cssi/SciSciGPT-SciSciNet huggingface dataset:
Hyperleukocytic Leukemias: Rheological, Clinical, and Therapeutic Considerations

A small proportion of patients with acute or chronic leukemia has an extraordinarily high blood leukocyte count. These high counts can result in a very high fractional volume of leukocytes (leukocrit), which is also a function of the mean leukocyte volume in different types of leukemia. Despite a high fractional volume of leukocytes, bulk viscosity of blood is usually not increased because a decrement in the fractional volume of erythrocytes accompanies the increase in leukocytes. Nevertheless, the excessive numbers of leukocytes present two major problems: first, they can seriously affect flow in the circulation of the lung, brain, and less often, other organs by obstructing microchannels or by forming aggregates and white thrombi in small veins. Moreover, leukemic blasts may compete for oxygen in the microcirculation and they may be invasive, damaging vessel walls. Second, their rapid destruction in response to cytotoxic drugs causes metabolic disturbances, especially uric acid accumulation, which can lead to obstructive uropathy.
Signal and Noise

Signal and Noise (Azim Celik and Weili Lin, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina). This unit discusses the basic signal detection technique in magnetic resonance imaging based on quadrature (i.e., measured in two orthogonal channels) technique. The detected signal is demodulated with respect to the Larmor frequency and digitized. The measured MR signal also includes noise. The noise in MR generally derives from the random fluctuations in the receive coil electronics and from the sample. Even though there are other sources of signal fluctuations such as digitization noise and pseudo-random ghosting due to moving spins, these sources are minimized in an ideal experiment. The effect of these noises in MRI image reconstruction is explained in this unit.
The Vibrio cholerae Pst2 Phosphate Transport System Is Upregulated in Biofilms and Contributes to Biofilm-Induced Hyperinfectivity

Vibrio cholerae is the causative agent of the deadly diarrheal disease cholera. As part of its life cycle, V. cholerae persists in marine environments, where it forms surface-attached communities commonly described as biofilms. Evidence indicates that these biofilms constitute the infectious form of the pathogen during outbreaks. Previous work has shown that biofilm-derived V. cholerae cells, even when fully dispersed from the biofilm matrix, are vastly more infectious than planktonic (free-living) cells. Here, we sought to identify factors that contribute to biofilm-induced hyperinfectivity in V. cholerae, and we present evidence for one aspect of the molecular basis of this phenotype. We identified proteins upregulated during growth in biofilms and determined their contributions to the hyperinfectivity phenotype. We found that PstS2, the periplasmic component of the Pst2 phosphate uptake system, was enriched in biofilms. Another gene in the pst2 locus was transcriptionally upregulated in biofilms. Using the infant mouse model, we found that mutation of two pst2 components resulted in impaired colonization. Importantly, deletion of the Pst2 inner membrane complex caused a greater colonization defect after growth in a biofilm compared to shaking culture. Based on these data, we propose that V. cholerae cells in biofilms upregulate the Pst2 system and therefore gain an advantage upon entry into the host. Further characterization of factors contributing to biofilm-induced hyperinfectivity in V. cholerae will improve our understanding of the transmission of the bacteria from natural aquatic habitats to the human host.
A novel disruption of cortical development in p35(-/-) mice distinct from reeler.

The p35/cdk5 neuronal-specific kinase complex has been shown to play an important role in the laminar configuration of cortical neurons. Mice lacking either p35 or cdk5 exhibit a disrupted cortical lamination pattern. We showed previously that instead of the normal “inside–out” layering pattern of cortical neurons, cortical neurons are layered from “outside–in” in p35 mutant mice. To gain insight into the mechanisms that underlie these defects, we examined the organization of landmark structures formed during cortical development and the migratory behavior of p35−/− cortical neurons by using bromodeoxyuridine labeling. In the present study, we show that reelin localization in the marginal zone is normal in p35 mutant mice. Furthermore, the preplate splits into the marginal zone and subplate properly, a developmental event that fails to occur in reeler mice. Finally, the migration of the earliest born cortical plate neurons is normal in p35 mutant mice; cortical neurons subsequently generated remain underneath these neurons. These data suggest that the p35/cdk5 kinase is required for cortical plate neurons to migrate past preexisting neurons and take up superficial positions to constitute the inside–outside layering order of cortical lamination. J. Comp. Neurol. 395:510–522, 1998. © 1998 Wiley-Liss, Inc.
Developmental changes in the effects of drugs acting at NMDA or non-NMDA receptors on synaptic transmission in the chick cochlear nucleus (nuc. magnocellularis)

Abstract The developmental pharmacology of excitatory amino acid (EAA) receptors in the chick cochlear nucleus (nucleus magnocellularis, NM) was studied by means of bath application of drugs and recording of synaptically-evoked field potentials in brain slices taken from chicks aged embryonic day (E) 14 through hatching (E21). The abilities of various EAA agonists ( N- methyl- d -aspartate [NMDA], kainic acid, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [AMPA]) to suppress postsynaptic responses by depolarization block and of EAA antagonists ((3-[RS]-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid [CCP], dizocilpine [MK-801], 6-nitro-7-sulfamoyl-benzo(F)quinoxaline-2,3 dione [NBQX], 6-cyano-7-nitroquinoxaline-2,3-dione [CNQX] and 6,7-dinitroquinoxaline-2,3-dione [DNQX]) to suppress these responses directly were assessed quantitatively. The results support the existence of NMDA receptors in NM and suggest that the ability of these receptors to influence synaptically-evoked responses declines dramatically during the last week of embryonic life. The results similarly suggest that the non-NMDA receptors in NM undergo changes in density and/or function during a period of development when the cochlear nucleus is undergoing a variety of morphological and functional transformations.
No acute changes in postural control after soccer heading

Background: Soccer heading has been proposed as a potential cause of cerebral dysfunction. Objective: To examine the acute effects of two types of soccer heading on postural control. Methods: Collegiate soccer players were randomly assigned to one of four groups: control, linear heading, simulated rotational heading, or rotational heading. Each subject completed a baseline postural stability assessment on day 1. On day 2 the same assessment was completed for the control subjects. The simulated rotational heading group completed a simulated heading drill before postural stability testing. The linear and rotational heading groups performed a heading drill with 20 balls at 88.71 km/h (55 mph), before postural stability testing. Separate one between (group), three within (surface, eyes, and day), mixed model, repeated measures analyses of variance were conducted on values for total sway and mean centre of pressure. Results: The mixed model analysis of variance of results showed no significant differences (p>0.05) for the interactions of interest for either variable. Results suggest no acute changes in measures of postural control in soccer players completing either a linear or rotational soccer heading drill of 20 balls at a fixed speed. Conclusion: Non-significant interactions between surface, eyes, day, and group indicate that sensory interaction of the balance mechanism components are not be compromised by the heading drill. This research supports previous studies suggesting that there are no acute risks associated with routine soccer heading. A direct comparison between these findings and those suggesting long term chronic deficits, however, cannot be made. Other studies that report chronic cerebral deficits in soccer players may have resulted from factors other than soccer heading and warrant further examination.
Public accountability and the project-grant mechanism

Abstract The project-grant mechanism is a major determinant of research styles and the direction and degree of scientific progress. Insofar as such research increasingly serves as the source of technology, and thus of economic, social and political change, the mechanism also influences, if only indirectly, the societal condition. In its current form the mechanism permits the support of significant amounts of research to be determined on the basis of scientific merit. The result has been the substitution of scientific progress for the achievement of tangible technical ends as the measure of public accountability. Given the increased appearance of undesirable social consequences based, in part, on scientific accomplishments this substitution is now seriously questioned. It has given rise to several attempts to make academic research more responsive to public needs while attempting to preserve the essentials of academic freedom.
Therapy of X-linked adrenoleukodystrophy

Current therapies for X-linked adrenoleukodystrophy (X-ALD) include replacement therapy with adrenal steroids, which is mandatory for all patients with impaired adrenal function but does not alter neurological progression significantly; dietary therapy with “Lorenzo’s Oil,” which appears to have a preventive effect in asymptomatic boys whose brain MRI is normal; and hematopoietic stem cell transplantation in patients in the early stage of the cerebral inflammatory phenotype. Application of these interventions requires careful assessment of the patients’ phenotype, which often changes over time. Family screening provides important opportunities for disease prevention.
Sonograph mosaics of submarine slope instabilities, Mississippi River Delta

Abstract Sonograph mosaics of submarine slope instabilities have been compiled from new sonographs that were acquired from an area of the Mississippi delta-front slope in water depths of 10–50 m. The sonographs are free from scale distortions, and tonal and textural patterns indicate considerable topographic variety, including subparallel scarps, blocky areas enclosed by scarps, elongate sinuous channels, depositional lobes, and collapse depressions. These are interpreted as the results of various types of subaqueous mass movement. Adjacent scale-true survey lines have been combined, using accurate navigation, yielding the first-ever composite sonograph mosaics of submarine slope instabilities. The mosaics represent both internal feature detail and spatial associations.
Ultrastructure of experimental cocaine hepatotoxicity.

Cocaine is a potent hepatotoxin in mice. It is converted in the liver by a minor oxidative pathway to the active metabolite, norcocaine nitroxide. Previous studies have shown evidence of a lipid peroxidative mechanism of toxicity, including increased conjugated diene absorption by hepatic microsomal lipids following a single 60 mg per kg i.p. dose of cocaine in DBA/2Ha mice. To explore this mechanism further, morphologic changesin the livers of DBA/2Ha mice were examined following the same dose of cocaine. The first ultrastructural change seen was dilatation of rough endoplasmic reticulum in centrilobular hepatocytes 1 hr following cocaine injection, coincident with the previously observed onset of increased conjugated diene absorption in microsomal lipids. During the previously observed period of peak conjugated diene absorption (2 to 4 hr), ultrastructural changes in centrilobular hepatocytes progressed. These included focal mitochondrial membrane disruption followed by more extensive mitochondrial swelling and disruption with increased swelling of rough endoplasmic reticulum. Changes in size, shape and concentration of histochemically labeled, morphometrically studied peroxisomes were also seen during this interval. Injury of centrilobular hepatocytes advanced to cell death in 6 to 8 hr. The time course and nature of these morphologic findings correlate with previously observed evidence of lipid peroxidation, supporting the hypothesis that this is the mechanism of cocaine hepatoxicity.
Microwave spectrum, structure, and chemical bonding of trimethylbromosilane

Abstract The microwave spectrum of trimethylbromosilane (trimethylsilylbromide) has been investigated in the 26.5–40.0-GHz region. Spectra of several isotopic species have been observed, including the previously unreported spectrum of the 1H12C30Si81Br species, which yielded a B rotational constant of 1440.92 ± 0.02 MHz. From the experimental data it has been possible to derive the following structural parameters: SiBr = 2.235 ± 0.002 A, SiC = 1.856 ± 0.010 A, and ∠CSiBr = 107.5 ± 0.1°. The results have been compared to other relevant data and discussed in terms of prevailing chemical bonding principles.
The Columbian Timber Beetle, Corthylus columbianus (Coleoptera: Scolytidae). III. Definition of Epiphytotics1

Epiphytotics of the Columbian timber beetle, Corthylus columbianus Hopkins, and the conditions leading to them can be defined through examination of egg cradle densities for individual trees, attack densities for individual trees average attack densities for all hosts, and the percentage of hosts attacked. The most valid expression of Columbian timber beetle populations through time is the number of cradles (egg chambers) per square foot of bark surface at the ring where the attacks were initiated. On this basis, an outbreak is defined as densities greater than long-term averages. A general equilibrium position of 3.36 was established for the beetle; epiphytotics occurred in 1948–51. 1956, and 1959–61. Outbreak conditions always existed when the number of attacks per square foot on the lower 3 feet of the hole exceeded 0.7 or when 59% or more of the trees were attacked. Conditions prior to outbreaks were defined as 26% or more of the trees attacked for 2 successive years, and 0.3 or more attacks per square foot for 3 successive years preceding the outbreak. Future surveys may employ frequency-density relationships to predict magnitude of field populations.
Ion desolvation as a mechanism for kinetic isotope fractionation in aqueous systems

Molecular dynamics simulations show that the desolvation rates of isotopes of Li+, K+, Rb+, Ca2+, Sr2+, and Ba2+ may have a relatively strong dependence on the metal cation mass. This inference is based on the observation that the exchange rate constant, kwex, for water molecules in the first hydration shell follows an inverse power-law mass dependence (kwex ∝ m−γ), where the coefficient γ is 0.05 ± 0.01 on average for all cations studied. Simulated water-exchange rates increase with temperature and decrease with increasing isotopic mass for each element. The magnitude of the water-exchange rate is different for simulations run using different water models [i.e., extended simple point charge (SPC/E) vs. four-site transferrable intermolecular potential (TIP4P)]; however, the value of the mass exponent γ is the same. Reaction rate theory calculations predict mass exponents consistent with those determined via molecular dynamics simulations. The simulation-derived mass dependences imply that solids precipitating from aqueous solution under kinetically controlled conditions should be enriched in the light isotopes of the metal cations relative to the solutions, consistent with measured isotopic signatures in natural materials and laboratory experiments. Desolvation effects are large enough that they may be a primary determinant of the observed isotopic fractionation during precipitation.
Racial/Ethnic disparities in patient experience with communication in hospitals: real differences or measurement errors?

Background:An important aspect of medical care is clear and effective communication, which can be particularly challenging for individuals based on race/ethnicity. Quality of communication is measured systematically in the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) sur
Structured deplaning via simulation and optimization

Abstract Deplaning naturally occurs row by row down the length of an aircraft. Using simulation and optimization, we design deplaning strategies (e.g., deplane by group and/or column) that significantly reduce the overall unstructured deplaning time. The evaluations derived from a combination of optimization and simulation were tested across several equipment types using data gathered through field observations for calibration.
Emergency room vital signs and PTSD in a treatment seeking sample of motor vehicle accident survivors

Seeking to replicate earlier reports by Shalev et al. (1998) and R. A. Bryant, A. G. Harvey, R. M. Guthrie, and M. L. Moulds (2000) that elevated heart rate (HR) shortly after a trauma was predictive of later posttraumatic stress disorder (PTSD), we examined vital sign data on 74 treatment-seeking motor vehicle accident (MVA) survivors, taken in the Emergency Department (ED) following their MVAs. Contrary to expectations, we found that those with elevated HRs in the ED were significantly less likely to meet criteria for PTSD 13 months post-MVA and that those with elevated HRs had lower levels of posttraumatic stress symptoms. Likewise, those with current PTSD had lower ED values of HR and DBP than did those who did not currently meet criteria for PTSD.
Effect of Thyroxine on Lymphoid Tissue Mass of Adult Male Mice.

SummaryThe administration of thyroxine to adult male mice resulted in an increase in the organ weights of the kidneys, spleen, and peripheral lymph nodes. Similar treatment of adrenalectomized animals resulted in an increase in the weights of the spleen and peripheral lymph nodes over and above that which followed adrenalectomy alone. It is concluded that thyroxine produces an increase of lymphoid tissue mass which is independent of the rate of body growth and of the level of adrenal cortical activity.
Developing intercultural competence through global link experiences in physical education

Background: Recognition of the importance of the development of intercultural competence (ICC) has placed intense pressure on teacher education programs to infuse a global perspective into their programs. Several studies have proposed integration of global elements into teacher education programs. Although the use of online tools for telecollaboration with students and teacher educators from other countries has positively influenced certain aspects of students' ICC, there have been limited research studies which have focused on promoting ICC in physical education (PE).Purpose: This study was designed to examine the development of the ICC of PE graduate students after completion of a seven-week global link with Korean students. Deardorff's Process Model of ICC served as the foundation for gaining understanding of the development of ICC. Student responses were examined in terms of the following: types of learning, perspectives toward partners and their cultures, influences on teaching practices, and presenc...
A novel source of enterococcal endocarditis

An important element of the evaluation of patients with infective endocarditis is the determination of an infectious source. In approximately 20-45% of cases, no source is identified. Often the specific organism involved implicates the source, as is classically described by the association of S. bovis with colonic neoplasia. Other gut organisms have been reported to infect heart valves when colorectal pathology is present, but at far less frequency than S. bovis. This report deals with the case of a 75-year-old man with Enterococcus faecalis endocarditis of an unusual source--a cecal carcinoma that was causing intermittent appendiceal obstruction and infection. This case adds to previous case reports which suggest that the occurrence of enterococcal endocarditis in the absence of a classic infectious source should lead to a search for occult colorectal pathology.
MAPPING THE RISKS OF MALARIA, DENGUE AND INFLUENZA USING SATELLITE DATA

It has long been recognized that environment and climate may affect the transmission of infectious diseases. The effects are most obvious for vector-borne infectious diseases, such as malaria and dengue, but less so for airborne and contact diseases, such as seasonal influenza. In this paper, we examined the meteorological and environmental parameters that influence the transmission of malaria, dengue and seasonal influenza. Remotely sensed parameters that provide such parameters were discussed. Both statistical and biologically inspired, processed based models can be used to model the transmission of these diseases utilizing the remotely sensed parameters as input. Examples were given for modelling malaria in Thailand, dengue in Indonesia, and seasonal influenza in Hong Kong.
Using a laser range finder mounted on a MicroVision robot to estimate environmental parameters

In this article we will present a new robot (MicroVision) that has been designed at the University of Minnesota (UMN), Center for Distributed Robotics. Its design reminds of the designs of previous robots built at the UMN such as the COTS Scouts or the eROSIs. It is composed of a body with two wheels and a tail just like the two aforementioned robots. However, the MicroVision has more powerful processing and sensing capabilities and we utilized these to compute areas in the surrounding environment by using a convex hull approach. We are trying to estimate the projected area of an object onto the ground. This is done by the computation of convex hulls that are based on the data received from the MicroVision's laser range finder. Although localization of the robot is an important feature in being able to compute these convex hulls, localization and mapping techniques are only used as a tool and are not an end in this work. The main idea of this work is to demonstrate the ability of the laser carrying MicroVision robot to move around an object in order to get a scan from each side. From these scans, the convex hull of the shape is deduced and its projected area onto the ground is estimated.
Comparison of normal human skin gene expression using cDNA microarrays

Perturbations in normal wound healing may be traced to perturbations in gene expression in uninjured skin. In order to decipher normal and abnormal genetic responses to cutaneous injury, baseline gene expression in uninjured skin must first be defined. There is little data on gene expression profiles of normal human skin, i.e., which genes tend to be variable in expression and which tend to remain comparable. Therefore this study was designed to determine the degree of variability in human skin mRNA expression. Samples of normal skin were obtained from 9 healthy females undergoing breast reduction surgery. RNA was extracted, reverse transcribed into radiolabeled cDNA and hybridized onto cDNA microarrays of approximately 4400 genes. Gene expression intensities from the 9 samples were normalized and compared as a ratio of highest/lowest expression intensity. Deviation greater than 2 standard deviations from the mean of each gene was used as a cut-off. Seventy-one genes (1.7%) were substantially variable in their expression. These included genes coding for transport proteins, gene transcription, cell signaling proteins, and cell surface proteins. We found minimal variability in the matrix genes, growth factor genes and other groups of genes that are the most often studied in wound healing research. A small but definite variability in gene expression across 9 samples of clinically comparable specimens of normal skin was detected. This is in keeping with clinical observations of the variability in normal skin across individuals. These data provide high-throughput comparison of normal skin gene expression and suggest new molecules that may be studied in skin biology and perhaps, wound repair.
Klebsiella pneumoniae and type 3 fimbriae: nosocomial infection, regulation and biofilm formation

The Gram-negative opportunistic pathogen Klebsiella pneumoniae is responsible for causing a spectrum of nosocomial and community-acquired infections. Globally, K. pneumoniae is a frequently encountered hospital-acquired opportunistic pathogen that typically infects patients with indwelling medical devices. Biofilm formation on these devices is important in the pathogenesis of these bacteria, and in K. pneumoniae, type 3 fimbriae have been identified as appendages mediating the formation of biofilms on biotic and abiotic surfaces. The factors influencing the regulation of type 3 fimbrial gene expression are largely unknown but recent investigations have indicated that gene expression is regulated, at least in part, by the intracellular levels of cyclic di-GMP. In this review, we have highlighted the recent studies that have worked to elucidate the mechanism by which type 3 fimbrial expression is controlled and the studies that have established the importance of type 3 fimbriae for biofilm formation and nosocomial infection by K. pneumoniae.
Fracture Toughness/Young's Modulus Correlation for Low‐Density Fibrous Silica Bodies

Fracture toughness and static Young's modulus were measured for the low-density silica fiber materials used as tiles in the thermal protection system of the Space Shuttle. The fracture behavior was found to be in excellent agreement with a previously formulated micromechanical model and allowed both (density) classes of tile material to be correlated to a single function. A similar correlation was also found between strength and Young's modulus, which is the basis of a nondestructive evaluation test for these materials. It was shown that the value of Young's modulus determined from a dynamic test can be substantially greater than that determined in a static mechanical test. This effect must be taken into account in the correlation. Finally, it was also determined that these materials have significant variations in Kc, both within and between production units, so that the strength variability in these materials is dependent on both fracture toughness and flaw-size variations.
Observation of the strengthening of Pt layers in Ni/Pt and Pd/Pt multilayers by in-situ substrate curvature measurement

Abstract The high strength of metal multilayers may be due to small layer thicknesses and grain sizes, elastic modulus differences between components of the multilayered structure and high dislocation densities, possibly due to a large lattice mismatch between the layers. This high strength is reflected in the large stresses often observed in the individual layers of metal multilayer structures. In this study, a detailed comparison of the stress behaviors of Pt in Ni/Pt and Pd/Pt multilayers is presented. Stress is measured by monitoring the curvature of the substrate continuously during film deposition. Pt is observed to be in compression in both systems with contributions from coherency and atomic peening due to bombardment by energetic particles during the sputtering process. Pt is able to withstand a higher stress level when grown on Ni than when grown on Pd, implying that the Pt layers are stronger in the Ni/Pt multilayer. Likely causes for the observed increase in strength are the higher shear stiffness of Ni compared to Pt and the large lattice mismatch between Ni and Pt. Cross-section TEM micrographs show structural differences between Ni/Pt and Pd/Pt multilayers. The stress evolution in the Pt layers is compared to model predictions based on the Matthews–Blakeslee critical stress theory.
In prostate cancer C/EBPα promotes cell growth by the loss of interactions with CDK2, CDK4, and E2F and by activation of AKT

BACKGROUND The CCAAT/Enhancer binding protein alpha (C/EBPα) is an important transcription factor for granulopoiesis and adipogenesis. While decreased expression and mutation of C/EBPα has been found in several types of tumors, the role of C/EBPα in prostate cancer has not been well characterized. METHODS We quantitatively analyzed the immunochemical staining of prostate cancer tissue and examined the growth properties of prostate cancer cells stably expressing C/EBPα by measure growth curve, cell cycle, and anchorage independent colony formation, investigated the association of C/EBPα with E2Fs and CDKs by co-immunoprecipitation and examined the expression of CDKs and activation of AKT by Western blot analysis. RESULTS The ratio of C/EBPα expression between cancer cells close to the pseudolumen of glands and those nearer the basal cell layer was more than threefold greater than that seen in the normal prostate epithelium. Further, this ratio increased with increased Gleason score of the prostate cancer. Forced expression of C/EBPα in prostate cancer cell lines accelerated cell growth, stimulated cells into the S and G2 phases of cell cycle, and enhanced anchorage-independent colony formation. Simultaneously, forced expression of C/EBPα increased expression of CDK2/CDK4 and nuclear PP2A, and activated AKT. In addition, C/EBPα was no longer found associated with E2F1/E2F4 and CDK2/CDK4. AKT and PPA2 inhibitors restored both the anti-proliferation function of C/EBPα and the interaction between C/EBPα and E2F1/E2F4. CONCLUSION In prostate cancer cells C/EBPα cannot function as a tumor suppressor. Prostate 69: 1001–1016, 2009. © 2009 Wiley-Liss, Inc.
The effect of liver postmitochondrial fraction concentration from Aroclor 1254-treated rats on promutagen activation in L5178Y cells

Abstract L5178Y/TK+/− cells were treated with either N-acetyl-2-aminofluorene (AAF), 2-aminoanthracene (2A), benzanthracene (BA), benzo[a]pyrene (BP), 3-methylcholanthrene (3MCA), or dimethylnitrosamine (DMN) in the presence of varied concentrations (2.5–10% v/v) of liver S9 (9000 × g) postmitochondrial fraction from Aroclor 1254-dosed male CD rats. Consistent S9 concentration-dependent decreases in trifluorothymidine-resistant (TFTr) mutant induction were noted following 3 h exposure of L5178Y/TK+/− cells to either 2.5 μg/ml BP, 50 or 67 μg/ml AAF, 0.96 μg/ml 2A, 7.35 μg/ml BA, or 5.4 μg/ml 3MCA. The exception was DMN which yielded a moderate S9 concentration-dependent increase in TFTr mutant induction when L5178Y/TK+/− cells were treated for 3 h with 74.1 μg/ml DMN. Depending upon the promutagen being tested, these results suggest two different metabolic events: (1) activation via non-induced enzymes or other factors whose activities are totally S9 volume-dependent (DMN), and (2) deactivation via induced detoxification pathways, a sequence favored by increasing S9 concentration (all others). Utilization of a single “standard” (10%) concentration of liver S9 from Aroclor 1254-treated rats did not appear to provide optimal metabolic activation for 5 of these 6 promutagens.
METHANE-AIR MARKSTEIN NUMBERS FROM MEASUREMENTS OF THERMOACOUSTIC INSTABILITY

Markstein numbers characterizing the influence of stretch on the speed of thin laminar flames are determined computationally for lean and rich methane-air mixtures using results from a recent experimental study of thermoacoustic instability in a Taylor-Couette burner. A model describing the response of a thin laminar flame to acoustic flow-field excitation, which is found to exhibit dependence of thermoacoustic-instability characteristics on Markstein number, is used to determine Markstein numbers from measurements of the critical acoustic-velocity amplitudes associated with the onset of the secondary thermoacoustic instability. The model accounts for the Saffman-Taylor influence of viscosity on thermoacoustic instability for adiabatic flame propagation between closely separated walls.
The “teaching procession”? another look at teacher tenure, 1845–1925

Abstract Prior to the Great Depression the turnover rates of teachers, especially female and rural teachers, were very high. These high turnover rates have led historians to conclude that the average teacher was inexperienced and had little professional commitment. Here we examine direct evidence on teacher tenure. We find that the teacher the typical student was likely to encounter taught for more than five years in rural schools and practically a lifetime in the urban schools. Personal characteristics associated with stable job attachment in the modern era exerted a similar influence on the tenure of nineteenth-century teachers.
Effect of pressure on electron tunneling into amorphous germanium

Abstract The effect of pressure on electron tunneling through AlAl2O3(a-Ge)-Al tunnel junctions was studied between 77–300K and up to 60kbar where a-Ge is known to undergo a pressure-induced semiconductor-metal transition. About 1000 A thick evaporated a-Ge and an effective junction area of 4 × 10−4cm2 were used. A Drickamer high pressure cell adapted for cryogenic measurements was employed. The bias dependence of the differential tunnel conductance G(V) is essentially symmetric with a minimum at V = 0. We find G (0) = G exp [-( T 1 / T ) 1 4 ] and for the conductivity δ = δ exp [-( T 0 0 / T ) 1 4 ] with T1 = 0.01 T0 instead of the predicted relation T1 = 2T0. Between 0–60kbar G(0) increases by 103 at T = 300K. T0 and T1 decrease slightly above 30kbar. We conclude that interface states play an important role in tunneling.
SU‐FF‐T‐27: A Monte Carlo Based Tumor Model

Purpose: To develop a stochastic, radiobiological tumormodel to conduct in silico simulations of cell proliferation and to quantitatively assess biological effects of delivered dose and different irradiation regimes. Method and Materials: We developed a Monte Carlomodel to perform computer simulations on initial tumorgrowth, progression of predetermined cell distributions and cellular response to irradiation following the linear‐quadratic model. The single‐cell‐based configuration is composed of a volumetric grid lattice, with each grid site representing a capillary, clonogenic or normal tissuecell. Mean values for biological parameters such as cell cycle time and cell cycle phase dependent radiosensitivity were adopted from literature and sampled restrictively from Gaussian distributions for each cell. Additionally, angiogenesis, apoptosis and necrosis were implemented and random processes like cell displacement after proliferation and radiation‐induced DNA damages were modeled using probability density functions.Results: Simulations of initial tumor formation and ongoing proliferation illustrate a decelerated growth rate with increasing cell cycle times and hypoxia occurrence, whereas low thresholds for capillary stimulation through tumor angiogenesis factors lead to accelerated proliferation. Analyses of tumor response to different fractionation patterns show faster and stronger expression of necrosis after accelerated time‐dose‐patterns. A benchmark against published experimental data with human HNSCC‐6 tumorcell lines demonstrates good quantitative agreement. Conclusions: Our model is able to qualitatively predict basic radiobiological behavior and implicitly includes the ‘four Rs of radiotherapy’ as a result of the cellular approach. In order to apply the model to a specific tumor, it has to be tuned by including in vivo data and benchmarked against experiments. Given the adequate biological input parameters, good quantitative agreement can be achieved. This model could be enhanced to help predicting treatment response and bring us one step closer to biological optimization models.
Alternative Fuels in Gas Turbine Applications: A Simple Method for Assessing the Influence of Fuel on Performances

Gas turbines have by essence access to a broad range of primary energies. This advantage is essentially exploitable by the Heavy Duty branch which, thanks to moderate compression ratios, robust mechanical designs and versatile combustion systems, can utilise a wide series of commercial and process by-products fuels: natural gas, petroleum distillates, gasified coal or biomass, gas condensates, ash-forming fuels, alcohols etc. In this context, a thorough knowledge of the many-facetted fuel/machine interdependency, which seems insufficiently covered by the existing literature on gas turbines, is of prime interest.This paper is devoted to the thermodynamic aspects of fuel influence. It offers: (i) a review of the main primary energies accessible to stationary gas turbines, (ii) a new, differential method for assessing the impact of fuel on machine thermodynamics, with original equations accounting for the changes in power output, efficiency and exhaust heat.Copyright © 2000 by ASME
Social motives and the interaction between descriptive and injunctive norms in college student drinking.

Objective: Social norms are a key determinant of young adult drinking, yet little research has evaluated potential interactive effects among different types of norms. The present research was designed to evaluate perceptions of friends' approval of drinking (i.e., injunctive norms) as a moderator of the relationship between perceived prevalence of friends' drinking (i.e., descriptive norms) and personal alcohol consumption. We also evaluated whether social drinking motives further influence this relationship. Method: Participants included 1,400 first-year college students (61% women) who completed Web-based assessments of descriptive and injunctive norms, personal drinking, and social drinking motives. Results: Results revealed that both descriptive and injunctive norms regarding close friends were uniquely and positively associated with drinking behavior. The relationship between perceived descriptive norms and personal alcohol consumption was stronger among those who also perceived their friends as bein...
Axisymmetric Transonic Turbulent Base Pressures

R studies of incompressible and transonic separated flow problems* led to the development of a model accounting for the viscid-inviscid interaction within these flow regimes. It is stipulated that the inviscid flowfield is produced from an equivalent body whose geometry can be characterized by certain parameters. The inviscid flow so established guides the viscous flow processes of mixing and recompression along the wake, including the subsequent reattachment and flow redevelopment in the sense of boundary-layer concept. The viscid-inviscid interaction is manifested by the fact that the characteristic parameters required to establish the corresponding inviscid flow are determined through the viscous flow considerations. Extension of this approach to study the base pressure of a transonic flow past a backward facing step in axisymmetric configuration is reported and discussed.
Sleep allostasis in chronic sleep restriction: The role of the norepinephrine system

Sleep responses to chronic sleep restriction may be very different from those observed after acute total sleep deprivation. Specifically, when sleep restriction is repeated for several consecutive days, animals express attenuated compensatory increases in sleep time and intensity during daily sleep opportunities. The neurobiological mechanisms underlying these adaptive, or more specifically, allostatic, changes in sleep homeostasis are unknown. Several lines of evidence indicate that norepinephrine may play a key role in modulating arousal states and NREM EEG delta power, which is widely recognized as a marker for sleep intensity. Therefore, we investigated time course changes in brain adrenergic receptor mRNA levels in response to chronic sleep restriction using a rat model. Here, we observed that significantly altered mRNA levels of the α1- adrenergic receptor in the basal forebrain as well as α2- and β1-adrenergic receptor in the anterior cingulate cortex only on the first sleep restriction day. On the other hand, the frontal cortex α1-, α2-, and β1-adrenergic receptor mRNA levels were reduced throughout the period of sleep restriction. Combined with our earlier findings on EEG that sleep time and intensity significantly increased only on the first sleep restriction days, these results suggest that alterations in the brain norepinephrine system in the basal forebrain and cingulate cortex may mediate allostatic changes in sleep time and intensity observed during chronic sleep restriction.
A probabilistic model for the MRMC method, part 1: theoretical development.

Rationale and Objectives Current approaches to receiver operating characteristic (ROC) analysis use the MRMC (multiple-reader, multiple-case) paradigm in which several readers read each case and their ratings (or scores) are used to construct an estimate of the area under the ROC curve or some other ROC-related parameter. Standard practice is to decompose the parameter of interest according to a linear model into terms that depend in various ways on the readers, cases, and modalities. Though the methodologic aspects of MRMC analysis have been studied in detail, the literature on the probabilistic basis of the individual terms is sparse. In particular, few articles state what probability law applies to each term and what underlying assumptions are needed for the assumed independence. When probability distributions are specified for these terms, these distributions are assumed to be Gaussians. Materials and Methods This article approaches the MRMC problem from a mechanistic perspective. For a single modality, three sources of randomness are included: the images, the reader skill, and the reader uncertainty. The probability law on the reader scores is written in terms of three nested conditional probabilities, and random variables associated with this probability are referred to as triply stochastic. Results In this article, we present the probabilistic MRMC model and apply this model to the Wilcoxon statistic. The result is a seven-term expansion for the variance of the figure of merit. Conclusion We relate the terms in this expansion to those in the standard, linear MRMC model. Finally, we use the probabilistic model to derive constraints on the coefficients in the seven-term expansion.
Monte Carlo Calculation for Electromagnetic-Wave Scattering from Random Rough Surfaces

A Monte Carlo calculation for light intensities scattered from a random Gaussian-correlated surface is presented for the first time. It is shown that small randomness on a grating surface can considerably change the intensities and, in particular, the surface polariton resonances. These results should be used to check perturbation-theory calculations.
The role of neurolytic sympathetic blocks in treating cancer pain

Over 10 million Americans live with cancer and almost 1.5 million new cases of cancer will be diagnosed in 2009. Many of these patients will have severe pain even with optimal medical management. These patients may be offered advanced interventional procedures to manage their pain. For pain originating from the viscera, chemical neurolysis of the sympathetic nervous system may be an appropriate intervention. Common techniques employed to interrupt the sympathetic nervous system would include the celiac plexus block, the superior hypogastric plexus block, and the ganglion impar block. This article offers a discussion of the patient selection, indications, complications, and technical aspects of these pain-relieving interventions. For these patients with refractory cancer-related pain, minimally invasive, percutaneous neurolytic blocks have the potential to provide significant pain reduction and an overall improvement in their quality of life.
Depth Variation of Tritium and Argon-37 Produced by High-Energy Protons in Iron

The ${\mathrm{H}}^{3}$ produced by 0.16-, 1.0-, 3.0-, and 6.2-Bev protons and the ${\mathrm{A}}^{37}$ by 0.16-, 1.0-, and 6.2-Bev protons in long iron targets is measured as a function of depth. The maximum effective ${\mathrm{H}}^{3}$ cross section is 7.2 mb at 0.16 Bev, 60 mb at 1.0 Bev, 100 mb at 3.0 Bev, and 130 mb at 6.2 Bev. The maximum effective ${\mathrm{A}}^{37}$ cross section is 0.19 mb at 0.16 Bev, 4.7 mb at 1.0 Bev, and 6.7 mb at 6.2 Bev. The depth variation of these isotopes is very energy-dependent. At the higher energies a slight transition effect occurs. At the lower energies there is an exponential decrease with depth. The comparison of these measurements with the depth variation of ${\mathrm{He}}^{3}$ in the Carbo meteorite shows that the cosmic rays that produced the ${\mathrm{He}}^{3}$ in this material were very similar to the protons with 6-Bev energy. The ${\mathrm{H}}^{3}$ to ${\mathrm{A}}^{37}$ ratio is not very energy- or depth-dependent. The ratio is 15 at 1 Bev and 20 at 6.2 Bev. However, for 0.16-Bev protons the ${\mathrm{H}}^{3}$ to ${\mathrm{A}}^{37}$ ratio increases from 40 to 1000 in 4-cm depth. The ${\mathrm{H}}^{3}$ to ${\mathrm{A}}^{37}$ ratio is compared with the ${\mathrm{He}}^{3}$ to ${\mathrm{A}}^{36}$ ratio in four iron meteorites. These are comparable to a remarkable extent with the Bev proton results. The small variation of the ${\mathrm{He}}^{3}$ to ${\mathrm{A}}^{36}$ ratio in meteorites is related to the fact that the ${\mathrm{H}}^{3}$ to ${\mathrm{A}}^{37}$ ratio is not very energy- or depth-sensitive for protons in the Bev range; however, the ${\mathrm{He}}^{3}$ to ${\mathrm{A}}^{36}$ ratio also favors the 6-Bev energy.
Dental involvement in histiocytosis

Abstract Fifty consecutive patients with histiocytosis were studied for dental involvement of this symptom complex. More than one third had oral manifestations of this disease, and 16 per cent had a chief complaint of oral pain. Since lesions associated with gingiva, jawbones, and teeth are often seen either as the first manifestation of histiocytosis or as a complication of the disease, the dentist is implicated in the diagnosis and management.
Glare and contrast sensitivity testing in cataract patients

I measured contrast sensitivity and glare in 51 cataract patients who had Snellen visual acuities of 20/60 or better. The VCTS contrast sensitivity plates, the Miller-Nadler glare tester, Baylor visual function tester, and the Stereo Optical glare tester were used. Patients indicated that the Baylor visual function tester most closely reproduced their daytime glare symptoms and that the Stereo Optical glare tester most closely reproduced their nighttime glare symptoms. Scores on the Stereo Optical glare tester and VCTS contrast sensitivity chart statistically were most strongly correlated with patients' complaints and the severity of their lens opacities. Contrast sensitivity and glare testing are important adjuncts in evaluating patients who have visual complaints and yet have good Snellen acuities.
Edouard Bourdet's career in New York

(1950). Edouard Bourdet's career in New York. Speech Monographs: Vol. 17, No. 3, pp. 209-226.
Comparison of the effects of mianserin and its enantiomers and metabolites on a behavioral screen for antidepressant activity.

The behavioral effects of racemic mianserin, its (+) and (−) enantiomers, and its metabolites desmethylmianserin and 8-hydroxymianserin were evaluated on the differential-reinforcement-of-low-rate 72-s (DRL 72-s) schedule, a screen known to be sensitive to and specific for the antidepressant properties of drugs. Racemic mianserin produced the antidepressant-like effect (increased reinforcement rate, decreased response rate) at 5 and 10 mg/kg. The mianserin enantiomers showed the antidepressant-like effect beginning at lower doses [(+) mianserin; 0.6 mg/kg; (−) mianserin: 2.5 mg/kg]. The mianserin metabolites showed no clear dose-related effect at doses up to 10 mg/kg. It is concluded that the antidepressant-like effects of mianserin are due to the activity of the parent compound rather than to its metabolites, and that they may be primarily attributable to the (+) enantiomer. The greater potency of (+)-mianserin may be related to its higher affinity for the 5-HT2 receptor.