20-h period) after treatment compared with the late cycle treatment (71/86, 83%). Conception rates were lower when early cycle heifers were inseminated at 80h after prostaglandin F 2 α than when inseminated according to estrous detection and also lower as compared with late cycle heifers inseminated at 80h. No differences in fertility were observed for late cycle heifers inseminated at 80h compared with those inseminated according to estrous detection. Season of the year had no influence on intervals to estrus or on proportion of heifers expressing estrus after prostaglandin F 2 α , regardless of stage of estrous cycle. Conception rate during winter, however, was higher in early but not late cycle heifers inseminated after prostaglandin F 2 α , as compared with fall or spring. Variability of interval to estrus and of fertility after inseminations by appointment at 80h appears to be due to stage of estrous cycle at time of prostaglandin F 2 α treatment rather than season of the year.
Encouraging Critical Thinking Through Expert Panel Discussions

Abstract. Encouraging critical thinking in classroom discussions when the class consists of students with similar backgrounds and professional experience can be challenging. This article reports on one method for introducing multiple viewpoints into discussions by requiring students to represent views from well-known personalities who are vocal in current controversies. This activity has improved student involvement, animated discussions and created high levels of interaction between students, and encouraged deeper levels of thinking and familiarity with important issues under public debate.
Mechanism of K562-induced human natural killer cell inactivation using highly enriched effector cells isolated via a new single-step sheep erythrocyte rosette assay.

Abstract In this study, we used preparations highly enriched in human natural killer (NK) cells to further characterize the mechanism of taget-cell-induced NK inactivation. Highly enriched populations of NK cells were obtained by a newly developed, single-step sheep red blood cell rosette assay. This method, which did not require any incubation steps to facilitate cell contact, permitted a rapid and efficient isolation if NK cells from adherent-cell-depleted peripheral blood lymphocytes. The non-rosetted cells had high NK activity, possessed large granular lymphocyte (LGL) morphology and expressed the NK-associated antigens Leu-11a, Leu-7, OKM1 and NKH-1. In contrast, the rosetted cells had significantly lower NK activity, possessed typical lymphocyte morphology and expressed the T-cell-associated marker OKT3. Next, we examined the ability of these NK-enriched effector cells (ECc) to become inactivated by K562. Functional studies revealed that ECc lost ≥95% of their lytic capacity following incubation with K562 at a ratio of 2/1 for 6 h. However, to achieve this level of inactivation, it was essential that the cell suspension be gently mixed every 90–120 min. Inactivation was not due to cell death and did not reflect changes in the percentages of cells bearing the Leu-11a, Leu-7, OKM1 and NKH-1 antigens, but was associated with an increase in cell surface concentration of OKM1. As judged by gross morphology, the percentages of LGL in ECc before and after treatment with K562 were essentially the same. Finally, K562-treated ECc also lost their ability to mediate antibody-dependent cellular cytotoxicity (ADCC), suggesting that both NK-cell-mediated cytotoxicity and ADCC may involve a common lytic pathway.
The photo-induced ignition of quiescent ethylene/air mixtures containing suspended carbon nanotubes

Abstract It has been previously shown by Ajayan et al. [Science 296 (2002) 705] that single-wall carbon nanotubes (SWCNTs) containing metal impurities ignite in air when exposed to a camera flash. Here it is demonstrated, for the first time to our knowledge, that the photo-induced ignition of SWCNTs can be used to photo-ignite gaseous fuel/air mixtures in a distributed quasi-homogeneous manner. Specifically, experiments have been carried out in which SWCNTs containing 70% iron impurity by weight are suspended in quiescent ethylene/air mixtures in a static combustion chamber and exposed to a Xe camera flash. Following the camera flash, the SWCNTs ignite, generating temperatures around 1500 °C, which induces the distributed quasi-homogeneous ignition of the ethylene/air mixtures; experiments were carried out for ethylene/air mixtures at equivalence ratios ranging from 0.5 to 1.5 and initial pressures of 1 and 2 bar and initial temperatures of 297 K. High-speed camera images and pressure measurements were obtained for both the SWCNT photo-ignition and, for purposes of comparison, the traditional automotive spark ignition of ethylene/air mixtures. Comparison of high-speed camera images obtained for these two ignition processes illustrates a quasi-homogeneous ignition with no discernible flame propagation for the SWCNT photo-ignition versus the point ignition followed by spherical flame propagation that occurs for spark ignition. Additionally, pressure measurements show that the SWCNT photo-ignition process results in accelerated energy release, particularly at lean to stoichiometric conditions, indicated by the rate of pressure increase, and higher peak pressures relative to spark ignition. Ignition delay and rise times, defined using measured pressure, are around 2–3× and 1.5–2× shorter for SWCNT photo-ignition compared to spark ignition at Φ = 0.7 and Φ = 1.0, respectively, but are nearly the same for SWCNT photo-ignition and spark ignition at Φ = 1.5.
Plasma cell myeloma marrow diagnosis including morphologic and phenotypic features.

Abstract This article emphasizes both the morphologic and phenotypic features of the bone marrow in plasma cell myeloma. It details the morphologic features of both trephine biopsies and marrow aspirations. It emphasizes the salient phenotypic features of marrow myeloma cells, in contrast with normal plasma cells. The myeloma cell phenotype is discussed from the perspective of both tissue section immunohistochemistry (IHC) and flow cytometry (FACS analysis). The specific criteria for myeloma diagnosis are discussed and illustrated in Figures 1–12. Finally, the emphasis is on the key morphologic and phenotypic diagnostic criteria of each of the plasma cell neoplasms.
Cellular metabolic rates in cultured primary dermal fibroblasts and myoblast cells from fast-growing and control Coturnix quail

Fibroblast cells have been extensively used in research, including in medicine, physiology, physiological-ecology, and conservation biology. However, whether the physiology of fibroblasts reflects the physiology of other cell types in the same animal is unknown. Dermal fibroblasts are responsible for generating connective tissue and involved in wound healing, but generally, this cell type is thought to be metabolically inactive until it is required at the site of tissue damage. Thus, one might question whether fibroblasts are a representative model system to portray the metabolic profile of the whole organism, as compared with cells isolated from other tissues, like muscle, brain or kidneys. To explore whether fibroblasts have the same metabolic profile as do myoblast cells, we cultured cells from day-old chicks of quail (Coturnix coturnix japonica) selected for fast-growth or normal growth (our control group). Our results suggest that isolated primary fibroblasts and myoblast cells had higher rates of glycolysis, oxygen consumption and more mitochondria in the fast-growing line than in the control line. Our findings lend support for the idea that fibroblasts are a representative cell system to characterize the whole organism metabolic signature at the cellular-level. These data are striking, however, because fibroblasts had higher rates of metabolism for every parameter measured than myoblast cells isolated from the same individuals.
Compact Encodings of List Structure

List structures provide a general mechanism for representing easily changed structured data, but can introduce inefficiencies in the use of space when fields of uniform size are used to contain pointers to data and to link the structure. Empirically determined regularity can be exploited to provide more space-efficient encodings without losing the flexibility inherent in list structures. The basic scheme is to provide compact pointer fields big enough to accommodate most values that occur in them and to provide “escape” mechanisms for exceptional cases. Several examples of encoding designs are presented and evaluated, including two designs currently used in Lisp machines. Alternative escape mechanisms are described, and various questions of cost and implementation are discussed. In order to extrapolate our results to larger systems than those measured, we propose a model for the generation of list pointers and we test the model against data from two programs. We show that according to our model, list structures with compact cdr fields will, as address space grows, continue to be compacted well with a fixed-width small field. Our conclusion is that with a microcodable processor, about a factor of two gain in space efficiency for list structure can be had for little or no cost in processing time.
Ginzburg-Landau equations, interphase surface energy, and the intermediate state of superconductors with a paramagnetic normal state

The effects of a paramagnetic normal state on the superconducting Ginzburg-Landau (GL) equations, the interphase surface energy ${\ensuremath{\sigma}}_{\mathrm{ns}}$ and the intermediate-state critical field ${B}_{\mathrm{cI}}$ of thin films in a perpendicular field are calculated. For a linear $H(B)$ relation, the scaling of ${\ensuremath{\lambda}}_{L}$ into $\frac{{\ensuremath{\lambda}}_{L}}{{(1+4\ensuremath{\pi}\ensuremath{\chi})}^{\frac{1}{2}}}$ introduced by Tachiki et al. is adequate for the GL equations and ${\ensuremath{\sigma}}_{\mathrm{ns}}$ but not for ${B}_{\mathrm{cI}}$. For a nonlinear $H(B)$ relation, as might occur for spontaneous ferromagnetism or for fields large enough that the magnetization saturates, neither the GL equations nor ${\ensuremath{\sigma}}_{\mathrm{ns}}$, nor ${B}_{\mathrm{cI}}$, can be obtained by scaling the nonmagnetic case. These results should be applicable to magnetic superconductors such as Er${\mathrm{Rh}}_{4}$${\mathrm{B}}_{4}$.
Everyday and medical life choices: decision-making among 8- to 15-year-old school students.

Summary How much do young patients expect to be involved in medical decisions affecting them? We are investigating this question during interviews with 8- to 15-year-olds having orthopaedic surgery. Many youngsters taking part in our research project on consent to surgery are more than usually dependent on their parents. We wondered how their views would compare with those of their peers at school. This paper reports a schools survey carried out as a background to the research with young people in hospital. Students in seven schools answered questionnaires on choices about late-night television viewing, new friends, timing homework, seeing their family doctor and consenting to surgery. They were asked about agreement with their parents, how they negotiate disagreement, and when they think they were/will be old enough to make everyday and medical decisions without their parents' help.