cssi/SciSciGPT-SciSciNet huggingface dataset:
Development of a New Plunger-lift Model using Smart Plunger * ) Data

The problem of liquid loading, which is common to all mature gas producing wells, needs to be identified and solved in order to achieve efficient gas production. Field operators not only need to select the best possible technical solution for liquid loading, but also one that is cost effective. A popular remedial solution for liquid loading in onshore gas wells is plunger lift. However, this technology is currently designed using simplistic models with restrictive assumptions, coupled with field experience. This paper provides an overview of the various plunger lift models available in the public domain and highlights their fundamental limitations. A new approach to plunger lift modeling is then proposed, which assumes the availability of pressure and temperature data provided by smart plungers. These devices are equipped with internal gauges to record pressure and temperature with time, which can be downloaded whenever the plunger is at surface. In the proposed model, these data are coupled with the fundamental conservation equations of mass, momentum and energy that govern the dynamics of plunger lift. The main difficulties of dealing with transient flows that are typical of plunger lift operations are identified. These include the dynamic interactions between reservoir, annulus and tubing, which are particularly relevant in tight gas reservoirs. The overall objective is to develop a model capable of predicting plunger lift operations in a more realistic fashion and so optimize lift cycles.
New approaches for detecting thresholds of human nephrotoxicity using cadmium as an example.

Damage to the kidneys is one of the primary toxic actions of metals. Nephrotoxic substances not only cause renal disease directly, but they can also destroy renal reserve capacity, potentially plac...
The effect of peer contact upon physiological response to maternal separation.

The response of both human and nonhuman primate infants to separation from their mothers is characterized by agitation or protest behaviors followed by a behavioral depressive reaction. In monkeys, this behavioral syndrome has striking physiological correlates, including heart rate and sleep disturbances. There is, however, considerable individual variability in response to maternal separation. The authors hypothesized that the amount of contact with particular, familiar conspecifics might account for some of this variability. In support of this notion, data are presented that indicate that pigtailed monkey infants who have been separated from their mothers but who maintain relatively high levels of peer contact do not show as severe decreases in heart rate during maternal separation as do those that exhibit less peer contact.
Distraction-fixation in the primary treatment of metacarpal bone loss

Nine patients seen in civilian practice with severe open injuries of the hand, including loss of portions of some or all of the metacarpals, were treated by primary restoration of metacarpal length and alignment by distraction fixation with the use of transverse intermetacarpal Kirschner wires. An external fixation device was added in two of the nine patients. Severe associated soft tissue injuries were present in all but one patient. Two injuries were caused by firearms, and the other seven by heavy machinery. Contractures of the joints were prevented by the use of a second set of wires to position the metacarpophalangeal joints in 70° of flexion and the first metacarpal in abduction and pronation. Staged closure of wounds by local or distant flaps and secondary reconstructions by bone, nerve, and tendon grafts or transfers were necessary in all and required an average of almost 2 years until treatment was completed. All except the one child and the one most recently injured patient have returned to employment or vocational retraining. Follow-up was 24 to 78 months from injury.
Analysis of the Water Permeability of Human Granulocytes at Subzero Temperatures in the Presence of Extracellular Ice

The plasma membrane water permeability of human granulocytes in the presence of extracellular ice was determined experimentally on a cryomicroscope. Transient volumes of individual cells were measured at constant subzero temperatures subsequent to ice nucleation. Permeability values were deduced by adjustment of multiple parameters in a model to obtain an optimal fit to the data. The permeability was determined to be a function of both temperature and intracellular solute osmolality, with a reference value at 0 degrees C of 0.407 micrometers/atm.min and temperature and solute coefficients of 218kJ/mol and 1.09 Osm/kg.
One-step isolation of α1-Acid glycoprotein

alpha 1-Acid glycoprotein could be isolated by a one-step extraction method from human sera and plasma. Protein recovered in the water phase after extraction with phenol at 70 degrees C for 20 min was verified as human alpha 1-acid glycoprotein when it was compared with the reference standard human alpha 1-acid glycoprotein by Ouchterlony double immunodiffusion, sodium dodecylsulfate-polyacrylamide gel electrophoresis, Western blot analysis, and periodic acid-Schiff stain. The present isolation procedure is simple and fast, and can extract about 81% of the total alpha 1-acid glycoprotein in the sera and plasma, as determined by radial immunodiffusion.
Matrix metalloproteinase-induced genomic instability.

Increased expression of matrix metalloproteinases (MMPs) is associated with nearly every tumor type. Although many studies have shown that MMPs can promote malignancy, recent evidence has revealed that MMPs can play a causative role also in the earliest stages of cancer development. A complex story is now emerging in which MMPs not only compromise cell–cell and cell–substratum adhesion processes that impact genomic surveillance mechanisms but also act directly on molecules at the cell surface to stimulate physiological processes that cause genetic alterations. Delineating the mechanisms involved in these processes and identifying how they are coordinated in vivo could aid identification of the crucial contribution of MMPs to tumorigenesis.
Tissue-specific determinants of anisotropic conduction velocity in canine atrial and ventricular myocardium.

Electrical conduction is very rapid and highly anisotropic in atrial fiber bundles, such as the crista terminalis. In contrast to left ventricular myocardium in which the ratio of longitudinal to transverse conduction velocities is approximately 3, propagation velocity in the crista terminalis is approximately 10 times greater in the longitudinal than in the transverse direction. To elucidate potential determinants of these distinct conduction properties, we characterized structural and molecular features of intercellular coupling in the crista terminalis and left ventricular myocardium of the canine heart. Analysis of the number and spatial orientation of myocyte interconnections at gap junctions revealed that a typical left ventricular myocyte was connected to 11.3 +/- 2.2 other myocytes. Approximately equal numbers of connections occurred between ventricular myocytes juxtaposed in side-to-side and end-to-end orientation. In contrast, a typical myocyte of the crista terminalis was connected to only 6.4 +/- 1.7 other cells (P < .05), but nearly 80% of these connections occurred between cells oriented in an end-to-end configuration. In comparison with the ventricular pattern, this spatial distribution of connections would limit intercellular current transfer between laterally apposed cells and thereby enhance anisotropy of conduction velocity in the longitudinal and transverse directions. Ultrastructural analysis showed that crista terminalis myocytes were connected by numerous small gap junctions that occurred in relatively simple, straight intercalated disks. Northern blot analysis showed approximately equivalent amounts of mRNAs encoding the gap junction channel proteins connexin43 and connexin45 but approximately four times more connexin40 mRNA in crista terminalis than in the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)
Cardiovascular risk factors in affective disorder

100 patients with affective disorder (unipolar affective disorder and bipolar affective disorder) were evaluated for evidence of increased risk for the major cardiovascular risk factors including hypertension, hypercholesterolemia, obesity, and cigarette use. Unipolar affective disorder patients showed no evidence of increased cardiovascular risk compared to population controls. Bipolar affective disorder patients displayed increased systolic blood pressure, definite hypertension, and use of cigarettes. These findings are consistent with a link between affective disorders and excess cardiovascular mortality.
Does higher peer socio-economic status predict children's language and executive function skills gains in prekindergarten?

Abstract Because most public preschool programs are means tested, children enrolled in these programs accordingly have peers from predominantly low-income families who present lower cognitive skills and more behavioral problems, on average. The present study examined the role of having a higher percentage of peers from higher-SES families on gains in children's receptive vocabulary and executive function skills at the end of prekindergarten. Participants included 417 children attending a prekindergarten program that is not means tested. Findings indicated that having a higher percentage of peers from higher-SES families showed small, positive associations with greater gains in end-of-prekindergarten receptive vocabulary and executive function skills. Results are discussed in the context of current proposals to increase access to publicly funded preschool for higher-income families.
Manipulation and Mobilization of the Cervical Spine

Objectives: To review the scientific evidence for both manipulation and mobilization therapies for the cervical spine. This report presents the results from a review of the medical, chiropractic, osteopathic, physical therapy, and dental literature on the efficacy, complications, and indications for manipulation and mobilization of the cervical spine, and the appropriateness ratings of indications for manipulation and mobilization. Methods: Articles were identified through searches of computerized databases [MEDLINE [Index Medicus], CHIROLARS [Chiropractic Literature Analysis and Retrieval System] etc.], review of article's bibliographies, and advice from experts. This yielded 362 primary articles on cervical spine manual therapy and 145 articles on complications. Priority was given to research that used randomized, controlled trial [RCT] designs. Second priority was given to non-experimental studies including cohort, case-control, and cross sectional studies. Case series and case reports were given lowes...
Effect of HIV genotypic drug resistance testing on the management and clinical course of HIV-infected children and adolescents

SummaryThe clinical utility of genotypic drug resistance testing (DRT) in HIV-infected children on antiretroviral therapy (ART) is not well understood. HIV-infected patients aged <19 years undergoing DRT for virological failure were retrospectively enrolled. Indications for DRT and changes in HIV RNA load were recorded. Between January 2000 and December 2006, 57 patients had DRT. The most common indication for DRT was poor ART adherence (57.7% of patients). ART was changed in 50.9% of patients after DRT. Poor adherence was cited by clinicians for not changing ART significantly more often than any other reason (47.3%, P < 0.001). After DRT, significant improvement in HIV RNA load occurred independent of ART changes, though patients whose ART was modified were more likely to become undetectable (31.5% versus 7.0%, P < 0.001). Poor adherence was a significant factor for ordering DRT and for not changing ART in HIV-infected children.
Inophore-releasable lumenal Ca2+ stores are not required for nuclear envelope assembly or nuclear protein import in Xenopus egg extracts

Abstract The nuclear envelope of higher eukaryotes disassembles early in mitosis and reassembles later around the daughter chromosomes. Previous in vitro work supported the hypothesis that the release of lumenal Ca2+ stores via inositol 1,4,5-trisposphate-gated Ca2+ channels is required for nuclear assembly in Xenopus egg extracts [1,2]. Other work suggested that lumenal Ca2+ stores are required for nuclear protein import using vitro [3]. Here, we rigorously tested the role of lumenal Ca2+ stores in nuclear assembly and nuclear protein import using Xenopus egg extracts. Lumenal Ca2+ stores were depleted by pretreating the extracts with Ca2+ ionophores (ionomycin, A23187) or inhibitors of Ca2+-sequestering pumps (thapsigargin, cyclopiazonic acid). Extracts depleted of lumenal Ca2+ stores assembled nuclei around demembranated sperm chromatin. These nuclei were morphologically indistinguishable from control nuclei when viewed by light or electron microscopy. Nuclei lacking lumenal Ca2+ stores excluded membrane-impermeant fluorescent dextrans, indicating the formation of a sealed nuclear envelope, and they accumulated a fluorescent nucleophilic protein, nucleoplasmin, indicating that nuclear pore complexes were functional. DNA replication occurred in the lumenal-Ca2+-depleted nuclei, though less efficiently than control nuclei. Our demonstration that in vitro nuclear import does not depend on lumenal Ca2+ stores confirs a previous unpublished observation by Greber and Gerace [3], and suggests that import defects seen in ionophore-treated living cells are not directly due to the loss of lumenal Ca2+. Finally, we concluded that, contrary to our expectations, lumenal Ca2+ stores are not required for nuclear envelope assembly in Xenopus egg extracts.
The Interrelationships between Victimization, Fear, and Acculturation among Asian Immigrants

AbstractThe current research addresses fear of crime, acculturation, criminal justice understanding, and victimization measures in a sample of Asian immigrants in Harris County, Texas. Data stems from research conducted by Kercher and Kuo (2008). This study includes 729 surveys completed by adult Chinese, Korean, Vietnamese, and Taiwanese immigrants at community centers and churches in 2007. Findings suggest significant differences in fear of crime (and to a lesser extent in variations of acculturation) and understanding of the criminal justice system when controlling for victimization status. Support was absent in bivariate and multivariate analysis for ethnic differences in victimization. Additional findings indicate that reporting victimization only significantly varies based on time spent in the United States. Discussion of findings, future directions, and policy recommendations (including community mobilization and educational efforts) are provided.
Mitochondrial DNA mutations in human degenerative diseases and aging

A wide variety of mitochondrial DNA (mtDNA) mutations have recently been identified in degenerative diseases of the brain, heart, skeletal muscle, kidney and endocrine system. Generally, individuals inheriting these mitochondrial diseases are relatively normal in early life, develop symptoms during childhood, mid-life, or old age depending on the severity of the maternally-inherited mtDNA mutation; and then undergo a progressive decline. These novel features of mtDNA disease are proposed to be the product of the high dependence of the target organs on mitochondrial bioenergetics, and the cumulative oxidative phosphorylation (OXPHOS) defect caused by the inherited mtDNA mutation together with the age-related accumulation mtDNA mutations in post-mitotic tissues.
Luteinization and Steroidogenic Activity of Rat Ovarian Follicles Cultured in Vitro

Ovarian follicles were isolated from estrous rats and cultured in vitro for 1–6 days. After one day of culture there were no changes in the morphology of the follicles. In about 40% of the follicles cultured for 2 days, oocytes showed signs of degeneration. This was followed by the appearance of luteinized nests of cells in the theca and/or granulosa layers. On the 3rd day of culture all follicles had degenerated oocytes, and luteinization became more intense. Progestin was synthesized at a steady rate throughout the 3–day culture period. In contrast, estrogen was synthesized only from days 0–2 of incubation and showed a consistent decline on day 3 in all cultures. Very significant increases in progestin syntheses were obtained by the addition of 10 ng of LH to the culture medium. One hundred ng produced a significant but erratic increase in progestin syntheses. The addition of 10 ng of LH produced a minimal increase in estrogen synthesis while the 100 ng caused a very significant rise during days one and...
Mutagenicity of some fluoro-derivatives of benzo[a]pyrene

Abstract Benzo[ a ]pyrene (BP) and its 4 fluoroderivatives substituted at positions 7(BP-7F), 8(BP-8F), 9(BP-9F) and 10 (BP-10F) were mutagenic in strains TA98 and TA1538 of Salmonella typhimurium , when tested in the presence of liver S-9 or microsomes from Aroclor or 3MC-treated rats. While the presence of fluorine at position 10 resulted in some reduction in mutagenicity, several-fold increase in mutagenicity occurred when fluorine was substituted at position 8. Our data suggests additional involvement of other metabolites in the mutagenicity of BP.
Recombinant Factor VIIa in Trauma Patients Without Coagulation Disorders

Recombinant activated factor VIIa (rFVIIa) has many clinical applications for patients with congenital bleeding disorders and in a variety of clinical settings. Additional studies in the future are ongoing and should provide the clinical anesthesiologist an additional option during certain bleeding states. Specific recommendations as to timing of administration and frequent monitoring of ionized calcium status are suggested at this time. Optimization of fibrinogen levels, platelet levels, pH, and body temperature will enhance efficacy of rFVIIa.
A synergistic combination of algal wastewater treatment and hydrothermal biofuel production maximized by nutrient and carbon recycling

This study introduces and analyzes a novel system for algal biofuel production that synergistically integrates algal wastewater treatment with hydrothermal liquefaction (HTL) of wastewater biosolids and algae into bio-crude oil. This system maximizes the biofuel potential of wastewater inputs by internally capturing and recycling carbon and nutrients – a powerful concept referred to as multi-cycle nutrient reuse, which amplifies waste nutrients into multiple cycles of algal biomass and bioenergy production. We call this system “Environment-Enhancing Energy” (E2-Energy) because it can simultaneously improve conventional wastewater treatment by nutrient removal and production of a large amount of biofuel co-products. Moreover, E2-Energy resolves several key bottlenecks commonly associated with large-scale algal biofuel production including: contamination of target high-oil algal cultures, high nutrient costs/usage, unsustainable fresh water usage, and large energy inputs for dewatering/extraction. A series of algal cultivation and HTL experiments were conducted to confirm the primary steps and performance characteristics of the E2-Energy system. These experiments showed: (1) low-oil, mixed algal–bacterial biomass can be successfully cultured with the recycled HTL aqueous product; (2) both organics and nutrients are removed from wastewater during algal–bacterial biomass production (63–95% reduction); (3) this low-oil, algal–bacterial biomass can be converted into bio-crude oil via HTL with a high yield (∼50%) and a net positive energy balance; and (4) the HTL step re-releases nutrients to an aqueous phase product that can be recycled back to step (1). This repeating loop of steps 1–4 facilitates multi-cycle reuse of nutrients and thus provides biomass amplification. A mathematical model was also developed using STELLA® to simulate mass balances for long-term E2-Energy operations with internal recycling of nutrients and carbon. The model results showed that E2-Energy can amplify the biomass and biofuel production from wastewater by up to 10 times, which gives it the potential to replace all US petroleum imports using only current wastewater feedstocks and carbon dioxide from the atmosphere or point sources. Thus, E2-Energy represents a major paradigm shift—where wastewater treatment systems become optimized biofuel producers with enhanced effluent quality, which provides a viable and advantageous pathway to sustainable, carbon-neutral energy independence.
A rapid and simple method for the determination of iodine values using derivative Fourier transform infrared measurements

Abstract A rapid method for determining the iodine value, IV, of vegetable oils was developed. The method is based on using derivative Fourier transform infrared measurements. The infrared derivative spectrum of pure vegetable oils was measured between 4000–400 cm−1 and the heights of the derivative spectrum for functional group band maxima were determined. Pure vegetable oils as samples were used throughout this study. The method was used for determination of iodine value of 12 edible vegetable oils as well as castor and linseed oils. Oils with IV ranging from 10 to 190 were tested and found to give satisfactory values. Results were obtained with good precision and accuracy, typically exhibiting 5% relative standard deviation.
Apolipoprotein A-IV: a protein intimately involved in metabolism

The purpose of this review is to summarize our current understanding of the physiological roles of apoA-IV in metabolism, and to underscore the potential for apoA-IV to be a focus for new therapies aimed at the treatment of diabetes and obesity-related disorders. ApoA-IV is primarily synthesized by the small intestine, attached to chylomicrons by enterocytes, and secreted into intestinal lymph during fat absorption. In circulation, apoA-IV is associated with HDL and chylomicron remnants, but a large portion is lipoprotein free. Due to its anti-oxidative and anti-inflammatory properties, and because it can mediate reverse-cholesterol transport, proposed functions of circulating apoA-IV have been related to protection from cardiovascular disease. This review, however, focuses primarily on several properties of apoA-IV that impact other metabolic functions related to food intake, obesity, and diabetes. In addition to participating in triglyceride absorption, apoA-IV can act as an acute satiation factor through both peripheral and central routes of action. It also modulates glucose homeostasis through incretin-like effects on insulin secretion, and by moderating hepatic glucose production. While apoA-IV receptors remain to be conclusively identified, the latter modes of action suggest that this protein holds therapeutic promise for treating metabolic disease.
In-situ monitoring during MBE growth of InAs based heterostructures

The use of reflectance anisotropy spectroscopy (RAS) for the real time monitoring of the growth of InAs based heterostructures by molecular beam epitaxy within the photon energy range 1.5–5.0 eV is reported. The complete desorption of the native oxide for InAs substrates was monitored using a single wavelength and epitaxial growth of InAs was also monitored under both the As- and In-rich surface reconstructions. Further the changes in the RAS and reflectance data for ternary and quaternary layers demonstrated the usefulness of this system as an in-situ tool for monitoring the composition of layers for this important class of narrow gap semiconductors. In addition, emissivity corrected pryometry temperature was measured using the RAS system. Growth rates for the individual layers in a heterostructure were also determined from an analysis of the reflectance data.
Measurement of f -Values in the Iron Spectrum with Applications to Solar and Stellar Atmospheres

The relative $f$-values of 47 spectral lines of Fe I have been derived from measurements of intensities in emission of lines excited in an electric furnace. The measurements were made photoelectrically. The $f$-values were measured relative to King's previously determined values and are on the same scale. Lines with excitation potential of low term up to 3.5 volts are included.The $f$-values derived have been used to plot a solar curve of growth. The scatter of the points for high energy level lines is large. This is due mainly to the fact that lines whose low term is of odd parity are apparently consistently too strong in the sun and those of even parity too weak. On the other hand curves of growth for the giant stars $\ensuremath{\gamma}$-Cygni and $\ensuremath{\alpha}$-Persei exhibit a much smaller scatter of points and no evidence of odd-even difference. Measurements of laboratory pressure shifts show systematic odd-even differences. These tests indicate that the effect observed in the sun is real and suggests that it may be due to the relatively high pressure in the solar atmosphere. If this is true the practice of using relative $f$-values derived from the solar curve of growth in the study of stellar atmospheres should be reconsidered.
Glass transition temperatures of several fluorine‐containing polymers

The glass transition temperatures Tg of several fluorine-containing polymers were determined by use of the differential scanning calorimeter. Values between −3 and 230°C were obtained. In polymers of α-olefins, Tg increases with the fluorine content of the backbone and the length of the n-perfluoroalkyl branch. In styrene polymers Tg also is higher if the backbone contains fluorine but nearly the same Tg's are found for polymers with phenyl and pentafluorophenyl groups. Saturated polymers of perfluoro-α,ω-dienes have lower Tg's than polyperfluoro-α-olefins. The Tg's of chloroperfluoropolymers are higher than those of perfluoropolymers. Polyperfluoropentadiene-1,3 has the lowest Tg of the polymers examined. Polyperfluoropentadiene-1,3 forms by 1,4-addition.
The geochemistry of fallout plutonium in the North Atlantic: I. A pore water study in shelf, slope and deep-sea sediments

Abstract The distribution of fallout plutonium between pore waters and sediments in the Northwest Atlantic is examined in order better to define the potential for Pu migration from and within marine sediments. Along a transect of seven cores collected between Woods Hole and Bermuda, the solid phase 239,240Pu, 210Pbex and 137Cs results do not suggest that any of these tracers are preferentially mobile within the cores. Pore water Pu activities appear to be controlled primarily by the distribution of Pu in the solid phase, with an operationally determined distribution coefficient, Kd, in the range of 0.2−23 × 104. There is a trend in the Kds along the transect, with higher values in the 104–105 range on the shelf and slope, to lower values 239,240 Pu cm 2 year). Sediment mixing models are not significantly altered by the inclusion of Pu diffusion terms, since the pore water terms are so small relative to typical sediment mixing rates.
Bilateral Horner's Syndrome in Cluster Type Headaches

A patient with cluster type headaches demonstrated bilateral and alternating ocular sympathetic dysfunction during a spontaneous as well as a nitroglycerin-induced attack. Biochemical evaluation revealed postganglionic pupillary dysfunction on the symptomatic side and preganglionic pupillary dysfunction contralaterally. These findings defy a simple explanation regarding a central or peripheral origin of the oculocephalic sympathetic dysfunction.
Commissioning and Performance of the ATLAS Transition Radiation Tracker with First High Energy pp and Pb-Pb collisions at LHC

Abstract The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing ∼30 measurements with position resolution of about 120 μm for charged particle tracks with |η| pT > 0.5 GeV. Along with continuous tracking, it provides particle identiﬁcation capability through the detection of transition radiation, X-ray photons generated by high momentum particles in the many polymer ﬁbers or ﬁlms that ﬁll the spaces between the straws. Custom-built analog and digital electronic read-out are optimized to operate at the LHC design luminosity. In this article, a review of the commissioning and ﬁrst operational experience of the TRT detector will be presented. Emphasis will be given to performance studies based on the reconstruction and analysis of proton-proton collision data collected at the LHC. In addition, the response of the TRT detector to the extremely high track density conditions encountered during the ﬁrst heavy ion LHC collisons will be presented.
Expression of signaling components in embryonic eyelid epithelium.

Closure of an epithelium opening is a critical morphogenetic event for development. An excellent example for this process is the transient closure of embryonic eyelid. Eyelid closure requires shape change and migration of epithelial cells at the tip of the developing eyelids, and is dictated by numerous signaling pathways. Here we evaluated gene expression in epithelial cells isolated from the tip (leading edge, LE) and inner surface epithelium (IE) of the eyelid from E15.5 mouse fetuses by laser capture microdissection (LCM). We showed that the LE and IE cells are different at E15.5, such that IE had higher expression of muscle specific genes, while LE acquired epithelium identities. Despite their distinct destinies, these cells were overall similar in expression of signaling components for the “eyelid closure pathways”. However, while the LE cells had more abundant expression of Fgfr2, Erbb2, Shh, Ptch1 and 2, Smo and Gli2, and Jag1 and Notch1, the IE cells had more abundant expression of Bmp5 and Bmpr1a. In addition, the LE cells had more abundant expression of adenomatosis polyposis coli down-regulated 1 (Apcdd1), but the IE cells had high expression of Dkk2. Our results suggest that the functionally distinct LE and IE cells have also differential expression of signaling molecules that may contribute to the cell-specific responses to morphogenetic signals. The expression pattern suggests that the EGF, Shh and NOTCH pathways are preferentially active in LE cells, the BMP pathways are effective in IE cells, and the Wnt pathway may be repressed in LE and IE cells via different mechanisms.
Inferring Physical Conditions in Interstellar Clouds of H2

We have developed a code that models the formation, destruction, radiative transfer, and vibrational/ rotational excitation of H2 in a detailed fashion. We discuss generally how such codes, together with Far Ultraviolet Spectrographic Explorer (FUSE) observations of H2 in diffuse and translucent lines of sight, may be used to infer various physical parameters. We illustrate the effects of changes in the major physical parameters (UV radiation field, gas density, metallicity), and we point out the extent to which changes in one parameter may be mirrored by changes in another. We provide an analytic formula for the molecular fraction, fH2, as a function of cloud column density, radiation fields, and grain formation rate of H2. Some diffuse and translucent lines of sight may be concatenations of multiple distinct clouds viewed together. Such situations can give rise to observables that agree with the data, complicating the problem of uniquely identifying one set of physical parameters with a line of sight. Finally, we illustrate the application of our code to an ensemble of data, such as our FUSE survey of H2 in the Large and Small Magellanic Clouds, in order to constrain the elevated UV radiation field intensity and reduced grain formation rate of H2 in those low-metallicity environments. Subject headings: ISM: clouds — ISM: molecules — molecular processes
A computer vision system for the inspection of light emitting diodes

This paper outlines the development of a computer vision system to enhance classification criteria for the inspection of infrared light emitting diodes (LEDs). Infrared LEDs used for fibre optics and optical switches are presently classified solely on the basis of power output. This test is performed by focusing the light beam from the LED through a circular aperture onto a solar cell. The output current from the solar cell is translated into a power output reading for the LED. The approach is limited in that it provides no information about other characteristics such as the misalignment of the beam from the mechanical centre or the intensity distribution of the beam. Improved classification criteria and testing methods based on emitted light intensity distribution can be utilised in engineering revision, setting specifications, monitoring manufacturing problems and classification for different applications.
Effective inhibition of experimental human ovarian cancers with a targeted cytotoxic bombesin analogue AN-215.

Purpose: To determine whether the cytotoxic analogue of bombesin/gastrin-releasing peptide (GRP) AN-215 can inhibit the in vivo growth of four human ovarian cancer cell lines. AN-215 consists of 2-pyrrolinodoxorubicin (AN-201), a superactive derivative of doxorubicin linked to a bombesin antagonist carrier des-D-Tpi-RC-3095. This conjugate binds strongly to receptors for bombesin/GRP and can be targeted to tumors that express these receptors. Bombesin/GRP receptors are found in 77% of human ovarian cancer specimens. Experimental Design: Nude mice bearing xenografts of ES-2, SKOV-3, OV-1063, and UCI-107 human ovarian carcinomas were treated with AN-215. The antitumor effects and the toxicity were determined. The expression of bombesin receptor subtypes was measured by reverse-transcriptase PCR analysis, and the presence of bombesin/GRP receptors was determined by radioligand binding assays. Results: AN-215 significantly ( P < 0.05) inhibited growth of ES-2, OV-1063, and UCI-107 tumors, prevented the metastatic spread of ES-2 cancers, and prolonged the survival of nude mice bearing i.p. ES-2 xenografts. Cytotoxic radical AN-201, the unconjugated mixture of bombesin antagonist RC-3095 and AN-201 or RC-3095 alone had no significant effects. Blockade of bombesin/GRP receptors abolished the effect of AN-215. The expression of bombesin/GRP receptors was not changed after repeated treatment with AN-215. Conclusions: Our findings indicate that targeted chemotherapy with cytotoxic bombesin/GRP analogue AN-215 can inhibit ovarian tumors, which express bombesin/GRP receptors. AN-215 might provide a new treatment modality for women with advanced ovarian carcinoma.
Smoking cessation for pregnant women and their partners: a pilot study.

EDITOR'S NOTE: The article featured this month emphasizes the importance of pilot studies in the implementation of nurse practitioner research. The process outlined in this article speaks to the difficulties of obtaining samples and the need to understand the population being studied. In the case of this pilot study, a great deal was learned about the proposed sample population and what might need to be done to get subjects to participate.
CHARACTERIZATION AND PHYSIOLOGIC REGULATION OF ATRIAL NATRIURETIC FACTOR RECEPTORS IN RABBIT PREGLOMERULAR RENAL MICROVESSELS

There has been no direct demonstration of the presence of guanylate cyclase-linked atrial natriuretic factor receptors in renal preglomerular microvasculature. Using [125I]ANF, we have demonstrated the presence of high affinity (Kd = 80 pM) and low affinity (Kd = 7.2 nM) ANF receptors in membranes derived from rabbit renal preglomerular microvessels (afferent arterioles and interlobular arteries). These microvessels also exhibited the presence of particulate bound ANF-sensitive guanylate cyclase. The density of the high affinity ANF receptor in desoxycorticosterone-treated rabbits on a high-salt diet (31 ± 3 fmol/mg protein) was nearly half of that seen in rabbits on a normal diet (53 ± 4 fmol/mg protein; p < 0.01, n = 4). Data from this study demonstrated the presence of renal preglomerular ANF receptors and suggested that these receptors (perhaps in addition to glomerular ANF receptors) may participate in the regulation of extracellular volume.
An experimental study of the contact mode AFM scanning capability of polyimide cantilever probes

This paper presents a preliminary exploration of high-speed contact mode performed with a polyimide probe. The probe is batch micromachined by a lithographic manufacturing process. It offers a spring constant of 7 bit resolution at 48 Hz. Scanning rates of 16 Hz (0.5mm/s) have been demonstrated for lateral force imaging with spatial resolution of 100 nm over a 15 microm scan, which translates into >7 bit resolution at 16 Hz. These results suggest that the probe can be used in high throughput applications.
Violent Crime: A Symbolic Interactionist Study*

An empirically based analysis of violent crime is presented which suggests several things. First, persons commit violent criminal acts only after theyform one of four distinct types of interpretations of the situation. Second, the self images of violent actors fall into three basic types. Third, the types of self images that they hold are linked to the types of interpretations theyform. The conclusion drawn is that persons who commit violent crimes have one of three types of generalized others.
The natural history of exercise-induced anaphylaxis: survey results from a 10-year follow-up study.

Abstract Background: Exercise-induced anaphylaxis (EIA) is a unique physical allergy that is triggered by exertion, the clinical spectrum and modifying factors of which have been previously studied. At the time of initial description, it was postulated that other factors contributed to this disorder. Objective: We sought to determine the clinical course and potential modifying factors in EIA. Methods: In 1993, we conducted a cross-sectional analysis of 671 individuals with exercise-associated symptoms for more than a decade using a validated 75-item questionnaire. Subjects met criteria for EIA if they had anaphylactic symptoms, including hypotension or upper airway obstruction, urticaria, or angioedema with physical exertion but without a passive increase in core body temperature. Results: Of 365 (54%) questionnaire respondents, 279 (87%) met criteria for EIA (199 females and 80 males). At the time of study entry, subjects with EIA (mean age, 37.5 years; range, 13 to 77 years) had an average of 10.6 years of symptoms, which were most frequently triggered by aerobic activities such as jogging or brisk walking (78% and 42%, respectively). On average, subjects reported that the frequency of attacks had decreased (47% of subjects) or stabilized (46% of subjects) since onset. One hundred (41%) subjects reported being completely free of attacks in the past year. Subjects reduced their attacks by avoiding exercise during extremely hot or cold weather (44%), avoiding ingestion of certain foods before exercise (37%), and restricting exercise during their allergy season (36%) or humid weather (33%). The most common pharmacologic agents used to manage symptoms were H1 antagonists (56%) and/or epinephrine (31%). However, 28% used no treatment at all. Conclusion: EIA is an episodic condition in which the frequency of attacks tends to stabilize or decrease over time. Improvement appears to result from individual modification of exercise and avoidance of known environmental and ingestible precipitants. (J Allergy Clin Immunol 1999;104:123-7.)
Staphylococcus aureus Protein A Recognizes Platelet gC1qR/p33: a Novel Mechanism for Staphylococcal Interactions with Platelets

The adhesion of Staphylococcus aureus to platelets is a major determinant of virulence in the pathogenesis of endocarditis. Molecular mechanisms mediating S. aureus interactions with platelets, however, are incompletely understood. The present study describes the interaction between S. aureus protein A and gC1qR/p33, a multifunctional, ubiquitously distributed cellular protein, initially described as a binding site for the globular heads of C1q. Suspensions of fixed S. aureus or purified protein A, chemically cross-linked to agarose support beads, were found to capture native gC1qR from whole platelets. Moreover, biotinylated protein A bound specifically to fixed, adherent, human platelets. This interaction was inhibited by unlabeled protein A, soluble recombinant gC1qR (rgC1qR), or anti-gC1qR antibody F(ab')(2) fragments. The interaction between protein A and platelet gC1qR was underscored by studies illustrating preferential recognition of the protein A-bearing S. aureus Cowan I strain by gC1qR compared to recognition of the protein A-deficient Wood 46 strain, as well as inhibition of S. aureus Cowan I strain adhesion to immobilized platelets by soluble protein A. Further characterization of the protein A-gC1qR interaction by solid-phase enzyme-linked immunosorbent assay techniques measuring biotinylated gC1qR binding to immobilized protein A revealed specific binding that was inhibited by soluble protein A with a 50% inhibitory concentration of (3.3 +/- 0.7) x 10(-7) M (mean +/- standard deviation; n = 3). Rabbit immunoglobulin G (IgG) also prevented gC1qR-protein A interactions, and inactivation of protein A tyrosil residues by hyperiodination, previously reported to prevent the binding of IgG Fc, but not Fab, domains to protein A, abrogated gC1qR binding. These results suggest similar protein A structural requirements for gC1qR and IgG Fc binding. Further studies of structure and function using a truncated gC1qR mutant lacking amino acids 74 to 95 demonstrated that the protein A binding domain lies outside of the gC1qR amino-terminal alpha helix, which contains binding sites for the globular heads of C1q. In conclusion, the data implicate the platelet gC1qR as a novel cellular binding site for staphylococcal protein A and suggest an additional mechanism for bacterial cell adhesion to sites of vascular injury and thrombosis.
Room-temperature 50-mJ / pulse side-diode-pumped Yb:YAG laser.

We report what to our knowledge is the highest output pulse energy to date, ~50 mJ/pulse at 15-Hz pulse repetition frequency (PRF), for a diode-pumped Yb:YAG laser. At 60-Hz PRF the 1.03-μm output beam quality was several times diffraction limited.
Charged-Particle Elastic Cross Sections

Modern treatments of energy loss in plasmas through elastic scattering of energetic ions require complete knowledge of charged-particle elastic cross sections. R-matrix theory provides an explicit separation of nuclear and Coulomb effects in these cross sections, and gives reasonable extrapolations to small angles and low energies, where data may be scarce. We outline the calculation of charged-particle elastic cross sections from R-matrix parameters, and give examples for d-T, d-α, and t-α scattering, obtained from comprehensive analyses of reactions in the 5He, 6Li, and 7Li compound systems. Expansion coefficients for an exact polynomial representation for the difference of the scattering and Rutherford cross sections (σNI) are given for d-T scattering. Integral quantities involving σNI calculated from the present cross sections disagree substantially in some cases near resonances with a recent Livermore evaluation.
Thermal Probing of E. coli RNA Polymerase Off-Pathway Mechanisms

RNA polymerase (RNAP) is an essential enzyme for cellular gene expression. In an effort to further understand the enzyme's importance in the cell's response to temperature, we have probed the kinetic mechanism of Escherichia coli RNAP by studying the force-velocity behavior of individual RNAP complexes at temperatures between 7 and 45 degrees C using optical tweezers. Within this temperature range and at saturating nucleotide concentrations, the pause-free transcription velocity of RNAP was independent of force and increased monotonically with temperature with an elongation activation energy of 9.7+/-0.7 kcal/mol. Interestingly, the pause density at cold temperatures (7 to 21 degrees C) was five times higher than that measured above room temperature. A simple kinetic model revealed a value of 1.29+/-0.05 kcal/mol for the activation energy of pause entry, suggesting that pause entry is indeed a thermally accessible process. The dwell time distribution of all observable pauses was independent of temperature, directly confirming a prediction of the model recently proposed for Pol II in which pauses are diffusive backtracks along the DNA. Additionally, we find that the force at which the polymerase arrests (the arrest force) presents a maximum at 21 degrees C, an unexpected result as this is not the optimum temperature for bacterial growth. This observation suggests that arrest could play a regulatory role in vivo, possibly through interactions with specific elongation factors.
Electromyography of wrist and finger flexor muscles in olive baboons ( Papio anubis )

Some non-human primates use digitigrade hand postures when walking slowly on the ground. As a component of an extended limb, a digitigrade posture can help minimize wrist joint moments thereby requiring little force production directly from wrist flexors (and/or from the assistance of finger flexors) to maintain limb posture. As a consequence, less active muscle volume would be required from these anti-gravity muscles and overall metabolic costs associated with locomotion could be reduced. To investigate whether the use of digitigrade hand postures during walking in primates entails minimal use of anti-gravity muscles, this study examined electromyography (EMG) patterns in both the wrist and finger flexor muscles in facultatively digitigrade olive baboons (Papio anubis) across a range of speeds. The results demonstrate that baboons can adopt a digitigrade hand posture when standing and moving at slow speeds without requiring substantial EMG activity from distal anti-gravity muscles. Higher speed locomotion, however, entails increasing EMG activity and is accompanied by a dynamic shift to a more palmigrade-like limb posture. Thus, the ability to adopt a digitigrade hand posture by monkeys is an adaptation for ground living, but it was never co-opted for fast locomotion. Rather, digitigrady in primates appears to be related to energetic efficiency for walking long distances.
NiOX/MoO3 Bi-Layers as Efficient Hole Extraction Contacts in Organic Solar Cells

The electronic structure of a bi-layer hole extraction contact consisting of nickel oxide (NiO x ) and molybdenum trioxide (MoO 3 ) is determined via ultraviolet and X-ray photoemission spectroscopy. The bi-layer presents ideal energetics for the extraction of holes and suppression of carrier recombination at the interface. The application of the NiO x /MoO 3 bi-layer as the anode of organic bulk heterojunction solar cells based on PCDTBT/PC 71 BM leads to improved device performance, which is explained by an intricate charge transfer process across the interface.
Physical Activity and Its Correlates Among Urban Primary Care Patients Aged 55 Years or Older

Objectives. Physical inactivity is a leading cause of death and disability, but very little is known about physical activity and its determinants among socially disadvantaged and medically vulnerable adults. The purpose of this study was to assess physical activity and its correlates, including measures of physical activity knowledge, perceived barriers, and self-efficacy, among socioeconomically disadvantaged older adults. Methods. A stratified random sample of 1,088 patients aged 55 years or older was selected from an urban primary care center serving a predominantly low-income population. Of the 1,088 patients sampled, 771 (71%) completed an interviewer-administered questionnaire. Results. A physical activity instrument, developed specifically for the population being studied, showed an average of 65 minutes of physical activity per week. Scores on a true-false knowledge quiz were no better than expected by chance, and over two thirds reported symptom and perceived environmental barriers to physical activity. Lower selfefficacy and greater symptom and motivational barriers were found to be associated with less physical activity. Discussion. Given the prevalence of inactivity, knowledge deficits, and perceived barriers to physical activity, population-specific interventions may be required to improve rates of physical activity among socially disadvantaged and medically vulnerable adults.