cssi/SciSciGPT-SciSciNet huggingface dataset:
The importance of surgeon volume and training in outcomes for vascular surgical procedures

Abstract Purpose: Mortality and morbidity rates after vascular surgical procedures have been related to hospital volume. Hospitals in which greater volumes of vascular surgical procedures are performed tend to have statistically lower mortality rates than those hospitals in which fewer procedures are performed. Only a few studies have directly assessed the impact of the surgeon's volume on outcome. Therefore, the purpose of this study was to review a large state data set to determine the impact of surgeon volume on outcome after carotid endarterectomy (CEA), lower extremity bypass grafting (LEAB), and abdominal aortic aneurysm repair (AAA). Methods: The Florida Agency for Health Care Administration state admission data from 1992 to 1996 were obtained. The data included all nonfederal hospital admissions. Frequencies were calculated from first-listed International Classification of Diseases–9 codes. Multiple logistic regression was used to test the significance on outcome of surgeon volume, American Board of Surgery certification for added qualifications in general vascular surgery, hospital size, hospital volume, patient age, and gender. Results: During this interval, there were 31,172 LEABs, 45,744 CEAs, and 13,415 AAAs performed. The in-hospital mortality rate increased with age. A doubling of surgeon volume was associated with a 4% reduction in risk for adverse outcome for CEA (P = .006), an 8% reduction for LEAB, and an 11% reduction for AAA ( P = .0002). However, although hospital volume was significant in predicting better outcomes for CEA and AAA procedures, it was not associated with better outcomes for LEAB. Certification for added qualifications in general vascular surgery was a significant predictor of better outcomes for CEA and AAA. Certified vascular surgeons had a 15% lower risk rate of death or complications after CEA (P = .002) and a 24% lower risk rate of a similar outcome after AAA (P = .009). However, for LEAB, certification was not significant. Conclusion: Surgeon volume and certification are significantly related to better patient outcomes for patients who undergo CEA and AAA. In addition, surgeons with high volumes demonstrated consistently lower mortality and morbidity rates than did surgeons with low volumes. Hospital volume for a given procedure also is correlated with better outcomes. (J Vasc Surg 1999;29:768-78.)
Insulin analogues with modifications in the β-turn of the B-chain

The β-turn formed by the amino acid residues 20–23 of the B-chain of insulin has been implicated as an important structural feature of the molecule. In other biologically active peptides, stabilization of β-turns has resulted in increases in activity. We have synthesized three insulin analogues containing modifications which would be expected to increase the stability of the β-turn. In two analogues, we have substituted α-aminoisobutyric acid (Aib) for the Glu residue normally present in position B21 or for the Arg residue normally present in position B22; in a third compound, we have replaced the Glu residue with its D-isomer. Biological evaluation of these compounds showed that [B21 Aib]insulin displays a potencyca. one-fourth that of natural insulin, while [B22 Aib]insulin is less than 10% as potent. In contrast, [B21 D-Glu]insulin is equipotent with natural insulin. We conclude that the β-turn region of the insulin molecule normally possesses considerable flexibility, which may be necessary for it to assume a conformation commensurate with high biological activity. If this is the case, [B21 D-Glu]insulin may exhibit a stabilized geometry similar to that of natural insulin when bound to the insulin receptor.
Regulation of HIV-1 Gene Expression by NF-IL6

Previous studies have shown that in human T-cells (Jurkat) and hepatoma cells (HepG2), exogenous NF-IL6 can activate HIV-1 gene expression even in the absence of its consensus binding elements in the viral long terminal repeat (LTR). To identify the LTR elements that mediate this response, we have analysed constructs containing mutated and deleted LTR sequences. We have also examined heterologous plasmids to evaluate a potential requirement for the natural LTR sequences in producing HIV-1 gene activation by NF-IL6. As observed for Jurkat and HepG2 cells, we find that in the absence of NF-IL6 binding elements, NF-IL6 can elicit LTR-mediated gene expression in cotransient expression assays performed in monocytic (U937) cells. However, we detect distinct modes of regulation depending on cell type. In U937 cells, the basal LTR sequences retain a significant fraction (42%) of NF-IL6 responsiveness in the absence of upstream regulatory elements in the LTR while these elements are required for maximal response. In HepG2 cells, NF-IL6 elicits a relatively low level of gene activation from the basal LTR elements; response to NF-IL6 is restored with either the Sp1 binding sequences or the other upstream regulatory elements in the LTR. In addition, even though NF-IL6 induces a relatively low gene activity from the basal LTR sequences analysed in HepG2 cells, study of a heterologous construct indicates that these sequences are required for the responsiveness of Sp1 elements to NF-IL6 in this cellular background.
Automated microfluidic processing platform for multiplexed magnetic bead immunoassays.

A microfluidic platform is presented which fully automates all incubation steps of a three-stage, multiplexed magnetic bead immunoassay, such as the Luminex® xMAP technology. Magnetic actuation is used to transfer the microbeads between co-infused adjacent laminar flow streams to transport the beads into and out of incubation and wash solutions, with extended incubation channels to allow sufficient bead incubation times (1–30 min, commonly 5 min per stage) to enable high-sensitivity. The serial incubation steps of the immunoassay are completed in succession within the device with no operator interaction, and the continuous flow operation with magnetic bead transfer defines the incubation sequencing requiring no external fluidic controls beyond syringe pump infusion. The binding kinetics of the assay is empirically characterized to determine the required incubation times for specific assay sensitivities in the range 1 pg/ml to 100 ng/ml. By using a Luminex® xMAP duplex assay, concurrent detection of IL-6 and TNF-α was demonstrated on-chip with a detection range 10 pg/ml to 1 ng/ml. This technology enables rapid automation of magnetic microbead assays, and has the potential to perform continuous concentration monitoring.
Neonatal bacterial infection alters fever to live and simulated infections in adulthood.

Fever is a critical component of the host immune response to infection. An emerging literature demonstrates that experience with infectious organisms early in life, during the perinatal period, may permanently program immune responses later in life, including fever. We explored the influence of neonatal infection with Escherichia coli on fever responses to lipopolysaccharide (LPS) and E. coli in adulthood. Fever to a low dose of LPS in adulthood did not significantly differ as a consequence of early-life infection. Eight days after the LPS injection, the same group of rats received a high dose of live E. coli. This time, neonatally infected rats exhibited a markedly longer fever than controls. In a subsequent experiment, fever to a single high dose of E. coli without prior LPS in adulthood did not differ by group, suggesting that the previous difference was a lack of tolerance to the dual challenges in early-infected rats. Finally, both groups exhibited decreased tumor necrosis factor (TNF)-α and toll-like-receptor (TLR) 4 production to dual LPS challenges in isolated splenocytes, whereas only rats infected as neonates exhibited increased cyclooxygenase-2 within the hypothalamus in response to adult infection, suggesting that early infection-induced changes in fever regulation may involve a change in central mechanisms. Taken together, these data indicate that early-life infection is associated with marked changes in host temperature regulation in adulthood.
Parosteal osteosarcoma: case report and review of the literature.

Background. The majority of osteosarcoma cases of the head and neck are high-grade lesions. We present a case and discuss the diagnostic and therapeutic implications of a rare low-grade parosteal osteosarcoma of the maxilla. Methods. A 32-year-old man presenting to the Head and Neck Surgical Oncology clinic with a 1-year history of a firm palatal mass. Evaluation clinically and radiographically raised the suspicion of an osteosarcoma. Results. A partial maxillectomy revealed a parosteal osteosarcoma with negative margins. No adjuvant therapy was recommended, and the patient remains without evidence of local recurrence after 3 years. Conclusions. Parosteal osteosarcomas of the head and neck region are rare, low-grade variants of osteosarcoma, but have the potential to recur with simple local excision. Clinical and radiographic features are diagnostically helpful. Definitive diagnosis comes from histopathology, and wide local resection should be employed as the optimal treatment. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
UNCOUPLING OF VARIOUS MEASURES OF GROWTH IN ULVA ROTUXDATA(CHLOROPHYTA) FOLLOWING A LARGE DECREASE IN IRRADIANCE1

A vegetative clone of the chlorophyte macroalga Ulva rotundata Blid. was maintained in an outdoor continuous flow system and subjected to a large decrease in irradiance. Specific growth rates based on changes in fresh (μFW) and dry weight (μDW) and surface area (μSA) were determined using precut disks over the 24 h following a post-sunset transfer from full sunlight (100% I0) to 9% I0 All three measures of growth rate were approximately equivalent for untransferred control plants at either limiting (9%) or saturating (100%)I0. Transferred disks exhibited μFW and μSA which were slightly lower than 100%I0 controls and much higher than 9% I0 controls; μDW was nearly identical for transferred disks and 9% I0 controls. Cell size was unchanged following transfer, indicating that surface area changes reflected a proportional increase in cell number. Cell division therefore continued at a high rate for one day following transfer of U. rotundata to irradiances which are subsaturating for photosynthesis (indicated by μDw). Starch reserves were largely depleted, and the C/N ratio decreased during this period.
Mutagenesis Study of Asp-290 in Cytochrome P450 2B11 Using a Fusion Protein with Rat NADPH-Cytochrome P450 Reductase

Abstract Asp-290 of the phenobarbital-inducible dog liver cytochrome P450 (P450) 2B11 was mutated to nine other amino acid residues by site-directed mutagenesis, and the functional significance of the unique negative charge in P450 2B11 at that position was studied. To facilitate the analysis of mutated P450 2B11 enzymes heterologously expressed inEscherichia coli,an enzymatically active fusion enzyme was genetically engineered between the cDNAs for P450 2B11 and rat liver NADPH-cytochrome P450 reductase using a Ser-Thr linker as previously described (Fisheret al.,1992,Proc. Natl. Acad. Sci. USA89, 10817–10821). Sonicated whole-cell lysates ofE. colicells expressing the wild-type fusion protein were able to catalyze the 16-hydroxylation of androstenedione (AD) in the absence of added reductase, and exhibited activities and androstenedione metabolite profiles very similar to those of purified and reconstituted enzyme preparations. The substitution of Ala, Glu, Gly, Met, Asn, Arg, Ser, Thr, or Val for Asp-290 of P450 2B11 resulted in decreased AD hydroxylase activities as assessed using solubilized membranes. Replacement of Asp-290 with Glu yielded the highest activity (55% of wild type), while substituting the positively charged amino acid Arg created an enzyme with the lowest activity (
Hemozoin formation in Echinostoma trivolvis rediae.

Abstract Rediae of the trematode Echinostoma trivolvis, from naturally infected Helisoma trivolvis snails, form a black pigment while inside the snail host. Here we examine the black pigment to show that the insolubility characteristics in detergent and weak base solution are identical to Plasmodium falciparum hemozoin. Laser desorption mass spectrometry of the purified pigment demonstrates the presence of heme. Examination of purified pigment under polarized light microscopy illuminates ordered birefringent crystals. Field emission in lens scanning electron microscopy reveals irregular ovoid crystals of 200–300 nm in diameter. The purified pigment crystals seeded extension of monomeric heme onto the crystal which by Fourier Transform Infrared analysis is β-hematin. Rediae of a second echinostome parasite, Echinostoma caproni, from experimentally infected Biomphalaria glabrata, do not produce measurable or recoverable heme crystals. These observations are consistent with heme crystal formation by a hematophagous parasite within a non-vertebrate intermediate host.
Circulation and trajectories of vortex rings formed from tube and orifice openings

Abstract A model for vortex ring circulation developed by the author [P.S. Krueger, An over-pressure correction to the slug model for vortex ring circulation, J. Fluid Mech. 545 (2005) 427–443] is discussed. Numerical simulations of vortex ring formation are used to provide model closure and validation data for orifice-type generators. The model results agree well with the simulation results for both tube and orifice configurations provided the jet duration is sufficiently long. For short jets, the model discrepancy is explained in terms of an interaction between the primary and stopping vortices.
Hybrid Gas-Liquid Electrical Discharge Reactors for Organic Compound Degradation

A gas−liquid hybrid pulsed corona discharge reactor that utilizes high voltage needle-point electrodes submerged in the aqueous phase coupled with planar ground electrode suspended in the gas phase above the water surface has been developed and analyzed for the removal of low concentrations of phenol. Two types of ground electrodes were evaluated. One type consisted of a solid disk made of stainless steel, and the second type consisted of a disk made of high porosity reticulated vitreous carbon (RVC). The liquid-phase discharge leads to the formation of hydrogen peroxide and hydroxyl radicals, and the gas-phase discharge leads to the formation of ozone. The reticulated carbon electrode produced a higher number and more uniform distribution of plasma channels in the gas phase above the liquid surface. This case also led to the largest amount of ozone dissolved in the liquid phase. The combined action of the reactive species formed in the gas and the liquid phases on the degradation of phenol, the formation...
Thallous chalcogenide (Tl6I4Se) for radiation detection at X-ray and γ-ray energies

Abstract The optical and charge transport properties of the thallous chalcogenide compound Tl 6 I 4 Se were characterized. The semiconductor crystals are grown by the modified Bridgman method. We have measured the refractive index, and absorption coefficient of the compound ranging from 300 to 1500 nm by analysis of the UV–vis–near IR transmission and reflection spectra. The band gap is 1.8 eV. For the evaluation of detector performance, the mobility-lifetime products for both the electron and hole carriers were measured. Tl 6 I 4 Se has mobility-lifetime products of 7.1×10 −3 and 5.9×10 −4 cm 2 /V for electron and hole carriers, respectively, which are comparable to those of Cd 0.9 Zn 0.1 Te. The γ-ray spectrum for a Tl 6 I 4 Se detector was measured. Its response to the 122 keV of 57 Co source is comparable to that of Cd 0.9 Zn 0.1 Te.
Polysiloxane-based scintillators: 1,1,44-tetraphenylbutadiene

Abstract A new polysiloxane-based plastic scintillator with substituted oligophenylene and tetraphenylbutadiene as a primary and secondary fluor, respectively, has been suggested. These dyes show excellent spectral properties and fluorescence decay time, and overall radiation stability of the scintillator is very good. The final scintillator appears suitable for use at the Superconducting Super Collider.
TONIC RETINAL INFLUENCES IN PRIMATES

A type of unit discharge, termed "luxotonic," has been found in the striate cortex of unanesthetized squirrel monkeys and macaques.6, 21 The firing frequency of these units shows relatively little adaptation, continues indefinitely (hours), and reflects the level of diffuse illumination of the eye. The more numerous "photergic" units discharge more rapidly in the light, whereas "scotergic" units fire fastest in the dark (or at luminance levels below threshold for cones). Luxotonic activity is abolished by anesthesia and has not been described for striate cortex of other species. Primates also display a profound alteration in the EEG of striate cortex following elimination of all retinal input.32 Since this change is far more drastic than that produced by blindness in other species, it is natural to inquire whether it is related to the loss of the normally prominent luxotonic activity. When the blind monkey sleeps, the bizarre EEG is replaced by patterns wholly normal in appearance,32 indicating that some nonvisual system has extensive access to striate cortex in this state.
Whiteness and the Polarization of American Politics

Scholars tend to agree that American politics has become polarized along partisan and ideological lines, yet the causes of polarization are in much dispute. The author argues that polarization and the culture wars are a consequence, in part, of the changing nature of white identity after the civil rights movement. The transformation of whiteness from a form of social standing to a norm produced ressentiment among whites, which Republican strategists mobilized by depicting Democrats as the party of intellectual snobs and undeserving rabble and the GOP as the party of the virtuous middle. Normalizing this middle and the snobs as white polarized whites along partisan and ideological lines, creating an incentive to win votes by appealing to hot-button cultural issues such as welfare, abortion, and gay marriage.
Poly(ethyleneimine) infused and functionalized Torlon®-silica hollow fiber sorbents for post-combustion CO2 capture

Abstract Organic–inorganic hybrid materials functionalized with amine-containing reagents are emerging as an important class of materials for capturing carbon dioxide from flue gas. Polymeric silica hollow fiber sorbents are fabricated through the proven dry-jet/wet-quench spinning process. In our study, a new technique for functionalizing polymeric silica hollow fiber sorbents with poly(ethyleneimine), followed by a post-spinning infusion step was studied. This two step process introduces a sufficient amount of poly(ethyleneimine) to the polymeric silica hybrid material support to improve the CO2 sorption capacity due to the added amine groups. The poly(ethyleneimine) infused and functionalized hollow fiber sorbents are also characterized by a thermal gravimetric analyzer (TGA) to assess their CO2 sorption capacities.
Patient-controlled analgesia in children and adolescents: a randomized, prospective comparison with intramuscular administration of morphine for postoperative analgesia.

A randomized, prospective trial of patient-controlled analgesia (PCA), that is, a method of analgesia administration involving a computer-driven pump activated by patients to receive small doses within defined limits, was performed in 82 children and adolescents after major orthopedic surgery to compare (1) intramuscularly administered morphine, (2) PCA morphine, and (3) PCA morphine with a low-dose continuous morphine infusion (PCA-plus). Patients receiving PCA and PCA-plus had lower pain scores and greater satisfaction than patients receiving intramuscularly administered morphine. The three groups used equal amounts of morphine and most measures of recovery were identical in the groups. In particular, PCA and PCA-plus did not increase the incidence of opioid-related complications, and patients receiving PCA-plus were less sedated than patients receiving intramuscular therapy. We conclude that PCA and PCA-plus are safe and effective methods of pain relief in children and adolescents after orthopedic surgery, are better accepted than intramuscular injections, and do not increase perioperative morbidity.
Regional Real-Time Numerical Weather Prediction: Current Status and Future Potential

During the past several years, regional numerical prediction efforts have proliferated as local computer power increased, mesoscale modeling systems became easier to use and more readily available, and model analyses and forecasts from national centers became increasingly accessible over the Internet. This paper surveys real-time numerical forecasting efforts around the country, reviews the conclusions of two recent workshops on the subject, evaluates the role of local real-time weather prediction, and suggests future cooperative efforts.
MASS TRANSFER OF CO2 ACROSS MEMBRANES: FACILITATION IN THE PRESENCE OF BICARBONATE ION AND THE ENZYME CARBONIC ANHYDRASE

SUMMARY A theoretical and experimental analysis of facilitated transport of CO2 across membranes containing NaHCO3 and the enzyme carbonic anhydrase (carbonate hydro-lyase EC 4.2.1.1) is presented. The necessary diffusion reaction equations are derived and the system constraints defined. For the CO2-HCO3- system, mathematical simplifications based on the magnitude of various reaction and concentration terms are made to make the equations tractable to solution. The resultant equations are solved by a number of analytical and numerical techniques, each having a limited, though useful, range of validity. The experimental arrangement consists of a liquid membrane (created by soaking a porous filter paper in the test solution), a diffusion chamber, and gas metering and analysis equipment. Conditions were selected to cover the range from diffusionto reaction-dominated behavior. The flux of CO2 across a membrane containing ! M NaHCO3 was measured at various partial pressures of CO2 (2-28 in Hg) and with membrane thicknesses of 0.02, 0.06 and 0.10 cm. The extent of facilitation (defined as the ratio of reactionrelated flux to the expected Fick's Law flux in the absence of reaction) ranged from near zero to nearly 5 in these experiments. The agreement between model calculations and experimental observation was found to be excellent over the entire range of neardiffusion to near-equilibrium behavior. In the presence of enzyme carbonic anhydrase (0.10 mg/ml, activity approx. 80%) and 1 M NaHCO3, the CO2 flux across a 0.02 cm membrane was 3-10-fold higher than the corresponding flux in the absence of enzyme. From experiments at various enzyme concentrations and membrane thicknesses, it appeared that the apparent CO2 reaction rate was directly proportional to the enzyme concentration. The model calculations for the enzyme-catalyzed reactions agreed with the experimental observations to within ± 10 %.
[18F]Fluorodeoxyglucose uptake by positron emission tomography for diagnosis of suspected lung cancer: impact of verification bias.

Background Verification bias occurs when test findings influence the decision to perform a gold standard test. It adversely influences diagnostic test accuracy by inflating sensitivity and deflating specificity. We studied the impact of verification bias on the estimated accuracy of a test commonly used in suspected lung cancer. Methods We studied 534 consecutive patients referred for [ 18 F]fluorodeoxyglucose uptake by positron emission tomography (PET). Primary outcomes were tissue diagnoses of cancer and of mediastinal lymph node metastases. A secondary outcome was 3-year mortality. We accounted for verification bias using 2 validated methods. Results The gold standard test, namely tissue acquisition, was performed in 419 patients (78%); mediastinal lymph node sampling occurred in 301 (56%). While the 410 patients with PET-diagnosed stage I cancer or higher were more likely than patients with negative PET scan findings to undergo tissue diagnosis testing (92% vs 34%) ( P P Conclusion The diagnostic accuracy of PET for assessment of suspected lung cancer is substantially affected by verification bias.
Health as situational adaption: A social psychological perspective

Abstract A model to encompass the complex relationship between the individual and his social, physical and cultural environments and to provide strategies for intervention has not yet been developed. While professionals acknowledge the importance of an ecological and holistic conception of man-environment interaction, various biases and ideologies prevent them from adequately taking this interaction into account. To overcome this inadequacy this paper explores a relational conception of health, the central importance of the socially defined situation for health and adaption, the limits of medicine and holism in intervening in problems of adaption and suggests a situational approach to the study of health and adaption. By stressing the socially defined situation and the social psychological actor it may be possible to sensitize the actor to socially situated man-environment transactions, to preserve the actor's confidence in his own health, to encourage individual responsibility for maintaining health and to promote an awareness of signs and symptoms that require medical attention. Within a larger framework, however, it is not effective to intervene in the individual's social situations if we do not also attempt to alter the macro economic, political, cultural and structural elements in society which encourage, produce and support unhealthy environmental conditions.
Relapse Prevention in Childhood Depression

For many years, childhood depression was underdiagnosed and undertreated. Now it is recognized as a significant mental health problem. For example, suicide is a leading cause of death among adolescents. As a result, there has been increased interest in how to diagnose and treat depression in children and adolescents. Initially, diagnosis and treatment were extrapolated from studies of depressed adults. Although this approach was somewhat successful, there are differences between depressed children/adolescents and depressed adults. Thus, studies that directly assess depressed children and adolescents are needed. In depressed adults, research has indicated that cognitive-behavioral therapy (CBT) and pharmacotherapy are effective in alleviating symptoms of depression. These two treatment modalities also have been used in children and adolescents. Early studies in this age group also found these therapies to be effective. Perhaps the best known treatment study of adolescent depression has been the Treatment of Adolescent Depression Study (TADS) [1]. In this study, fluoxetine treatment alone, CBT alone, a combination of fluoxetine and CBT, and placebo were compared in depressed adolescents. The primary results showed that combined fluoxetine and CBT treatment and fluoxetine treatment alone were better than placebo; and combined treatment was better than fluoxetine alone. However, in this study, CBT alone was not statistically better than placebo. Since the publication of this study, there has been ongoing discussion of how to combine CBT and medication to produce the best treatment results. Of particular concern has been the high relapse rate among successfully treated children and adolescents. A question that remains unanswered is what kind(s) of treatment(s) will prevent or delay relapse after a patient has responded to acute treatment? The authors indicated that the relapse rate after successful acute phase pharmacologic and psychosocial treatments of childhood major depressive disorder ranged from 34% to 75% [2]. Thus, they decided to assess the effect of adding CBT for children and adolescents who responded to acute treatment with fluoxetine to prevent the relapse/ recurrence of depressive symptoms.
Clinical evaluation and management of work-related carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is a clinical entity characterized by pain, paresthesias, and numbness in the distribution of the median nerve with weakness and atrophy of the thenar muscles in advanced cases. It is universally accepted that CTS is the clinical concomitant of compression of the median nerve as it passes through the carpal canal. It is reported to be the most common of the entrapment neuropathies. Increasing evidence suggests that occupational factors, including forceful use of the hands, repetitive use of the hands, and hand-arm vibration, are etiologic for CTS. When occurring as a result of occupational exposures, the term "work-related carpal tunnel syndrome" is applied. Clinical approaches to the diagnosis and treatment of work-related CTS are described in this paper. Particular attention is paid to the clinical features and pathophysiology of CTS, the epidemiology of work-related CTS, ascertainment of work-relatedness in the clinical setting, treatment including both work and non-work interventions, and control of occupational ergonomic risk factors that may contribute to the illness.
Dynamic Study of Crystallization- and Melting-Induced Phase Separation in PEEK/PEKK Blends

Kinetics of lamellar microstructure development of poly(aryl ether ether ketone) (PEEK), poly(aryl ether ketone ketone) containing 70% isophthalate moieties (PEKK(30/70)) and their 50/50 blend duri...
Trial and Repeat Buying—The Case for Separate Consideration:

Consumer panel purchase data for several new brands are anllyzed, focusing on macrobehavioral characteristics of two groups: triers and repeat buyers. Theoretical analysis and supporting empirical evidence suggest that the two groups differ markedly in purchasing behavior. Implications for product life cycle theory and marketing practice are discussed.
Defending against Big Dada: Defensive Tactics for Weapons of Mass Deception

The first casualty of power politics, advocacy journalism, dark propaganda, rumor mills, and media-politico echo chambers is truth. Here's a defensive tactic for your consideration.
Student expectations of computing majors

This paper describes research into student motivation and satisfaction with various computing majors on campus. A survey was administered to 422 computing majors and a different survey was administered to approximately 800 non-computing majors at Brigham Young University. The objective was to discover student understanding and expectations of the Computer Science, Information Systems and Information Technology programs on campus. Students within these majors were asked about their satisfaction and career expectations and non-computer majors were asked about their understanding of the computing majors. Motivations for selecting specific majors were explored. Recommendations are made for helping students select the most appropriate computing major for their needs.
Dr. Andrew Huvos (1934–2006) Retrospective: A Tribute to the Pathologist and the Man

Andrew G. Huvos was born in communist Budapest, Hungary, in March of 1934. At twenty-four he immigrated to New York City, working as a cytotechnologist at Delafield Hospital. Dr. Huvos attended the University of Gottingen Medical School in Germany, where he was awarded his MD degree. He completed a 1-year internship at New York Hospital, going on to Residency at Delafield Hospital and Fellowship at Presbyterian Hospital. Dr. Huvos ascended through the ranks to Attending Pathologist and Member at Memorial Hospital for Cancer and Allied diseases, at Memorial Sloan-Kettering Cancer Center (MSKCC) in New York City. Concurrently, he was appointed to Weill Medical College of Cornell University, where he was Professor of Pathology for over two decades. Dr. Huvos was an editorial referee for over half a dozen highly esteemed publications, including the New England Journal of Medicine and Cancer. He trained over a thousand oncological surgical pathology fellows, head and neck fellows, and surgeons. Dr. Huvos spent nearly 40 years at MSKCC and his career was accompanied by his authorship of 388 peer-reviewed publications and eighteen book chapters. His legacy leaves behind a generation of pathologists who have greatly benefited from his tutelage.
The effect of repeated microwave heating, fill level and temperature on the impact resistance of a polypropylene syrup bottle

The effect of repeated microwave heating, fill level/and storage temperature on the impact resistance of microwavable polypropylene bottles containing syrup was studied. Bottles filled with syrup at 100%, 75%, 50%, and 25% levels were subjected to drop tests after storage at 8°C, 20°C/and 40°C and after several reheatings in a conventional microwave oven following the label directions. The degree of crystallinity of the polypropylene was also evaluated using modulated DSC. A decrease in impact resistance and an increase in the degree of crystallinity of the package material was observed after the bottles were repeatedly heated in the microwave oven. Impact orientation, product fill level and storage temperature also significantly affected the impact resistance of the bottles. The bottle impact resistance may be insufficient for the intended use. Copyright © 2000 John Wiley & Sons, Ltd.
Oxygen-tolerant coenzyme A-acylating aldehyde dehydrogenase facilitates efficient photosynthetic n-butanol biosynthesis in cyanobacteria

Metabolic engineering of photosynthetic microorganisms such as cyanobacteria for the production of fuels or chemicals is challenging, particularly when the pathway involves oxygen-sensitive enzymes. We have previously designed a coenzyme A (CoA) dependent n-butanol biosynthesis pathway tailored to the metabolic physiology of the cyanobacterium Synechococcus elongatus PCC 7942 by incorporating an ATP driving force and a kinetically irreversible trap. However, one of the enzymes involved, CoA-acylating butyraldehyde dehydrogenase (Bldh) is oxygen sensitive, therefore hindering efficient n-butanol synthesis in cyanobacteria. To overcome this obstacle of n-butanol biosynthesis, we characterized six oxygen tolerant CoA-acylating aldehyde dehydrogenases (PduP) from the 1,2-propandiol degradation pathway for their activity toward acyl-CoA. We showed that PduP catalyzes the reversible reduction of a broad range of acyl-CoAs (C2 to C12) into corresponding aldehydes. In particular, PduP from Salmonella enterica has the highest catalytic efficiency (kcat/Km) of 292 s−1 mM−1 for butyryl-CoA, which is about 7 times higher than that for acetyl-CoA. Finally, replacing Bldh with PduP in the n-butanol synthesis pathway resulted in n-butanol production to a cumulative titer of 404 mg L−1 with peak productivity of 51 mg per L per day, exceeding the base strain by 20 fold. Thus, the oxygen sensitivity of CoA-acylating aldehyde dehydrogenase appears to be a key limiting factor for cyanobacteria to produce alcohols through the CoA-dependent route.
The Study of Macromolecular Dynamics by High Resolution NMR

The measurement and interpretation of relaxation data on macromolecules present special problems. The required instrumental conditions and extensions of relaxation theory are outlined and illustrated by the analysis of 13C and 1H relaxation data on a small protein (bovine pancreatic trypsin inhibitor).
A quadratically convergent primal-dual algorithm with global convergence properties for solving optimization problems with equality constraints

This paper presents a globally convergent multiplier method which utilizes an explicit formula for the multiplier. The algorithm solves finite dimensional optimization problems with equality constraints. A unique feature of the algorithm is that it automatically calculates a value for the penalty coefficient, which, under certain assumptions, leads to global convergence.
Repeating Words in Spontaneous Speech.

Abstract Speakers often repeat the first word of major constituents, as in, “I uh I wouldn't be surprised at that.” Repeats like this divide into four stages: an initial commitment to the constituent (with “I”); the suspension of speech; a hiatus in speaking (filled with “uh”); and a restart of the constituent (“I wouldn't . . .”). An analysis of all repeated articles and pronouns in two large corpora of spontaneous speech shows that the four stages reflect different principles. Speakers are more likely to make a premature commitment, immediately suspending their speech, as both the local constituent and the constituent containing it become more complex. They plan some of these suspensions from the start as preliminary commitments to what they are about to say. And they are more likely to restart a constituent the more their stopping has disrupted its delivery. We argue that the principles governing these stages are general and not specific to repeats.
Effect of Optical Surface Properties on High-Temperature Solar Thermal Energy Conversion

The effects of thermal surface properties on the performance of representative point-focusing solar power plants are assessed in this paper. The tradeoff relationships are presented in terms of normalized system performance as a function of thermal optical design parameters. Crucial surface properties include solar reflectance, specular spreading due to microscopic roughness, surface error due to manufacturing slope tolerance or waviness, and concentrator pointing accuracy. Two representative power conversion systems, a Rankine steam cycle and an open-air Brayton cycle, are considered.
Product Development and Pricing Strategy for Information Goods Under Heterogeneous Outside Opportunities

This paper considers a two-stage development problem for information goods with costless quality degradation. In our model, a seller of information goods faces customers that are heterogeneous with regard to both the marginal willingness to pay for quality and the outside opportunity. In the development stage, the seller determines the quality limit of the product. In the second stage, the seller's problem is to design the price schedule corresponding to different quality levels, taking into account production and distribution costs. We show that versioning is optimal for the seller when customers have multiple outside options or, more generally, convex reservation utilities. In addition, we show that in the optimal solution the seller discards both low-end and high-end customers. Among those that are served, the seller offers a continuum of (inferior) versions to customers with relatively low willingness to pay, and extracts full information rent from each of them. A common version with the quality limit is offered to the rest. We further prove that the seller should offer a single version when reservation utilities are either concave or linear. Through numerical experiments, we study the sensitivity of our results to changes in the cost structure and customer utilities.
In situ detection of alkaline nuclease activity in cells infected with herpes simplex virus type 1 (HSV-1)

Abstract An in situ assay for detection of alkaline nuclease activities has been adapted to the herpes simplex virus type 1 (HSV-1) system. Six major nuclease activities which migrate with molecular weights of 90 000, 85 000, 80 000, 76 000, 71 000 and 65 000, and six minor species of molecular weights 87 000, 81 000, 57 000, 18 500, 17 500 and 16 500 were detected in lysates of HSV-1 infected cells following SDS-polyacrylamide gel electrophoresis and enzyme activation in situ. An ELISA assay and an immunoprecipitation study indicated that the six major HSV-induced nuclease species are virus-specific. Moreover, a reconstruction experiment in which 14 C-labelled protein markers were incubated with mock- and HSV-infected cell lysates demonstrates that the nuclease fractions detected in situ were not due to endogenous proteolytic activity. The 80 000, 76 000, 71 000 and 65 000 species were first detected at 4 h post-infection, whereas all others were detectable by 6 h post-infection. The activities of the major cellular nucleases of molecular weights 50 000. 48 000 and 45 000 decreased as a function of time post-infection. The level of expression of each of the virus-induced species was dependent upon the multiplicity of infection, and all virus-induced activities exhibited biochemical properties characteristic of purified HSV-1 alkaline nuclease, including activation and inhibition by specifications. The 76 000 HSV-induced alkaline nuclease species was also demonstrated to possess endonucleolytic activity.
GLYCOGEN DEPOSITION IN ADIPOSE TISSUE: VARIATIONS IN LEVELS OF GLYCOGEN-CYCLE ENZYMES DURING FASTING AND REFEEDING.

Abstract The influence of fasting and fasting-refeeding upon the activities of the glycogen-cycle enzymes in rat epididymal adipose tissue has been investigated. In fed (control) animals UDPG-glycogen transglucosylase is the limiting enzyme in the pathway between glucose and glycogen in adipose tissue. Fasting for 48 hours significantly lowered the levels of all of the enzymes of the glycogen cycle, and refeeding of a low-fat, high-carbohydrate diet for either 24 or 48 hours following a 48-hour fast resulted in an apparent sequential return of the enzyme activities in the order in which they appear in the glucose to glycogen pathway. Endogenous glucose-6-phosphate levels in adipose tissue during the various nutritional states were not significantly different from the fed state, and thus the activation of UDPG-glycogen transglucosylase by glucose-6-phosphate apparently does not account for the marked deposition of glycogen which occurs during refeeding.
A Matching Algorithm to Address Imbalances in Study Populations: Application to the National Institute of Neurological Diseases and Stroke Recombinant Tissue Plasminogen Activator Acute Stroke Trial

Background and Purpose— Outcome from stroke is highly dependent on baseline conditions. Patients with stroke have a wide range of severities, ages, and etiologies and it has proven difficult to achieve randomization of key variables in clinical trials. We present a new post hoc approach to achieve balance among selected variables. To illustrate the approach, we rebalanced the National Institute of Neurological Diseases and Stroke Recombinant Tissue Plasminogen Activator trial, in which the contribution of baseline imbalances continues to be debated. Methods— We selected baseline stroke severity (National Institutes of Health Stroke Scale), age, and glucose as matching criteria. The closest matched placebo and treated subjects were identified based on nearness to each other in 3-dimensional Euclidean space. Matching was performed within the quintiles of National Institutes of Health Stroke Scale that have been previously used to assess balance. Subjects who could not be matched were eliminated. Outcomes we...
Phototropism of Arabidopsis thaliana in microgravity and fractional gravity on the International Space Station.

While there is a great deal of knowledge regarding plant growth and development in microgravity aboard orbiting spacecraft, there is little information available about these parameters in reduced or fractional gravity conditions (less than the nominal 1g on Earth). Thus, in these experiments using the European Modular Cultivation System on the International Space Station, we studied the interaction between phototropism and gravitropism in the WT and mutants of phytochrome A and B of Arabidopis thaliana. Fractional gravity and the 1g control were provided by centrifuges in the spaceflight hardware, and unidirectional red and blue illumination followed a white light growth period in the time line of the space experiments. The existence of red-light-based positive phototropism in hypocotyls of seedlings that is mediated by phytochrome was confirmed in these microgravity experiments. Fractional gravity studies showed an attenuation of red-light-based phototropism in both roots and hypocotyls of seedlings occurring due to gravitational accelerations ranging from 0.l to 0.3g. In contrast, blue-light negative phototropism in roots, which was enhanced in microgravity compared with the 1g control, showed a significant attenuation at 0.3g. In addition, our studies suggest that the well-known red-light enhancement of blue-light-induced phototropism in hypocotyls is likely due to an indirect effect by the attenuation of gravitropism. However, red-light enhancement of root blue-light-based phototropism may occur via a more direct effect on the phototropism system itself, most likely through the phytochrome photoreceptors. To our knowledge, these experiments represent the first to examine the behavior of flowering plants in fractional or reduced gravity conditions.
Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome

Recent investigations suggest a role for neurally mediated hypotension (NMH) in the symptomatology of chronic fatigue syndrome (CFS) in adults. Our previous observations in children with NMH and syncope (S) unrelated to CFS indicate that the modulation of sympathetic and parasympathetic tone measured by indices of heart rate variability (HRV) is abnormal in children who faint during head-up tilt (HUT). In order to determine mine the effects of autonomic tone on HUT in children with CFS we performed measurements of HRV during HUT in 16 patients aged 11–19 with CFS. Data were compared to 26 patients evaluated for syncope and with 13 normal control subjects. After 30 minutes supine, patients were tilted to 80° for 40 minutes or until syncope occurred. Time domain indices included RR interval, SDNN, RMSSD, and pNN50. An autoregressive model was used to calculate power spectra. LFP (.04–.15 Hz), HFP (.15–.40Hz), and TP (.01–.40Hz). Data were obtained supine (baseline) and after HUT. Thirteen CFS patients fainted (CFS+, 5/13 pure vasodepressor syncope) and three patients did not (CFS-). Sixteen syncope patients fainted (S+, all mixed vasodepressor-cardioinhibitory) and 10 did not (S-). Four control patients fainted (Control+, all mixed vasodepressor-cardioinhibitory) and nine did not (Control-). Baseline indices of HRV were not different between Control+ and S+, and between Control- and S-, but were depressed in S+ compared to S-. HRV indices were strikingly decresed in CFS patients compared to all other groups. With tilt, SDNN, RMSSD, and pNN50 and spectral indices decreased in all groups, remaining much depressed in CFS compared to S or control subjects. With HUT, sympathovagal indices (LFP/HFP, nLFP, and nHFP) were relatively unchanged in CFS, which contrasts with the increase in nLFP with HUT in all other groups. With syncope RMSSD, SDNN, LFP, TP, and HFP increased in S+ (and Control+), suggesting enhanced vagal heart rate regulation. These increases were not observed in CFS+ patients. CFS is associated with NMH during HUT in children. All indices of HRV are markedly depressed in CFS patients, even when compared with already low HRV in S+ or Control+ patients. Sympathovagal balance does not shift toward enhanced sympathetic modulation of heart rate with HUT and there is blunting in the overall HRV response with syncope during HUT. Taken together these data may indicate autonomic impairment in patients with CFS.
Roles of local classical acceleration and spatial separation in the neutral particle analogs of the Aharonov-Bohm phases.

I show that neither local nonuniform classical acceleration nor spatial separation of the quantized spin components plays an essential role in a number of neutron interferometer experiments designed to detect phases [phi][sub [plus minus]]([ital B],[ital E]) akin to the Aharonov-Bohm phases. These neutral particle phases, which simply manifest quantum interference in spin space, can also be detected by single beams, as exemplified by a recent breakthrough experiment by Sangster [ital et] [ital al].