cssi/SciSciGPT-SciSciNet huggingface dataset:
The influence of halothane, isoflurane, and pentobarbital on cerebral plasma volume in hypocapnic and normocapnic rats.

Cerebral blood volume (CBV = cerebral plasma volume [CPV] + cerebral red cell volume [CRBCV]) is one determinant of intracranial pressure. In an effort to quantitate the effects of anesthetics and PaCO2 on CBV, the authors measured cerebral plasma volume (CPV) in normocapnic (PaCO2 approximately 42 mmHg) and hypocapnic (PaCO2 approximately 22 mmHg) rats receiving 1 MAC doses of isoflurane or halothane, or given an approximately equivalent dose of pentobarbital. All animals were paralyzed, their lungs mechanically ventilated, and body temperature kept normal throughout the study. CPV was measured using 14C-labeled dextran, a large (70,000 molecular weight [M.W.]), nondiffusible compound that was given intravenously and allowed to circulate for approximately 5 min. The experiments then were terminated by freezing the brains in situ with liquid N2 poured into a funnel affixed to the exposed calvarium. Isotope concentrations in solubilized brain and in plasma were determined by scintillation counting, and CPV was calculated as the ratio between these values. CPV during both hypocapnic and normocapnic pentobarbital anesthesia was less than with either volatile agent. During normocapnia, CPV for pentobarbital = 2.1 +/- 0.26 ml/100 g (mean +/- SD, n = 8), compared with 2.96 +/- 0.44 ml/100 g (n = 9) and 3.06 +/- 0.44 ml/100 g (n = 9) for halothane and isoflurane, respectively. There were no differences in CPV between the two volatile agents during normocapnia.(ABSTRACT TRUNCATED AT 250 WORDS)
Leukemia in pregnancy and fetal response to multiagent chemotherapy

Abstract Background: Leukemia is rare in pregnancy and treatment with intensive, multiagent chemotherapy produces complete remission in most adults, but might have deleterious effects on fetuses. Case: A 24-year-old gravida 3 para 2 presented at 24 weeks with pruritus, rash, pancytopenia, and hepatitis. A bone marrow biopsy found acute lymphocytic leukemia. She completed three cycles of intensive multiagent chemotherapy with transient oligohydramnios in each cycle. Although there was decreased fetal growth rate, umbilical artery Doppler scans were normal. She delivered a normal 2150-g male infant at 36 weeks. Conclusion: Pregnant women with newly diagnosed leukemia should not delay treatment, but multiagent chemotherapy might have transient effects on fetuses, most notably oligohydramnios. However, if fetal testing is normal, delivery might not be indicated.
Population level processes in Rhizobium leguminosarum bv. trifolii: the role of founder effects

The importance of genotype-specific selection between host and symbiont, founder effect, and clonal reproduction in Rhizobia leguminosarum biovar trifolii populations is relatively unknown. A field experiment was conducted to sample 1268 isolates of R. l. bv. trifolii from four genotypically distinct Trifolium pratense plants for allozyme variation at nine loci. Genetic and genotypic variation, population genetic substructure, and linkage disequilibrium were estimated. Of the 1268 isolates 188 genotypically distinct strains (electrophoretic types or ETs) were identified with an average of 11.04 different ETs per plant. Total genetic diversity in the plot was 0.346 and most of the variation was found within plants (= 80%). Our data suggests that genotype-specific selection between the rhizobia and the four host-plant genotypes tested does not influence local population structure, but evidence of founder effect was present. Significant linkage disequilibrium was observed and is most likely due to the clonal reproduction of R. l. bv. trifolii.
Effects of methylmercury in vitro on methionine synthase activity in various rat tissues

Methionine synthase (EC2.1.1.13) is a vitamin B 12 -dependent enzyme that catalyzes the methylation of homocysteine to produce methionine. The functional significance of this enzyme is reflected in the consequences of vitamin B 12 -deficiency or specific inhibition of methionine synthase by nitrous oxide. A mercury compound was chosen as the test toxicant because methionine synthase is a sulfhydryl enzyme, and mercurials are known to bind avidly to sulfhydryl groups which accounts for most of their toxicities
Second‐order boundary element method calculations of hydrodynamic interactions between particles in close proximity

SUMMARY A second-order boundary element technique was developed to simulate the 3D hydrodynamic interactions between multiple particles of arbitrary shape. This paper reports the results of an extensive validation procedure aimed at demonstrating the convergence characteristics of the technique, especially in cases where the particles are in close proximity. The quadratic elements are superior to the lower-order elements in terms of accuracy, computer storage and CPU time required, thus resulting in a significant improvement in the overall cQmputationa1 efficiency. Superparametric discretization improves the accuracy over isoparametric discretization but lowers the convergence rate of the method. When the interparticle gap becomes very small (less than 1% of the particle radius), the numerical solution diverges owing to inaccurate determination of the element contributions in the gap region. An adaptive subdomain integration scheme was developed that dramatically improved the integration accuracy and provided convergent solutions for problems of very small gaps down to 0.01% of the particle diameter.
Cell surface antigen and molecular targeting in the treatment of hematologic malignancies.

Conventional cytotoxic therapy of hematologic malignancies is often associated with significant morbidity. This morbidity is often due to the lack of specificity for hematopoietic cells. Therefore, the concept of targeted therapy for patients with hematologic malignancies has received attention for many years. The goal of monoclonal antibody therapy is to target specific cell surface antigens on malignant hematopoietic cells, while sparing normal cells and tissues. Currently, monoclonal antibodies are being evaluated for their cytotoxic effects as well as their ability to deliver toxic agents or radiation. Rituximab, a chimeric anti-CD20 antibody, has shown response rates of approximately 50% with minimal toxicity in patients with refractory indolent lymphoma. Campath-1H (anti-CD52) has shown encouraging results in patients previously treated for chronic lymphocytic leukemia, with response rates up to 33%, although with significant toxicity. Anti-CD33 antibodies are being used to deliver cytotoxic agents, such as calicheamicin to patients with acute myeloid leukemia with response rates up to 30%. In addition, anti-CD33 and anti-CD45 antibodies have been used to deliver radiation directly to leukemic cells. 131I-labeled anti-CD45 antibodies are being studied in combination with conventional preparative regimens in patients receiving bone marrow transplantation. Lastly, the therapeutic agent STI571 (signal transduction inhibitor 571) has demonstrated the capability of targeting specific molecular abnormalities seen in hematologic malignancies. STI571 targets the tyrosine kinase activity of the bcr-abl fusion protein seen in chronic myeloid leukemia. STI571 has induced complete hematologic responses in up to 98% of patients evaluated in clinical trials.
Risk factors for surgery in pediatric intussusception in the era of pneumatic reduction

Abstract Introduction Surgical treatment is still necessary for intussusception management in a subgroup of patients, despite advances in enema reduction techniques. Early identification of these patients should improve outcomes. Methods The medical records of patients treated for intussusception at our institution from 2006 to 2011 were reviewed. Univariate and multivariate analyses, including stepwise logistic regression, were performed. Results Overall, 379 patients were treated for intussusception, and 101 (26%) patients required operative management, with 34 undergoing intestinal resection. The post-operative complication rate was 8%. On multivariate analysis, failure of initial reduction (OR 9.9,p=0.001 95% CI, 4.6–21.2), a lead point (OR 18.5,p=0.001 95% CI, 6.6–51.8) or free/interloop fluid (OR 3.3,p=0.001 95% CI, 1.6–6.7) or bowel wall thickening on ultrasound (OR 3.3,p=0.001 95% CI, 1.1–10.1), age 2days (OR 2.9,p=0.003, 95% CI, 1.4–5.9) were significantly associated with a requirement for surgery. Similarly, a lead point (OR 14.5, p=0.005 95% CI, 2.3–90.9) or free/interloop fluid on ultrasound (OR 19.8, p=0.001 95% CI, 3.4–117) and fever (OR 7.2, p=0.023 95% CI, 1.1–46) were significantly associated with the need for intestinal resection. Conclusion Abdominal symptoms>2days, age
Natural Streams and the Legacy of Water-Powered Mills

Gravel-bedded streams are thought to have a characteristic meandering form bordered by a self-formed, fine-grained floodplain. This ideal guides a multibillion-dollar stream restoration industry. We have mapped and dated many of the deposits along mid-Atlantic streams that formed the basis for this widely accepted model. These data, as well as historical maps and records, show instead that before European settlement, the streams were small anabranching channels within extensive vegetated wetlands that accumulated little sediment but stored substantial organic carbon. Subsequently, 1 to 5 meters of slackwater sedimentation, behind tens of thousands of 17th- to 19th-century milldams, buried the presettlement wetlands with fine sediment. These findings show that most floodplains along mid-Atlantic streams are actually fill terraces, and historically incised channels are not natural archetypes for meandering streams.
Some splitting results in the K-theory of rings, II

for all n 3 0. The main cases in which the conjecture is known to be valid are the equicharacteristic case ([7], based on [2]), and the case in which k is finite (or, more generally, algebraic over a finite field) [2, lo]. In a related vein, Gillet has recently proved that the conjecture is valid for K-theory with coefficients in Z/m, so long as m 1 char k [3]. In [S] we showed that the sequence above is actually split exact whenever R contains a field L such that k is a finite separable extension of L, or whenever R is Henselian and k is finite. The main result of this note is that the Henselian hypothesis in the latter case is unnecessary:
Native American suicide in New Mexico, 1957-1979: a comparative study.

This descriptive and epidemiological study examines completed suicides among the Apache, Navajo and Pueblo Indians of New Mexico from 1957 through 1979. Death certificates constitute the primary source of data. A number of demographic and situational variables are examined for the cultural groups and similarities and differences are noted. Significant findings include a high male to female ratio ranging from 7.4:1 to 10.4:1; an age range of 10-39 for 75.4%-93.4% of the completed suicides; and a high percentage of both males and females using extremely lethal methods, i.e., firearms and hanging, to commit suicide. Suicide rates for the Apache and Pueblo groups have been rising since the mid-1960s, while Navajo rates have been rising since the early 1970s. The Apache had the highest suicide rate, followed by the Pueblo and Navajo, for the period 1957-1979. The age-adjusted rates range from 1.7 to 4.9 times the U.S. rate in recent years. Age-specific trends show an increase in youthful suicide rates similar ...
A lawyer looks at the "medical malpractice crisis".

The medical profession, hospitals, and other health-care providers have borne a disproportionate share of the brunt of a combination of inadequacies, under late-twentieth-century conditions, in thi...
Cardiovascular health in Europe: a global problem.

In the last 25 years, the world has become smaller for the cardiovascular physician in the sense that scientists and medical specialists have been able to communicate in a manner that was previously unknown. There are 2 key reasons. The first is the airplane, which has allowed physicians from all
Homogeneous nucleation ahead of the solid—liquid interface during rapid solidification of binary alloys

Abstract In recent rapid solidification experiments on Al—5%Be alloys, a Liquid Phase Nucleation (LPN) model was developed to explain the formation of periodic arrays of randomly-oriented Be-rich particles in an Al-rich matrix. In the LPN model, Be droplets were assumed to nucleate in the liquid ahead of the solid—liquid interface, but no justification for this was given. Here we present a model which considers the geometric constraints (imposed by proximity to the interface) on the number of solute atoms available to form a nucleus. Calculations based on this model predict that nucleation of second-phase particles can be most likely a short distance ahead of the interface in immiscible binary systems such as AlBe. As part of the nucleation calculations, a semi-empirical method of calculating solid—liquid surface tensions in binary systems was developed, and is presented in the Appendix.
Ankle-brachial index as a predictor of the extent of coronary atherosclerosis and cardiovascular events in patients with coronary artery disease

Resting ankle-brachial pressure index (ABI) is a noninvasive method to assess the patency of the lower extremity arterial system. This study aimed to examine the relation between ABI and the extent of coronary atherosclerosis, the extracoronary atherosclerosis lesions, and the prognosis of patients referred for elective coronary angiography. One hundred sixty-five consecutive patients underwent coronary angiography, ultrasound imaging for intima-media thickness measurement of carotid and femoral arteries and ABI evaluation; subjects were followed up for 14.5 +/- 2.4 months. With regard to vascular risk factors, only smoking (p = 0.025) and diabetes (p = 0.01) were related to ABI in the multiple regression analysis. ABI was independently and inversely related to carotid bifurcation (p = 0.0002) and common femoral artery intima-media thickness (p = 0.018). ABI was related to the extent of coronary artery disease as measured by number of coronary arteries diseased (analysis of variance, p = 0.04) and Gensini angiographic score (p = 0.01). In the follow-up study ABI 0.90 and 73% for ABI < 0.90 (p = 0.02). In logistic regression analysis, ABI < 0.90 was an independent predictor for cardiovascular events after adjustment for age, low-density lipoprotein cholesterol, carotid and femoral intima-media thickness, and Gensini score. Further adjustment for the confounding effect of insulin weakened the relation between ABI and cardiovascular events (p = 0.1). In conclusion, ABI is a simple index related to the extent of atherosclerosis in coronary and noncoronary arterial beds, reflecting generalized atherosclerosis. ABI could be useful in assessing the risk for cardiovascular events in patients with coronary artery disease.
Wave diffraction-induced crack/cohesive strip growth based on rudimentary non-linear models

The reaction of a Mode I 2D semi-infinite crack to the diffraction of a plane tension wave in an unbounded solid is treated. A vanishingly thin cohesive zone, or strip, represents rudimentary crack edge yield, and two generic response laws that incorporate rudimentary non-linear effects are studied. Simultaneous crack/zone growth at constant rates is treated, with pure zone growth recovered as a limit case. Both models involve multiple solution sets that can be obtained analytically and studied. Attention focuses on those associated with uniform strip fields. Results based on parameters for 2024-T4 aluminum and 4130-HT steel suggest that the two models involve tension loads critical for crack/zone growth lower than standard model predictions, especially for high growth rates. The results also suggest that dynamic crack/zone growth may be more sensitive to multiaxiality near the crack edge, and proceed at lower loads. All of these results are general in the sense that they are obtained without specifying a complete set of growth criteria.
Reduced incidence and mortality from colorectal cancer with flexible-sigmoidoscopy screening: a meta-analysis.

Reduced incidence and mortality from colorectal cancer with flexible-sigmoidoscopy screening: A meta-analysis
Charge-dependent dissociation of insulin cations via ion/ion electron transfer

Abstract The dissociation reactions of various charge states of insulin cations obtained directly from nano-electrospray were investigated as a result of ion/ion electron transfer from azobenzene anions. Data were collected with and without simultaneous ion trap collisional excitation of the first generation charge-reduced product during the ion/ion reaction period. Neither separation of the two constituent chains nor cleavages within the loop defined by the disulfide bridges were observed under normal electron transfer dissociation (ETD) conditions for any of the charge states studied. However, substantial sequence coverage (exocyclic region: 82.6%; entire protein: 38.8%) outside the ring structure was obtained for insulin +6, while only limited coverage (exocyclic: 43.5%; entire protein: 20.4%) was observed for insulin +5 and no dissociation, aside from low abundance side-chain losses, was noted for insulin +4 and +3 in the normal ETD spectra. When the first generation charge-reduced precursor ions were subjected to collisional activation during the ion/ion reaction period, higher sequence coverages were obtained for both insulin +5 (entire protein: 34.7%) and +4 (entire protein: 20.4%) with backbone cleavages occurring within the loop defined by the disulfide bonds. Dissociation of insulin +3 was not significantly improved by the additional activation. Separation of the two constituent chains resulting from cleavages of both of the two disulfide bridges that link the chains was observed for insulin +6, +5, and +4 when the charge-reduced species were activated. The dissociation of disulfide linkages in this study suggests that as the charge state decreases, disulfide bond cleavages dominate over N–Cα bond cleavages in the electron transfer dissociation process.
Targeting OX40 and OX40L for the treatment of autoimmunity and cancer.

The optimal activation of naive T cells requires TCR-mediated recognition of cognate peptide-MHC complexes on antigen presenting cells in the presence of costimulatory signals. Although signals provided via CD28-B7 interactions are important for enhancing the initial T-cell response, other costimulatory signals are required for sustaining the response and promoting both T-cell differentiation and survival. In particular, engagement of OX40 (CD134) by its natural ligand OX40L (CD134L) or OX40 agonists has been shown to provide key signals that can augment CD4 and CD8 T-cell responses. Importantly, numerous studies have highlighted the ability of OX40-specific agonists or antagonists to enhance antitumor immunity or ameliorate autoimmune disease, respectively. On the basis of these studies, the development of OX40- and OX40L-specific reagents has been pursued for clinical use. Given the emerging role of OX40 and OX40L as novel therapeutic targets, this review will focus on the cellular and molecular mechanisms of OX40-mediated T-cell costimulation with a special emphasis on the role of OX40-OX40L interactions in the etiology and treatment of autoimmunity and cancer.
A comparison of cognitive structure in schizophrenia patients and healthy controls using confirmatory factor analysis

There is evidence that cognitive task performance breaks down into the same broad domains in schizophrenia as in healthy populations. However, this does not mean that the domains are independent of one another or that the interrelationships among domains are the same between groups. We used confirmatory factor analysis (CFA) to compare the latent structure of a broad neuropsychological battery in schizophrenia patients (n = 148) and healthy controls (n = 157). Main analyses examined the fit of a hierarchical six-factor model, in which associations among the factors were assumed to reflect their strong shared relationship to a general cognitive ability factor. The model incorporated the factors of verbal comprehension, perceptual organization, verbal memory, spatial memory, processing speed, and executive/working memory. The hierarchical model provided a good overall fit to data from both groups. However multiple groups CFA revealed significant differences in factor loadings between groups, reflecting a more generalized latent structure of cognitive ability in schizophrenia. This was also evident in higher bivariate correlations among cognitive domain composite scores calculated from the observed test data. Cognitive ability, as reflected in test performance, appears to be more unitary in schizophrenia than in healthy subjects. This finding may have measurement and treatment implications.
1499 ROLE OF O2-HEMOGLOBIN AFFINITY ON THE RESPONSE TO HYPOXIA OF CEREBRAL BLOOD FLOW IN THE FETAL SHEEP

The increase in cerebral blood flow (CBF) with hypoxia is greater in fetal than adult sheep. Baseline CBF and oxygen delivery (OD=CBF × arterial O2 content) are also higher in the fetal sheep despite a rate of cerebral O2 consumption (CMRO2) equal to that in the adult. Previous work showed that this relative overperfusion of the fetal brain is in part due to the left shifted position of the O2-hemoglobin dissociation curve (ODC) in the fetus. 6 unanesthetized fetal sheep were studied to determine if the greater response of CBF to hypoxia in the fetus is also dependent upon the position of the ODC. Measurements of blood gases, CBF (microsphere technique), CMRO2, OD, and the reciprocal of the arteriovenous (brachiocephalic a. - sagittal sinus) difference in O2 content (1/CaO2-CvO2) were made at 3 levels of CaO2 pre and postexchange transfusion (ET) with adult blood. 1/CaO2-CvO2=CBF/CMRO2 measures changes in CBF if CMRO2 remains stable and is less subject to error than micro-sphere CBF measurements. P50 increased from 16.6 ± 0.5 - 31.7 ± 1.9 Torr (±SEM) and OD decreased 13.12 ± 1.56 - 6.63 ± 0.34 ml·100g−1·min−1 with ET (p < .05). During hypoxia, CMRO2 was unchanged both pre and post ET. The response of 1/CaO2-CvO2 to hypoxia was steeper pre ET (p <.05). These data support the role of the position of the ODC in the regulation of CBF during hypoxia and are consistent with a tissue O2 dependent mechanism of CBF control.
An Assessment of Studies on Homogeneous Diffusional Nucleation Kinetics in Binary Metallic Alloys

A critical review is presented of all studies on homogeneous nucleation kinetics in crystalline binary metallic alloys located in the literature. Emphasis was first placed upon examining the data on the number of precipitates per unit volume of matrix phase,N v , recorded as a function of isothermal reaction or aging time. With the exception of the results of a few studies on Cu-rich Cu-Co alloys, all of these data were extensively “contaminated” by significant overlapping of the diffusion fields of adjacent precipitates and especially by concurrent coarsening. The use of the “nucleation window” concept was advocated as a means of finding a range of alloy compositions and reaction temperatures in a particular alloy system within which sufficient data onN v vs time can be collected to evaluate the steady-state nucleation rate,J s * without significant intervention by either disturbing effect. Transmission electron microscopy (TEM) was identified as a particularly valuable experimental tool for measuringN v . However, smallangle neutron scattering (SANS) is also proving useful for this purpose, and the combination of SANS with FIM-AP (field ion microscope-atom probe) has uncovered information of crucial importance to understanding the transformation sequence in Cu-Co alloys. Wagner and co-workers[52,62,63,64-78-79] have demonstrated the presence of precursor Co segregations large in extent but small in amplitude, of which the most successful lead to the formation of identifiable precipitates (within which segregation is very much larger in amplitude but considerably smaller in extent). The Wagneret al. work suggests that the supersaturations at which they formed were insufficient to permit the fluctuations which did not eventually fulfill exactly the specifications for critical nuclei to evolve into precipitates. While classical, the Cahn-Hilliard continuum nonclassical [su2] and Cook-deFontaine discrete lattice point nonclassical nucleation theories[25,26,27] yield nearly identical results in the temperature-Co concentration range experimentally studied, theJ* s values thus calculated are a few orders of magnitude smaller than the experimentally measured rates when the concentration of vacancies present at the reaction temperature is (reasonably) assumed operative. On the basis of theoretical and computer simulation studies by Binderet al. [84,87,89,90] and Kleinet al.,[91–94] the observed precursor concentration fluctuations are indicative of relatively long-range interactions among adjacent atoms in Cu-Co alloys, whereas the solution thermodynamics so far applied to this system is based upon the use of short interaction distances. This is suggested to be the principal source of the discrepancy between measured and calculated nucleation kinetics in Cu-Co alloys. Suggestions are offered for future research intended to clarify some of the complexities which have recently become apparent in studies of homogeneous nucleation kinetics in binary metallic alloys.
Mechanical properties of a polyurethane elastomer in the rubber-to-glass transition zone

Abstract The complex shear compliance of a polyurethane elastomer has been measured in the transition region from rubbery to glasslike properties with a Fitzgerald transducer. Values for the real and imaginary components of the complex shear compliance J ′ and J ″ are reported over a frequency range of 45 to 6000 cycles/sec, and a temperature range of −16 to 39°C. Composite curves of J ′ and J ″ reduced to a standard temperature were obtained by the method of reduced variables. The temperature shift factors followed the WLF equation. The data do not extend to high enough reduced frequencies to approach the glassy compliance, but at low frequencies the dynamic compliance is essentially equal to the equilibrium rubbery value. The loss tangent J″ J′ passes through an extremely broad maximum with increasing frequency. The shape of the retardation distribution function resembles that of polyisobutylene; however, the value of the ratio of the maximum in the retardation distribution function to the equilibrium compliance is not the same for the two polymers. The value for the polyurethane agrees instead with that previously found for cellulose tributyrate and polyvinyl chloride gels (which are crosslinked by crystallization). For several decades at the long time end of the transition zone the relaxation distribution function has the slope of −1 2 prescribed by the Rouse theory, as does a 20.4% cellulose tributyrate gel. At shorter times the experimental curve rises more steeply than predicted by theory, just as do the corresponding curves for vinyl polymers. However, the total deviation from the linear theoretical curve is small and the overall shape of the relaxation distribution function for the polyurethane more nearly resembles that found for disubstituted than for monosubstituted vinyls.
Integrin-dependent role of human T cell matrix metalloproteinase activity in chemotaxis through a model basement membrane.

Human T lymphoblastoma cells of the CD4+ 8+ Tsup-1 line, that express alpha4 and alpha5 but not alpha6 integrins of the beta1 family, and CD4+ human blood T cells bind vasoactive intestinal peptide (VIP) with high affinity, leading to increased adherence, secretion of matrix metalloproteinases (MMPs), and chemotaxis. VIP-enhanced adherence of T cells to fibronectin was inhibited significantly by neutralizing monoclonal antibodies to beta1 > alpha4 >> alpha5, but not to alpha6. Antibodies to beta1 and alpha4 suppressed to a similarly significant extent VIP stimulation of both MMP-dependent T cell chemotaxis through fibronectin-enriched Matrigel and T cell degradation of 3H-type IV collagen in the Matrigel, without affecting VIP-evoked secretion of MMP by suspensions of T cells. The lesser inhibition of VIP-enhanced adherence of T cells to fibronectin by anti-alpha5 antibody, than antibodies to beta1 or alpha4 chains, was associated with lesser or no suppression of MMP-dependent T cell chemotaxis through Matrigel and T cell degradation of type IV collagen in the Matrigel in response to VIP. Specific beta1 integrins thus mediate interactions of stimulated T cells with basement membranes, including adherence, localized digestion by MMPs, and chemotactic passage, that promote entry of T cells into extravascular tissues. © 1996 Wiley-Liss, Inc.
An Experimental Study of the Effects of Surface Lay Orientations on Initial Surface Damage in Point Contacts

An experimental investigation to determine the effects of surface roughness lay direction relative to the direction of motion on initial surface damage was conducted using a four-ball machine under both simple sliding and pure rolling point contact conditions. Surface topographies ranging from 0.11 μm (4.45 μm) to 0.73 μm (28.61 μm.) RMS roughness and 31.5 μm (1239 μin.) to 59.6 μm (2345 μin.) in wavelength were utilized in the experimental program. A lithium complex grease was used as the lubricant for all tests. The experimental results indicate that surfaces with transverse lay orientations cause more initial surface damage than surfaces with longitudinal lay orientations for relatively low ratios of film thickness-to-composite surface roughness, and low ratios of surf ace wavelength-to-contact radius. Presented at the 47th Annual Meeting in Philadelphia, Pennsylvania May 4–7, 1992
First report of charcoal rot of sunflower in Minnesota, USA.

Charcoal rot was first observed on sunflower in North and South Dakota in 1998, and was widespread on soybeans recently in Iowa, suggesting that Macrophomina may becoming more common in cooler grow...
Relationship of Boron Nutrition to Radiosensitivity of Sunflower Plants.

Seven-day-old Mammoth Russian sunflower seedlings were grown in nutrient solutions with or without boron, for 2 to 5 days, after which they were x irradiated and again supplied with boron. Withholding boron for short intervals prior to x irradiation with doses that normally produce pronounced radiation symptoms, had a marked alleviating effect on the development of radiation injury. The absence of boron resulted in retardation of some phase of cellular activity and rendered the plants more radioresistant. This normally radiosensitive phase of cellular activity which may be rendered relatively radioresistant by withholding boron is, then, berondependent. An attempt was made to identify this growth phase by irradiating a series of germinating seedlings at different growth stages. lt appeared to be the phase of cellular maturation rather than cell division, suggesting that boron is required for some process or processes concerned with cellular maturation or differentiation. The apparent effect of boron on sugar translocation appears to be related to the effect of boron on cellular activity rather than to a direct enhancement of diffusion through membranes through formation of a sugar-borate complex. (auth)
Social Security Outcomes by Racial and Education Groups

This article evaluates the Social Security outcomes for different racial and education groups. Outcomes differ across groups due to the interactions between group-specific mortality risks and lifetime earnings, the benefit formula, and the benefit package, which includes life insurance, spousal benefits, and retirement pensions. Based on either the rate of return or present value, individuals with less education fare better than those with higher educations. This holds even before accounting for preretirement survivors' benefits, which, when accounted for, reinforce this finding. Single whites do considerably better than single blacks when outcomes are compared by internal rates of return. Accounting for survivors' benefits reduces regressivity, but blacks continue to fare worse than whites. In contrast, based on present values, whites generally do worse than their respective counterparts. Social Security is primarily an intergenerational transfer system providing payments to retired workers and their families financed by payroll taxes on current workers. The Old-Age and Survivors Insurance (OASI) program also provides life insurance through survivors benefits. Because longer lives are positively related to income, the retirement pension favors workers with higher lifetime incomes, other things equal. Conversely, survivors' insurance is more likely to be awarded within groups with higher mortality rates at younger ages, which happens to be those with lower incomes. Further, the benefit formula replaces a higher percentage of the income of workers with lower lifetime earnings, while spousal retirement benefits favor couples in which only one spouse works. As a result, any particular group's outcome depends on their lifetime earnings, their group-specific longevity, the tax rates they face, and the Social Security benefit formula. There have been quite a few studies devoted to calculating the internal rate of return and net present value of Social Security.' Some consensus has been reached by those studies: early generations do better than later generations, women do better than men, and married couples with a single earner do better than singles or working couples. These results are not surprising given that a pay-as-you-go system usually generates a higher return in its start-up phase than in the mature phase, that women live longer than men, and that nonworking spouses receive benefits without making tax payments. However, to date, a consensus has not been reached on some of the more interesting but less obvious issues such as how different income classes or different races fare in the system. This article
Ada exception handling: an axiomatic approach

A method of documenting exception propagation and handling in Ada programs is proposed. Exception propagation declarations are introduced as a new component of Ada specifications, permitting documentation of those exceptions that can be propagated by a subprogram. Exception handlers are documented by entry assertions. Axioms and proof rules for Ada exceptions given. These rules are simple extensions of previous rules for Pascal and define an axiomatic semantics of Ada exceptions. As a result, Ada programs specified according to the method can be analyzed by formal proof techniques for consistency with their specifications, even if they employ exception propagation and handling to achieve required results (i.e., nonerror situations). Example verifications are given.
Detection of remote myocardial infarction with quantitative real-time ultrasonic characterization.

We have previously shown that the intrinsic properties of myocardium can be characterized quantitatively by the assessment of ultrasonic integrated backscatter. In this study we utilized a novel, real-time, two-dimensional system capable of quantitative integrated backscatter imaging to determine whether zones of remote myocardial infarction in dogs could be delineated definitively by ultrasonic tissue characterization. Detection of such zones in patients is needed as a basis for management decisions related to thrombolysis, angioplasty, and coronary surgery. Integrated backscatter was measured through the closed chest from 25 myocardial sites. Zones of infarction exhibited time-averaged integrated backscatter values approximately 10 dB (9.5 ± 0.5 dB, standard error of the mean) greater than those in normal regions ( p p
Intermediaries and Cybermediaries: Sarkar, Butler and Steinfield

The advent of nearly ubiquitous information infrastructures has led many to predict that one effect of electronic markets will be the bypassing of intermediaries in electronic markets. The ability of electronic networks to reduce transaction costs is the theoretical cause of this supposed trend. We suggest that, on the contrary, not only is it likely that widely available information infrastructures will reinforce the position of traditional intermediaries, but that networks will also promote the growth of a new generation of intermediaries. These new players, which we term “Cybermediaries,” are organizations that perform the mediating tasks in the world of electronic commerce. We illustrate that the case for the elimination of intermediaries in the move to create direct producer-consumer links is based on questionable assumptions. We then examine functions of intermediaries that are not easily absorbed by producers. We describe some of the new forms of cybermediaries, noting the new needs that electronic commerce imposes on producers and consumers. We note that using a rational, economic logic rooted in transaction cost theory, it is equally plausible to conclude that more, rather than fewer intermediaries will be involved in electronic markets. Finally, we briefly highlight several social and institutional factors that also may mitigate against the elimination of intermediaries. This broader perspective of the role of intermediaries in the exchange process calls for incorporating consumer-centric and institutional perspectives into the discussion of the evolution of electronic market structures.
“I Don't Make the Soups Anymore”: Pre- to Post-Migration Dietary and Lifestyle Changes Among Latinos Living in West-Central Florida

Eighteen Latino adults living in the U.S. for less than 2.5 years were surveyed and interviewed about their pre- and post-migration diets and lifestyles. While this mostly female sample reported that their primary language was Spanish, many had some limited skills in written and spoken English. Two thirds were from Colombia, married, and had between 1 and 4 children, and more than half had post-secondary education. Percent change in diet, food habits, and activities associated with lifestyle, regardless of the direction, ranged from a low of 27.8% of the sample for alcohol consumption to a high of 100% for both physical activity and sedentary behavior. In most cases, post-immigration food types and behaviors represented unhealthy changes, including weight gain, a lack of physical activity, and a corresponding increase in television viewing time and in the consumption of fast food, processed food, soda, and, to a lesser extent, artificial juices. Ten participants were interviewed about daily life in their native countries (pre-migration) and since coming to the U.S. (post-migration). Six primary themes emerged with regard to post-migration lifestyle changes: pace of life, family interaction, social integration, socioeconomic status, physical security, and control over children's eating patterns. All of these themes were related to decision-making regarding food choices and food habits, and in many cases such decisions were detrimental to health.
Lume di Lume: A Theory of Light and Its Effects

Abstract This article is an investigation of an enigmatic drawing from an Italian Renaissance treatise and its companion text. Its aim is to understand the drawing by situating it amid contemporary optical theory and to show how the text contributes a new appreciation for light in architecture in its time. Finally, it attempts to provide an interpretation of the drawing and text useful today — namely, the idea that architecture becomes visible not simply by its existence in light but in the creation of a penumbral zone between darkness and light.
The strength and toughness of cement reinforced with bone-shaped steel wires

In this study, we have experimentally evaluated the effectiveness of bone-shaped short (BSS) steel wire reinforcement in improving the mechanical properties of cement. Results from four-point bending tests revealed that BSS-steel-wire-reinforced cement is substantially stronger, tougher, and more crack resistant than conventional straight short (CSS) steel-wire-reinforced cement and unreinforced cement. The BSS steel wires provided effective crack bridging by a combination of their ductility and the mechanical interlocking between their enlarged spherical ends and the cement matrix. In the BSS-wire-reinforced cement specimens, multiple cracks formed along the length of the specimen before final failure, whereas in the CSS-wire-reinforced cement and unreinforced cement specimens, a single central crack initiated and propagated across the specimen. Some BSS wires bridged the main crack and were eventually plastically deformed to failure. Secondary matrix cracks also radiated away from the main fracture surfaces, providing significant contributions to the toughness of the composites. In contrast, the bridging CSS wires were easily pulled out of the matrix without much deformation in the wire itself and surrounding cement. Therefore, they were not nearly as effective in bridging cracks and improving toughness as the BSS wires.
Revisiting strategic decision success

The purpose of this article is to extend and reinforce previous research intended to demonstrate that a process model of decision making is conducive to strategic decision success. Using a strategic decision matrix with a two‐dimensional focus, 16 high‐visibility strategic decisions from different corporations in the 1990s are evaluated and classified to support the hypothesis that a formal decision‐making process is conducive to successful strategic decision outcomes. The results of this evaluation clearly indicate that, in the absence of a managerial decision‐making process, successful outcomes are unlikely to materialize. Conversely, although a process‐oriented approach to strategic choice affords no guarantee of a successful outcome, the likelihood of this occurrence tends to increase with this approach. This revisiting of strategic decision success confirms earlier research in this critical area. Hopefully, it will elicit subsequent research of a similar nature.
How well can the IEEE 802.11 wireless LAN support quality of service

This paper studies an important problem in the IEEE 802.11 distributed coordination function (DCF)-based wireless local area network (WLAN): how well can the network support quality of service (QoS). Specifically, this paper analyzes the network's performance in terms of maximum protocol capacity or throughput, delay, and packet loss rate. Although the performance of the 802.11 protocol, such as throughput or delay, has been extensively studied in the saturated case, it is demonstrated that maximum protocol capacity can only be achieved in the nonsaturated case and is almost independent of the number of active nodes. By analyzing packet delay, consisting of medium access control (MAC) service time and waiting time, accurate estimates were derived for delay and delay variation when the throughput increases from zero to the maximum value. Packet loss rate is also given for the nonsaturated case. Furthermore, it is shown that the channel busyness ratio provides precise and robust information about the current network status, which can be utilized to facilitate QoS provisioning. The authors have conducted a comprehensive simulation study to verify their analytical results and to tune the 802.11 to work at the optimal point with maximum throughput and low delay and packet loss rate. The simulation results show that by controlling the total traffic rate, the original 802.11 protocol can support strict QoS requirements, such as those required by voice over Internet protocol (VoIP) or streaming video, and at the same time achieve high channel utilization.
Apolipoprotein A-I/B Ratios May Be Useful in Coronary Heart Disease Risk Assessment

Henry O. Ogedegbe, PhD, BB(ASCP)SC Department of Environmental Health, Molecular and Clinical Sciences, Florida Gulf Coast University, Fort Myers, FL anti-factor Xa of 0.20 U/mL with a range of 0.01 to 1.00 U/mL. The average bias for these 54 paired samples was 0.01 U/mL, indicating no meaningful effect of the pneumatic tube delivery on anti-factor Xa measurements. As shown in T2, the 37 rapid, higher speed centrifugation comparison samples had a median anti-factor Xa of 0.17 U/mL with a range of 0.01 to 0.89 U/mL. The average bias for these 37 paired samples was 0.00 U/mL, indicating no meaningful effect of rapid, higher speed centrifugation on anti-factor Xa measurements. Discussion The anti-factor Xa assay is sensitive to the release of the heparin neutralizing substance platelet factor 4 from normal blood platelets.2 Although several previous studies of pneumatic tube delivery and rapid, higher-speed centrifugation did not detect effects on platelet counts, coagulation factor levels, prothrombin times, activated partial thromboplastin times, or fibrinogen concentrations,6,7 we found no reports studying the anti-factor Xa assay. Neither pneumatic tube delivery nor rapid, higher-speed centrifugation caused a detectable effect on the antifactor Xa assay in this study. These technologies speed coagulation laboratory work and appear to be acceptable for chromogenic anti-factor Xa assay monitoring of heparin therapy.
Reduced electrocortical response to threatening faces in major depressive disorder.

Background: There is growing support for the emotion context insensitivity hypothesis, which states that major depressive disorder (MDD) is associated with a deficit in emotional reactivity. Under this hypothesis, depressed individuals exhibit reduced behavioral and physiological responses to both appetitive and aversive stimuli. We sought to examine this possibility using the late positive potential, a neural response sensitive to aversive and threatening stimuli. Methods: Forty-seven individuals participated in the study, 22 of whom met criteria for current MDD and 25 with no history of depression or other Axis I disorders. All individuals passively viewed emotional faces while event-related potentials were recorded. Results: The vertex positive potential was significantly increased in response to fearful and angry faces across the entire sample. The late positive potential was also increased in response to threatening faces, but only among never-depressed individuals. In the MDD group, this electrocortical response to emotional faces was absent. Conclusions: This study provides neural evidence in support of the view that MDD is associated with blunted emotional reactivity to negative stimuli, which until now has been examined primarily with measures of behavior, self-report, and peripheral physiology. These results are also consistent with two prior studies showing reduced amygdala activation in response to fearful faces among depressed individuals. It remains to be determined whether abnormal activity in response to emotional stimuli is associated with trait risk for MDD or results from MDD. Depression and Anxiety 27:813–820, 2010. r 2010 Wiley-Liss, Inc.
A Configuration Control Mechanism Based on Concurrency Level for a Reconfigurable Consistency Algorithm

A Reconfigurable Consistency Algorithm (RCA) is an algorithm that guarantees the consistency in Distributed Shared Memory (DSM) Systems. In a RCA, there is a Configuration Control Layer (CCL) that is responsible for selecting the most suitable RCA configuration (behavior) for a specific workload and DSM system. In previous works, we defined an upper bound performance for RCA based on an ideal CCL, which knows apriori the best configuration for each situation. This ideal CCL is based on a set of workloads characteristics that, in most situations, are difficult to extract from the applications (percentage of shared write and read operations and sharing patterns). In this paper we propose, develop and present a heuristical configuration control mechanism for the CCL implementation. This mechanism is based on an easily obtained applications parameter, the concurrency level. Our results show that this configuration control mechanism improves the RCA performance in 15%, on average, compared to other traditional consistency algorithms. Furthermore, the CCL with this mechanism is independent from the workload and DSM system specific characteristics, like sharing patterns and percentage of writes and reads.