cssi/SciSciGPT-SciSciNet huggingface dataset:
Ex-Dividend Day Stock Price Behavior - The NASDAQ Evidence

We use dividend-paying Nasdaq-listed firms as a setting to test various explanations of the ex-day price anomaly. Similar to NYSE-listed firms, on average the prices of Nasdaq-listed firms drop by less than the dividend amount on the ex-day. However, the average price-drop is half that observed for NYSE-listed firms and translates to an imputed dividend tax rate that is double the average maximum tax rate over the sample period. In addition, we find the ex-day price-drop increases in dividend yield, opposite the prediction from a tax clientele explanation. Moreover, for non-taxable distributions we find prices behave in a similar manner to taxable distributions on the ex-day, again suggesting taxes are not the primary reason for the price behavior. In sum, we find little support for tax-based explanations. We also find little support for short-term trading and market microstructure explanations. Importantly, our results are robust to transaction costs as proxied by stock price, liquidity, volatility, firm size and bid-ask spread. We supplement our analysis by investigating a subset of firms that voluntarily switch from the Nasdaq exchange to the NYSE. The average price-drop for the switching firms is similar to the Nasdaq average prior to the switch and resembles the NYSE average immediately after the switch. This change in price behavior potentially reflects a changing investor base and suggests the marginal investor of Nasdaq dividend-paying firms places relatively less importance on dividends. Overall, our results call into question the various explanations of the ex-day anomaly. Any potential explanation also needs to account for the Nasdaq evidence.
Communication Costs in Digital Library Databases

Digital libraries involve various types of data like text, audio, images and video. The data objects are typically very large and of the order of hundreds and thousands of kilobytes. In a digital library, these data objects are distributed in a wide area network. Retrieving large data objects in a wide area network has a high response time. We have conducted experiments to measure the communication overhead in the response time. We have studied the correlation between communication and size of image, between communication and time of day and the communication delay to various sites in a local and wide area network. Images are amenable to losing data without losing semantics of the image. Lossy compression techniques reduce the quality of the image and reduce the size leading to a lower communication delay. We compared the communication delay between compressed and uncompressed images and studied the overhead due to compression and decompression. This enabled us to study the tradeoff between communication time and quality of the image.
A Reliability Investigation of the Eight Clinical Scales of the Suicide Opinion Questionnaire

The Suicide Opinion Questionnaire (SOQ) has been employed in a variety of settings as a measure of attitudes toward suicidal behavior. However there has been a lack of consensus across these studies with regard to the underlying factor structure of the measure. In addition there has been little empirical information reported in the literature regarding the scale's reliability. This article presents a psychometric investigation of the 8-factor clinical model of the SOQ as representing the most appropriate interpretive model for the SOQ. Factor-analytic and internal consistency reliability results failed to support the hypothesized 8-factor model. An alternative factor scheme and suggestions for future research on the SOQ are discussed.
Diagnosis and optimization of application prefetching performance

Hardware prefetchers are effective at recognizing streaming memory access patterns and at moving data closer to the processing units to hide memory latency. However, hardware prefetchers can track only a limited number of data streams due to finite hardware resources. In this paper, we introduce the term streaming concurrency to characterize the number of parallel, logical data streams in an application. We present a simulation algorithm for understanding the streaming concurrency at any point in an application, and we show that this metric is a good predictor of the number of memory requests initiated by streaming prefetchers. Next, we try to understand the causes behind poor prefetching performance. We identified four prefetch unfriendly conditions and we show how to classify an application's memory references based on these conditions. We evaluated our analysis using the SPEC CPU2006 benchmark suite. We selected two benchmarks with unfavorable access patterns and transformed them to improve their prefetching effectiveness. Results show that making applications more prefetcher friendly can yield meaningful performance gains.
Ilimaquinone Inhibits the Cytotoxicities of Ricin, Diphtheria Toxin, and Other Protein Toxins in Vero Cells

Ilimaquinone (IQ), a metabolite from sea sponges, has been shown to cause the breakdown of Golgi membranes into small vesicular structure and to inhibit protein transport without eliciting the retrograde transport of the Golgi enzymes to the endoplasmic reticulum [P. A. Takizawa, J. K. Yucel, B. Viet, D. J. Faulkner, T. Deerinck, G. Soto, M. Ellismann, and V. Malhotra, Cell (1993) 73, 1079-1090]. We have found that incubation of Vero cells with IQ inhibited the cytotoxicity of ricin in a dose-dependent manner. The inhibition was reversed upon the removal of IQ. Neither binding and internalization of 125I-ricin nor the translocation of ricin to the cytosol was affected by IQ. However, IQ significantly inhibited the recycling and degradation of internalized 125I-ricin. Preincubation with IQ also prevented the enhancement of ricin cytotoxicity by NH4Cl or nigericin. The inhibition of ricin cytotoxicity by IQ was observed in the presence of cycloheximide, indicating that de novo protein synthesis is not required for IQ-mediated protection of Vero cells from ricin cytotoxicity. In contrast to perinuclear distribution of TRITC-labeled ricin in Vero cells, TRITC-ricin appeared in numerous small vesicles dispersed throughout the cytoplasm in IQ-treated Vero cells. Double labeling with C6-NBD-ceramide and TRITC-labeled ricin showed that these ricin-containing vesicles were distinct from the IQ-induced breakdown product of the Golgi membranes. Like brefeldin A (BFA), IQ inhibited the cytotoxicities of abrin, modeccin, Pseudomonas toxin, and Shiga-like toxin in Vero cells. Unlike BFA, IQ also inhibited the cytotoxicity of diphtheria toxin (DT). Inhibition of DT cytotoxicity was the consequence of a decreased specific binding of the toxin in the IQ-treated cells.
Motor unit activity when young and old adults perform steady contractions while supporting an inertial load.

The purpose of the study was to compare the discharge characteristics of biceps brachii motor units of young and old adults when they performed steady, submaximal contractions while the arm support...
Collective excitation spectroscopy in superconductor--semiconductor tunnel junctions

The transfer-Hamiltonian description of the influence of electron-boson interactions on the electrical characteristics of metal-semiconductor tunnel junctions is extended by considering the combined effects of electrode self-energy phenomena and boson-assisted tunneling. The current associated with these processes is evaluated for superconducting metal electrodes described by the pairing model as well as for normal metal electrodes. Numerical evaluations of the conductance are made using models and parameters appropriate for the description of the influence of electron (hole) interactions with optical phonons ($\mathrm{energy}\ensuremath{\cong}\ensuremath{\hbar}{\ensuremath{\omega}}_{0}$) on the tunneling characteristics of metal contacts on boron-doped silicon.
Pattern Formation in a Substrate-Induced Phase Transition during Langmuir−Blodgett Transfer

An atomic force microscope study of Langmuir−Blodgett films deposited from the liquid expanded phase was undertaken to explore self-organizing methods of creating patterned surfaces. Although tetradecanoic (TDA), pentadecanoic (PDA), and hexadecanoic acid (HDA) monolayers deposited on silicon oxide at pH = 5.8 are uniform flat films, when the same monolayers are deposited on silicon oxide at pH = 9.3 or on mica substrates, the molecules organize into close-packed “islands”, indicative of a two-dimensional condensation. The substrate dependence of this islanding behavior suggests that surface charge plays an important role. Small islands have compact morphology, while large islands are dendritic. The length scale for the fingering instability changes by 2 orders of magnitude between TDA and HDA, from 60 nm to 6 μm.
Mechanical circulatory assistance in paediatric patients with cardiac failure

Extracorporeal membrane oxygenation (ECMO) was initially developed for respiratory failure. Its use, however, has evolved into an excellent method of preoperative and postoperative support in the treatment of infants and children with acquired and congenital heart disease. Along with ECMO, the left ventricular assist device (LVAD) and the intraaortic balloon pump (IABP) have also found a place in the management of paediatric patients with heart failure. This report documents 15 patients who were treated with one or a combination of these mechanical devices, either preoperatively or postoperatively. There is a 74% survival rate and the long-term outcome has been excellent in most cases. The use of heparin-coated devices and tight regulation of heparin has allowed the transfer of infants and children from standard cardiopulmonary bypass to assist devices in the operating room. Mechanical devices are an essential adjunct for the preoperative and postoperative treatment of infants and children with cardiac disease.
The Use of Hepatitis B Core Antibody-Positive Donor Livers Does Not Appear to Have a Deleterious Effect on Graft Survival in Liver Transplantation for Hepatitis C

Abstract Introduction The use of hepatitis B core antibody-positive donor livers (HBcAb+) has steadily increased. According to a recent multivariate analysis of United Network for Organ Sharing (UNOS) data, there was no significant increase in the risk of using these donors. The increased risk among the hepatitis C virus (HCV)-positive subgroup noted in a univariate model disappeared upon multivariate analysis. However, deeper scrutiny may show that HCV-positive recipients may be at increased risk with HBcAb+ donor livers, as they require simultaneous treatment with two antiviral regimens there may be deleterious interactions between the two viruses. Thus, the issue of HBcAb+ donors for HCV-positive recipients merits more detailed analysis. Methods Using UNOS registry data of all liver transplantations performed during the Model for End-Stage Liver Disease era from February 2002 through November 2007, we analyzed graft survival using Kaplan-Meier and Cox regression analyses. Results Of the 12,543 HCV-positive recipients, 2,543 received HBcAb− livers and 853 received HBcAb+ livers. While Kaplan- Meier analysis showed significantly lower graft survival among HCV-negative recipients of HBcAb+ livers (P = .0001), there was no significant effect on graft survival among the HCV-positive population (P = .2). To detect an early effect in HCV-positive recipients, we examined 1-year graft survival, observing no significant difference (P = .3). To exclude a possible late effect, we examined graft survival in the HCV-positive population conditional upon surviving at least 1 year after transplantation; no significant difference was observed (P = .6). The elimination of potentially confounding codiagnoses, such as hepatitis B virus, alcoholism, acute graft failure, and hepatocellular cancer did not alter the findings. On univariate analysis, the lack of a significant effect persisted among the HCV population. However, the significant effect observed in the univariate model for the HCV-negative population became insignificant when combined with other risk factors in the multivariate model. Conclusion The use of HBcAb+ livers in recipients with HCV did not appear to have a significant impact on grat survival.
Relaxation of spins due to field inhomogeneities in gaseous samples at low magnetic fields and low pressures.

We have developed a theory for the effect of magnetic-field inhomogeneities on the spin relaxation of gases in cells with negligible relaxation at the walls. There is a characteristic pressure ${p}^{\mathrm{*}}$ at which the time ${\ensuremath{\tau}}_{d}$ required for an atom to diffuse across the cell is equal to the time ${\ensuremath{\tau}}_{l}$ required for the spin to precess by one radian in the mean magnetic field. For ``high pressures,'' p\ensuremath{\gg}${p}^{\mathrm{*}}$, the longitudinal spin-relaxation time ${T}_{1}$ is inversely proportional to the pressure. This is the classic pressure dependence discussed in the literature. The new results reported in this paper are that at ``low pressures,'' p\ensuremath{\ll}${p}^{\mathrm{*}}$, the pressure dependence changes and the longitudinal relaxation time becomes directly proportional to the pressure; that is, motional narrowing occurs. We show that the transverse relaxation time ${T}_{2}$ will ordinarily be proportional to the pressure at both low and high pressures, but with different coefficients. There is also a small, pressure-dependent shift of the Larmor frequency associated with the field inhomogeneity.
Atomic force constants and apparent electron densities in elemental sulfur

Abstract The atomic force constants for sulfur in the ring compounds S6, S8 and S12 are found to be 475 ± 2 N/m, and to be transferable between these three sulfur compounds. Using a simple “atoms in molecules” model to approximate the electron density for a sulfur atom, the magnitudes of the force constant for sulfur was computed and found to be consistent with the structures of these compounds.
Effects of Freezing on the Viability of Nine Pathogens from Quarters with Subclinical Mastitis

Abstract Milk samples from 45 quarters containing mastitis pathogens were collected from lactating cows to determine the viability of those pathogens after freezing. An initial bacteria count was conducted, and samples were divided into 2-ml portions and frozen. Weekly bacteria counts were conducted for 6 wk. Viability after freezing was determined on five isolates of nine bacterial species: Staphylococcus aureus, Staphylococcus hyicus, Staphylococcus chromogenes, Staphylococcus xylosus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus, uberis, Corynebacterium bovis , and Escherichia coli . Bacteria counts were converted to logarithm base 10, and analysis of variance was conducted to determine alterations in viability over the 6-wk period. Freezing of quarter milk samples for 6 wk did not affect viability of any of these pathogens.
Smoking and Chronic Obstructive Lung Disease in Alpha1-Antitrypsin Deficiency

Similar spectra of chronic obstructive lung disease were observed in eight patients with severe and 21 with intermediate alpha1-antitrypsin deficiency, but patients with intermediate levels of protease inhibitor became ill when older and following greater cigarette exposure. In 61 presumably healthy relatives of these patients, almost one-half of those with intermediate antitrypsin deficiency who smoked had spirometric evidence of early airways obstruction. Relatives with normal antitrypsin activity did not show this change, nor were perfusion lung scan or diffusing capacity abnormalities as common in normal relatives as in deficient ones. The intermediate deficiency may predispose to lung disease by accentuating an individual's susceptibility to the harmful effects of external irritants. An interaction of genetic and environmental factors suggests that lung disease could be prevented by identifying asymptomatic, susceptible relatives and counseling them against contact with irritants. Since antitrypsin deficiency cannot be reliably recognized by any other means, we advocate that all patients with chronic obstructive lung disease undergo an antitrypsin assay.
Rehabilitation of orthopedic and rheumatologic disorders. 5. Lumbar spinal stenosis

Abstract Vo AN, Kamen LB, Shih VC, Bitar AA, Stitik TP, Kaplan RJ. Rehabilitation of orthopedic and rheumatologic disorders. 5. Lumbar spinal stenosis. This self-directed learning module highlights the pathoanatomy and pathogenesis of lumbar spinal stenosis. The areas covered include assessment and therapeutic options in the rehabilitation of patients with degenerative lumbar spinal stenosis. It is part of the study guide on rehabilitation of orthopedic and rheumatologic disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Overall article objectives (a) To summarize the evaluation and management of lumbar spinal stenosis and (b) to review the pathoanatomy and pathogenesis of lumbar degenerative spinal stenosis.
Ups and downs of adenosine

Comment on Eltzschig et al, page [1602][1] Injurious stimuli such as hypoxia and proinflammatory cytokines protect tissues from excessive inflammation by stimulating the induction of adenosine receptors and several of the enzymes that are involved in adenosine production, transport, or degradation
On the preparation of 80Br-biomolecules: 80Br-bromohippuric acid☆

A simple modification of the “direct CF3 80mBr-gas exposure” technique namely the “CF3 80mBr-gas exposure melt” method, can be successfully applied to the preparation of carrier free radiobrominated hippuric acid. This can be achieved either with hippuric acid or o-iodohippuric acid as substrates, although in the latter case 80Br-bromohippuric acid is formed in higher absolute yields and with less 80Br o-bromobenzoic acid as principal byproduct and no significant losses in 80Br-labelled product are observed if the mixture is inadvertently heated above the melting point of iodohippuric acid. Either one of these techniques requires, however, subsequent high pressure liquid chromatographic purification of the 80Br labelled substrate.
Intravenous glucose after out‐of‐hospital cardiopulmonary arrest A community‐based randomized trial

Question: Does the common practice of infusing small amounts of glucose after cardiopulmonary arrest worsen neurologic outcome? Design and setting: A community-based randomized trial in Seattle, WA. Paramedics treated all patients with out-of-hospital cardiac arrest in a standard fashion except that the intravenous infusion did or did not contain glucose; ie, patients received either usual treatment, with 5% dextrose in water (D5W), or alternative, with half normal saline (0.45S). Outcomes: The main outcome was awakening, defined as the patient having comprehensible speech or following commands as determined by chart review. Other outcomes were survival to hospital admission and to discharge. Results: Over 2 years, paramedics randomized 748 patients. The type of fluid administered was not significantly related to awakening (16.7% for D5W versus 14.6% for 0.45S), admission (38.0% for D5W versus 39.8% for 0.45S), or discharge (15.1% for D5W versus 13.3% for 0.45S). As in previous studies, patients whose arrest had likely been on a cardiac basis with initial rhythms of ventricular fibrillation or asystole had admission blood glucose levels significantly related to awakening: mean = 309 mg/dl for never awakening and 251 mg/dl for awakening. Of note, the relation between glucose and awakening was reversed in the remaining patients, who had electromechanical dissociation or noncardiac mechanisms of arrest. Conclusion: Current practices of using limited amounts of glucose-containing solutions after cardiopulmonary arrest do not need to be changed. Blood glucose level on admission is a prognostic indicator but depends on the type of arrest.
Retrograde Aortic Dissection After Bilateral Iliac Artery Stenting: A Case Report and Review of the Literature

We report a case of retrograde aortic dissection after bilateral iliac artery stenting. A 63-year-old black woman underwent aortography with balloon angioplasty of bilateral common iliac artery lesions and subsequent vascular stent placement. The patient developed an acute aortic dissection from the level of the aortic bifurcation to the left subclavian artery. This case is presented to call attention to the previously unreported complication of retrograde aortic dissection after bilateral iliac artery angioplasty and stent placement presenting as acute chest pain.
A simplified Z-1 color center calculation

Abstract A point-ion (modified by a pseudopotential) picture of the Z-1 center in alkali halides is discussed. Calculations are made using both the Seitz and Pick models. Combining our calculations with experimental measurements, we predict the values for the first excited states of the Z-1 center.
Transduction by phage P22 in a recombination-deficient mutant of Salmonella typhimurium

Abstract Recombination-deficient (Rec − ) mutants of Salmonella typhimurium were used to study special transduction by phage P22 in the absence of the usual background of general transduction. Rec − strains could not be transduced for any marker with a lysate arising by infection. When the same strains were infected with a lysate obtained by induction, low but significant levels of transduction were observed for the pro A and pro B loci (located to one side of the prophage attachment site), but not for pro C (located to the other side of the attachment site), leu , or thy . Integration-deficient ( int ) phage lysates were unable to transduce the pro A and pro B loci in Rec − cells unless int + helper phage were present. These results suggest that although Rec − cells cannot undergo general transduction, special transduction (by lysogenization) for the pro A and pro B loci is found. A mixture of int − and int + phage were unable to transduce the pro C locus despite the large number of pro C -transducing particles present in an int lysate. The inability of the int + phage genomes to promote successful lysogenization of pro C -transducing particles in Rec − cells may indicate a requirement for a structural element near the left prophage end for integration of phage P22. Alternatively, the deletion of c 2 , the structural gene for P22 repressor, from most pro C -transducing particles may prevent successful lysogenization by these particles. Finally, the pro C locus may lie too far away from the prophage site to be included in special transducing particles containing any phage DNA.
Increased Vitamin D Receptor Level Enhances 1,25-Dihydroxyvitamin D3-Mediated Gene Expression and Calcium Transport in Caco-2 Cells

Altered vitamin D receptor (VDR) level has been proposed to explain differences in intestinal responsiveness to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. We tested whether the enterocyte VDR level influences 1,25(OH)2D3-mediated gene expression and transepithelial calcium (Ca) transport in the human intestinal cell line Caco-2. Cells were stably transfected with a human metallothionein (hMT) IIA promoter-human VDR (hVDR) complementary DNA (cDNA) transgene that overexpressed hVDR in response to heavy metals. In MTVDR clones, induction of 25-hyroxyvitamin D3-24-hydroxylase (24-OHase) messenger RNA (mRNA) expression by 1,25(OH)2D3 (10(-9) M, 4 h) was correlated to metal-induced changes in nuclear VDR level (r2 = 0.99). In MTVDR clones, basal VDR level was 2-fold greater and 1,25(OH)2D3-mediated Ca transport (10(-7) M, 24 h) was 43% higher than in parental Caco-2 cells. Treatment of MTVDR clones with Cd (1 microM, 28 h) increased VDR level by 68%, significantly enhanced 1,25(OH)2D3-mediated Ca transport by 24%, and increased accumulation of calbindin D9K mRNA by 76% relative to 1,25(OH)2D3 alone. These observations support the hypothesis that the enterocyte VDR level is an important modulator of intestinal responsiveness to 1,25(OH)2D3.
Adult Education Transition Programs: A Return to Community College Access

As community colleges face increasingly tight budgets and calls for a renewed focus on improving student outcomes in the form of graduation rates, colleges must address the concept of access. How much access to higher education can they continue to provide low-skilled students in adult education and similar programs? One way to ensure access to these students is through formalized transition to college programs. The authors summarize characteristics of two transition program models and introduce research at a community college that evaluated the effectiveness of three characteristics in the models.
Agribusiness Programs in Non-Land-Grant Schools of Agriculture: Requirements for Success

the topic. Our presentation will probably be a bit different than the others, because by their titles, they have spoken from the perspective of operating academic programs at the graduate level. We are able to speak from the perspective of being responsible for the operation of undergraduate agribusiness programs as well as having managed graduate-level and adult learning experiences in the same academic area. The need to shift over to an agribusiness focus from an agricultural economics concentration has been addressed well, and at length, by respected members of the land-grant (LG) agricultural economics profession. Some have even been so bold as to suggest that unless the shift is made, and made very soon, it is only a matter of time until agricultural economics no longer exists. Others have stated that the long-run fate of entire colleges of agriculture rests on maintaining or increasing enrollments in the agribusiness and/or the agricultural economics disciplines. Most of today's students seek introductorylevel management/supervisory employment. Over the years, about half of our California students have been interested in employment in the agriculture infrastructure. They have found careers as processing plant managers, food processor field representatives, chemical sales people, transportation coordinators, domestic and international food sales managers, personnel managers, and industry and government public relations people. The other half of the agribusiness students have been about evenly divided between agricultural financial services and careers in farm or ranch (production) management operations. Generally the enrollments in agribusiness programs have depended upon the economic tone prevailing in the agribusiness sector. As noted by Thompson, Capps, and Massey, undergraduate enrollments in the agriculture and natural resource sciences grew during the 1970s and declined during the 1980s-thus paralleling the economic growth and decline of the U.S. a ricultural sector. The agricultural and natural resource areas were apparently not able to o fer competitive salaries as the agricultural economy began its downward spiral in the early 1980s. Additionally, Barkley, in his study of earnings of agricultural graduates over the 1978-88 period, showed how starting salaries followed the broader economic fortunes of the
Temporal control of urate oxidase activity during development of the third‐instar larva of Drosophila: The role of 20‐hydroxyecdysone

The tissue-specific enzyme urate oxidase is confined exclusively to the Malpighian tubules of Drosophila melanogaster and expressed only in the third-instar larva and the adult. Shortly before pupariation urate oxidase activity declines precipitously and is not detectable 24 hours later. That 20-hydroxyecdysone is the factor that triggers the disappearance of urate oxidase activity in late third-instar larvae is demonstrated using the temperature sensitive mutant ecd1 which at the nonpermissive temperature of 29°C fails to accumulate a sufficient concentration of 20-hydroxyecdysone necessary for puparium formation and thus remains a third-instar larva for 1 to 2 weeks before death. Both the life cycle and the temporal profile of urate oxidase activity in ecd1 larvae at 19°C is identical to that of the wild type. However, at 29°C ecd1 third-instar larvae retain high urate oxidase activity. A precipitous decline in urate oxidase activity is observed when ecd1 larvae at 29°C are fed 20-hydroxyecdysone. These data implicate 20-hydroxyecdysone in the process that controls the rapid decline of urate oxidase activity at the time of puparium formation. In whole homogenates of Malpighian tubules, the urate oxidase polypeptide was identified in SDS-polyacrylamide gels by its Rf with respect to homogeneously pure Drosophila urate oxidase and also by immunoprecipitation with rabbit anti-Drosophila urate oxidase IgG. Throughout development the amount of the urate oxidase polypeptide is correlated with the magnitude of urate oxidase activity.
Effect of estrogen and progesterone on the hepatic cholesterol 7α-hydroxylase activity in ovariectomized baboons

Cholesterol 7 alpha-hydroxylase activity was measured in livers from ovariectomized baboons fed a high cholesterol high saturated fat diet and maintained in four groups: untreated controls, estrogen (100 micrograms/g per week), progesterone (3 mg/kg per day) and estrogen + progesterone. Estrogen treatment alone increased hepatic 7 alpha-hydroxylase activity by 2.7-fold, whereas progesterone treatment alone did not influence hepatic 7 alpha-hydroxylase activity. The increase in 7 alpha-hydroxylase activity in estrogen + progesterone group was similar to that in the estrogen group.
Characterization in vitro of the biomechanical properties of anastomosed host artery-graft combinations

Abstract An in vitro investigation is described in which the biomechanical properties of several host artery-graft combinations are characterized under realistic hemodynamic enviornments. Canine carotid arteries served as the host vessel and were anastomosed to one of the following graft materials: 4 mm I.D. thin-walled expanded polytetrafluoroethylene (e-PTFE), 6 mm I.D. thin-walled e-PTFE, modified human umbilical vein, autogenous foreleg vein, and carotid artery. A novel feature of the experimental design is the use of a pulsatile perfusion apparatus that simulates realistic normotensive or hypertensive hemodynamics, including pulse rate, perfusion pressure, and flow rate. Measurements of dynamic transmural pressure and vessel radial motion (determined with a helium-neon laser micrometer) were obtained during pulsatile perfusion. From these data calculation of the mismatch in diameter and elasticity modulus between the host carotid artery and various graft materials is made. The longitudinal propagation of the non-uniform radial displacement associated with the construction of the anastomotic junction is also calculated and presented. The present methodology is directly applicable to testing of other vascular substitutes and provides repeatable and reliable biomechanical data. (J VASC SURG 1986;4:396-402.)
Blood Pressure in Pediatric Patients with Cushing Syndrome

Context: Hypertension (HTN) has been reported in up to 60% of children with Cushing syndrome (CS), but its course, side effects, and potential differences among various causes of CS have not been adequately studied. Objective: The objective of the study was to measure blood pressure in pediatric patients with CS before and after transphenoidal surgery or adrenalectomy and identify side effects and rates of residual HTN. Design: Data from 86 children with corticotropinomas [Cushing disease (CD)] and 27 children with ACTH-independent CS (AICS) were analyzed. Results: Patients with CD and AICS had significant HTN before surgery; more patients with AICS had systolic HTN (SHTN) than with CD (74 vs. 44%, P = 0.0077), but the rate of diastolic HTN (DHTN) was similar. Both groups experienced significant decreases in SHTN immediately after transphenoidal surgery and adrenalectomy. One year postoperatively, both SHTN and DHTN were lower than the preoperative values in all patients, but as many as 16 and 4% of the patients with CD and 21 and 5% of the patients with AICS still had SHTN and DHTN, respectively. Higher blood pressure preoperatively correlated with cortisol levels. Two patients suffered serious side effects: one with multiple infarcts and another with hypertensive encephalopathy. Conclusions: Children with CS are at risk for residual HTN despite a significant improvement after surgical cure. HTN appears to correlate with the degree of hypercortisolemia. Serious HTN-related side effects, although rare, may occur during the perioperative period.
Behind the scenes of the HGP

Future geneticists will probably reflect on the Human Genome Project (HGP) as a milestone in their field. Perhaps it will be recognized alongside the chromosome theory of inheritance, the transforming material as DNA, the double helical structure for the genetic material and the cracking of the genetic code. But the HGP has certainly distinguished itself from other landmark events in genetics not only by an absence of hypothesis-driven science but also by being mired in politics and the 'good versus evil' interplay of public access versus private enterprise. The Common Thread by John Sulston and Georgina Ferry is an intriguing portrayal of the inner workings of the HGP and the personalities involved.
An approach to selection of sustainable product improvement alternatives with data uncertainty

This paper presents a theoretical framework on the integration of simplified Life Cycle Assessment (LCA), Life Cycle Costing (LCC) and Quality Function Deployment (QFD) methodologies for the purpose of strategic selection of product improvement alternatives with consideration to data uncertainty. The research focus is on how manufacturing companies can be assisted in design of products so that quality, environmental and cost (QEC) requirements of stakeholders in the life cycle stages of the product system are addressed at an early stage where data imprecision is common. The consideration of these three design requirements leads to a multi-attribute decision situation with regard to the selection of an optimal product system improvement concept. The main objective is to develop a decision-oriented life cycle approach that integrates QEC parameters at an early stage of product development. A conceptual approach was developed which includes: (1) identification and documentation of QEC requirements' information using streamlined LCA, LCC and QFD; (2) generation of alternative concepts for product improvements and construction of sustainable concept comparison matrix where fuzzy terms were adopted to describe relationships and importance; (3) fuzzy linguistic decision support system was developed and applied to evaluate and select the optimal sustainable product improvement alternative under data uncertainty; (4) sensitivity and statistical analyses. Ranking of alternative sustainable options with respect to environment, cost and quality was reported.
Diagnostic Detection of Herpes Simplex and Hepatitis C Viral Amplicons by Capillary Electrophoresis: Comparison With Southern Blot Detection.

Background : As a result of the large number of DNA-based clinical assays, there is intense interest in making polymerase chain reaction (PCR)-amplified DNA product analysis faster, more cost-effective, and more automated. Methods and Results : In this study, an evaluation of the use of capillary gel electrophoresis with laser-induced fluorescence detection is described as a means of analyzing postamplification PCR products from clinical specimens. Sixty-six herpes simplex virus and 152 hepatitis C virus amplicons were analyzed after PCR and reverse transcription PCR, respectively. It is shown that the use of a physical gel buffer system in a short capillary in conjunction with laser-induced fluorescence detection allows for sensitive detection of herpes simplex virus- and hepatitis C virus-specific DNA fragments in an expedient manner. Interinstrument and intercapillary reproducibility of the migration time was evaluated and found to be excellent. The advantages and disadvantages over agarose gel electrophoresis-Southern blot analysis are summarized. Conclusions : The advantages offered by capillary gel electrophoresis with laser-induced fluorescent detection including rapid and sensitive analysis, ease of setup, reduced cost, and possibility for automation, make this procedure a viable alternative to more labor-intensive agarose gel electrophoresis-Southern blot analysis as molecular diagnostic methodology.
Stress incontinence alleviated by an intravaginal device

A soft doughnut-shaped device has been developed which, when inserted into the vagina, supports the tissue on each side of the upper urethra, which thereby becomes more readily reached by increases in intra-abdominal pressure. Eleven women were studied consecutively to assess the efficacy of the device. For 8 days they used absorbent pads day and night. The weight gain of the pads reflected the urine loss. The loss was determined for 4 days without the device and then for 4 days with it. The urine loss (ml/day) was 74±13.6 (mean±SE) without and 18.1±3.7 with the device, a highly significant improvement (P<0.0001). Seven women stated that the device had relieved their incontinence. However, 3 women were only slightly improved and 1 not at all.
Poly(ethylene-co-methyl acrylate)-solvent-cosolvent phase behaviour at high pressures

Abstract Cloud-point data to 160°C and 2000 bar are presented showing the effect of cosolvents on the phase behaviour of poly(ethylene- co -methyl acrylate) (EMA) ( 64 mol % 36 mol % ) with propane and chlorodifluoromethane (F22). Ethanol shifts the EMA-propane cloud-point curves to lower temperatures and pressures, but above ∼10 wt % ethanol, the copolymer becomes insoluble. Up to 40 wt% acetone monotonically shifts the EMA-propane cloud-point curves to lower temperatures and pressures. Acetone and ethanol both shift the cloud-point curves of EMA-F22 mixtures in the same monotonic manner for cosolvent concentrations of up to 40 wt%.
Optimality of process networks

Abstract Abstract In this paper we show that conservation laws for extensive quantities and the second law of thermodynamics lead to conditions for stability and optimality of a process network. Interconnections among nodes are represented through connectivity matrices and network graphs. A generalized version of Tellegen's theorem from electrical circuit theory plays a central role in deriving the objective function of the regarded dynamic process networks. The application of irreversible thermodynamics lead to stability and optimality results based on the co-content and content of the regarded process networks. The principle is illustrated in a pipeflow example.
Metamaterial Inspired Optically Transparent Band-Selective Ground Planes for Antenna Applications

This paper presents a technique for design of wideband optically transparent band-selective ground planes (BSGP) using the concept of miniaturized element frequency selective surfaces (MEFSS). The proposed multi-layer approach can provide very large bandwidth and high out of band rejection while keeping the thickness of the ground plane very low. Essentially the thickness of the ground plane made to be almost independent of the bandwidth in order to reduce its weight and sensitivity to the angle of incidence and the shape of the wavefront of the incoming radiation. As a starting point, a single pole MEFSS is studied and its performance in terms of transparency and bandwidth is compared to the traditional wire grid and transparent conductive coatings. Next, the proposed multi-pole BSGP design method is introduced and its performance is evaluated numerically and experimentally.
K 0 regeneration on deuterium

A calculation of the process ${K}_{L}^{0}d\ensuremath{\rightarrow}{K}_{S}^{0}d$ is made using the phenomenological fits of Loos and Matthews to the meson-nucleon amplitudes in the Glauber multiple-scattering formalism. The results of a numerical calculation for the scattering cross section are presented for representative values of incident kaon energy for $0\ensuremath{\le}\ensuremath{-}t\ensuremath{\lesssim}1.4$ Ge${\mathrm{V}}^{2}$.
Investigations on the effect of „light break” on the nature of the endogenous rhythm in the flowering response of Biloxi soybean ( Glycine, Max , L. merr.)

Biloxi-Soja-Bohnen (Glycine max. L. Merr) erhielten photoperiodische Cyclen, die aus 8-oder 9stundigen Lichtperioden und unterschiedlich langen Dunkelperioden bestanden. Die Dunkelperioden wurden zu verschiedenen Zeitpunkten durch halbstundiges Storlicht unterbrochen. Die Wirkung dieser unterschiedlichen Behandlungen wurde durch Messung der Bluhreaktionen bestimmt. Ein Storlicht, welches in fruhen Abschnitten der langen Dunkelperiode geboten wird, verhindert die Blutenbildung unabhangig von der Lange des Gesamtcyclus, dem die Pflanzen ausgesetzt werden. Diese Unterdruckung erreicht ihr Maximum mit einem Storlicht, welches 8 Std nach dem Beginn der Dunkelperiode wirkt; die Hemmung ist schwacher, wenn das Storlicht fruher geboten wird. Ein Storlicht, das gegen Ende der Dunkelperiode geboten wird, reduziert die Blutenbildung ebenfalls. Dieser Effekt erreicht sein Maximum mit einem Storlicht, welches ungefahr 8 Std vor dem Ende der Dunkelperiode geboten wird, er wird mit abnehmender Lange der nach dem Storlicht folgenden Dunkelperiode kleiner. Die Wirkung von Storlicht, das zu anderen Zeiten wahrend der Dunkelperiode geboten wird, hangt von der Lange des Gesamtcyclus ab. Bei Cycluslangen, die fur Blutenbildung ungunstig sind, kann solches Storlicht bluhfordernd wirken.
TU‐E‐110‐03: Inverse Geometry X‐Ray Fluoroscopy Using Scanning‐Beam Digital X‐Ray Technology

Scanning‐beam digital x‐ray (SBDX) is an inverse geometry x‐ray fluoroscopic system using a sequentially illuminated array of focal spot positions, CdTe photon‐counting detector array, and real‐time imagereconstructor. The system design substantially improves the dose efficiency of fluoroscopy by minimizing image degrading x‐ray scatter, maintaining high primary detection efficiency at high kVp, and increasing entrance field area. SBDX also has a unique real‐time tomosynthesis capability that enables 3D catheter tracking, fiducial tracking, and 3D vessel dimension analysis during procedures. Recently, image intensity equalization via adaptive reduction of beam‐on time in more transmissive patient regions has been investigated. These advanced fluoroscopic capabilities stem from a radically different x‐ ray source design. SBDX has a large‐area transmission‐style tungsten target bonded to a water‐cooled beryllium plate. A multihole collimator positioned beyond the target defines a series of narrow overlapping x‐ray beams. As the focal spot is electronically deflected from one collimator hole to the next, detectorimages are simultaneously acquired. Images of the scanning field‐of‐view are reconstructed in real time at up to 30 Hz. Design challenges include achieving sufficient x‐ray source output, fast readout rates in the detector, and the need for real‐time image reconstruction. This lecture will present the principles of the SBDX system and inverse geometry fluoroscopy. Applications of SBDX tomosynthesis and techniques used to increase signal‐to‐noise ratio and reduce heat loading in the x‐ray source will be discussed. This research was supported by NIH Grant R01 HL084022, NovaRay Medical, Inc., and Triple Ring Technologies, Inc. Learning Objectives: 1. Understand how inverse geometry x‐ray fluoroscopy design improves dose efficiency 2. Understand the operating principles of the scanning‐beam digital x‐ray system 3. Understand applications of real‐time tomosynthesis in fluoroscopically‐guided procedures
The ALFALFA CATALOG software package

Due to modern plant breeding methods, agricultural producers have many cultivars available for many different species. Consequently, it is often difficult to recommend a cultivar for a particular growing area. A list of alfalfa cultivars, germplasms, and breeding lines available was published. However, due to the large number of entries in these publications finding pertinent information about a cultivar, breeding line, or germplasm was tedious. The objectives of this project were to (i) develop a computer program to access the alfalfa information in the original database, and (ii) update the database to include those alfalfa cultivars, breeding lines, and germplasms released through late 1992. A computer program was writen using Microsoft QuickBasic, ver. 4.5 [...]
Removal of Fermentation Inhibitors Formed during Pretreatment of Biomass by Polymeric Adsorbents

The production of aldehydes that are microbial inhibitors may occur when hexoses and pentoses in an aqueous solution are exposed to temperatures above 150 °C under acidic conditions common to acid-...
Extrarenal expression of the 25-hydroxyvitamin D-1-hydroxylase

Like the vitamin D receptor (VDR), the CYP27B1-hydroxylase is expressed widely in human tissues. This expression profile establishes the potential for interaction of the VDR with the product of the CYP27B1, 1,25-dihydroxyvitamin D (1,25-(OH)(2)D), in either an intracrine or paracrine mode. This expansive expression profile also suggests that the local production and action of 1,25-(OH)(2)D to regulate VDR-directed gene expression may be similarly wide-ranging and distinct from what occurs in the kidney; the proximal renal tubular epithelial cell is the richest source of the CYP27B1 and the site for production of 1,25-(OH)(2)D destined to function as a hormone. Existence of the CYP27B1 at extrarenal sites has been widely documented, although the functional impact of the enzyme in these tissues has yet to be fully demonstrated. Two notable exceptions are the disease-activated macrophage (e.g., in sarcoidosis or tuberculosis) and the placenta. These two tissues are capable of generating enough 1,25-(OH)(2)D so as to be detectable in the general circulation. As such, this review will focus on CYP27B1 expression only at these two sites, theorizing that 1,25-(OH)(2)D production at these sites is for the purpose of local immunoregulatory function, not for controlling calcium balance in the host or the fetus.
Effects of hormone replacement therapy on serum lipids in elderly women. a randomized, placebo-controlled trial.

Background Coronary heart disease (CHD) is the leading cause of death among older women. In observational studies, the incidence of CHD has been reduced in postmenopausal women who take hormone replacement therapy (HRT). A low serum level of high-density lipoprotein (HDL) cholesterol is one of the risk factors predictive of death from CHD. Objective To determine the effects of HRT on serum lipid and lipoprotein levels in elderly women. Design Randomized, double-blind, placebo-controlled trial. Setting University research center. Participants 59 sedentary women 75 years of age or older. Intervention Participants were assigned to 9 months of oral therapy with placebo or conjugated estrogens, 0.625 mg/d, plus trimonthly medroxyprogesterone acetate, 5 mg/d for 13 days. Measurements Serum lipid and lipoprotein levels. Results After 9 months of treatment, women in the HRT group compared with women in the placebo group had decreased low-density lipoprotein cholesterol levels (mean change [+/-SD], -0.47 +/- 0.69 mmol/L [-18.2 +/- 26.5 mg/dL] vs. -0.06 +/- 0.32 mmol/L [-2.2 +/- 12.2 mg/dL], respectively; between-group difference, 0.41 mmol/L [95% CI, 0.09 to 0.74 mmol/L], 16 mg/dL [95% CI, 3.5 to 28.5 mg/dL]; P = 0.01) and increased HDL cholesterol levels (mean change, 0.21 +/- 0.27 mmol/L [8.1 +/- 10.5 mg/dL] vs. 0.06 +/- 0.11 mmol/L [2.4 +/- 4.3 mg/dL], respectively; between-group difference, 0.15 mmol/L [CI, 0.008 to 0.29 mmol/L], 5.7 mg/dL [CI, 0.8 to 10.6 mg/dL]; P = 0.02). The observed changes were independent of age at menopause onset, baseline lipid values, body weight, waist circumference, percentage body fat, and peak aerobic power. Conclusions In women 75 years of age or older, HRT improved the lipoprotein profile to the extent observed previously in younger postmenopausal women. Further studies are needed to evaluate whether these effects protect against CHD in this population.