cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of solids concentration on evaporative liquid jets in gas-solid flows

Abstract Microstructures of evaporative liquid spray jets in gas–solid flows can be significantly altered by the variation of the solids concentration in gas–solid suspensions. In this study, experiments are conducted to illustrate the effect of the solids concentration on some aspects of microstructures of evaporative liquid jets, especially the jet evaporation length. The study indicates that, due to turbulence mixing and phase interactions among gas, solids, and evaporative droplets, the evaporation length can be shortened by as much as 45% with the solids concentration of 1.6%, compared to that in the solids-free flow. It also indicates that the thermocouple measuring technique is an effective one for determining the evaporation length of the jet.
Acidic groups in coal and coal-derived materials

Abstract The application of non-aqueous titrations to coal and coal-derived liquids is described to distinguish and determine carboxylic and phenolic groups in these materials. Such titrations have been applied to two coals, a subbituminous and a bituminous coal. For the subbituminous coal the amount of phenolic groups estimated from non-aqueous titrations is only about 30% of that estimated from acetylation studies, whereas both these methods give similar results for the bituminous coal. The lower values obtained by non-aqueous titrations, for the subbituminous coal, are due to proximal phenolic groups which are only partially titratable and alcohol groups which are non-titratable.
Exposure to the stressor environment prevents the temporal dissipation of behavioral depression/learned helplessness.

Abstract Background: Exposure to uncontrollable stressors such as inescapable shock (IS) produces a set of behavioral changes such as poor escape learning that have been called behavioral depression and learned helplessness. This paradigm has been proposed to be a model of depression and of anxiety-related disorders such as posttraumatic stress disorder (PTSD). However, the behavioral changes persist for only a few days after the stressor, rendering the phenomenon questionable as a model. However, the original traumatic experience is re-experienced in PTSD and rumination occurs in depression. In a series of experiments we therefore sought to determine whether behavioral depression/learned helplessness could be made to endure by periodically "reminding" the subject of the original IS experience. Methods: Rats exposed to IS were tested for escape learning at various times thereafter. In different experiments the subjects were exposed to the environment in which IS had occurred at differing points in the interval between IS and escape testing. Results: Exposure to the environment in which IS had occurred prolonged the duration of behavioral depression/learned helplessness, and repeated exposures prolonged it indefinitely. This effect required exposure to the cues that had been present during IS (i.e., reminding) and was not duplicated by exposure to other stressors or stress environments. Conclusions: Behavioral depression/learned helplessness can be maintained over time by processes that may be similar to those occurring in depression and PTSD, thereby strengthening the possibility that this paradigm is indeed a reasonable model of these disorders.
Confidence intervals on linear combinations of variance components that are unrestricted in sign

A new method is proposed for constructing confidence intervals on where the sign of γ is unrestricted and unknown, and are independently distributed chi-squared random variables with ni degrees of freedom for Computer simulation is used to illustrate that the method provides a confidence coefficient that is generally close to the stated level. The method is illustrated by using it to test a main effect in a random three-factor crossed design.
Multivariate Methods in Engineering Anthropometry

Engineers and scientists have known for at least 45 years that univariate descriptive statistics, particularly percentiles, are inappropriate for use in designs that involve more than one dimension. Yet, the non-existent 5th percentile woman, and 95th percentile man are commonly referred to in the literature today. Arguments against using percentiles are numerous and compelling. It has been demonstrated that: 1) they will not ensure the accommodation of the desired population, 2) they are not additive so they will result in strangely proportioned models, and 3) they result in designs that waste materials. The source of the problem is the fact that they are univariate (one-dimensional) statistics applied to multivariate (many dimensional) situations. The primary argument for using percentiles has been that there were no alternatives. In this symposium we seek to remedy that. The speakers in this symposium will describe, compare, contrast and demonstrate some of the multivariate alternatives they have been ...
Static analysis for dynamic coupling measures

Coupling measures have important applications in software development and maintenance. They are used to reason about the structural complexity of software and have been shown to predict quality attributes such as fault-proneness, ripple effects of changes and changeability. Traditional object-oriented coupling measures do not account for polymorphic interactions, and thus underestimate the complexity of classes and fail to properly predict their quality attributes.To address this problem Arisholm et al. [3] define a family of dynamic coupling measures that account for polymorphism. They collect dynamic coupling measures through dynamic analysis and show that these measures are better indicators of complexity and better predictors of quality attributes than traditional coupling measures.This paper presents a new approach to the computation of dynamic coupling measures. Our approach uses static analysis, in particular class analysis, and is designed to work on incomplete programs. We perform experiments on several Java components and present a precision evaluation which shows that inexpensive class analysis such as RTA computes dynamic coupling measures with almost perfect precision. Our results indicate that inexpensive static analysis may be used as a more convenient, more practical and more precise alternative to dynamic analysis for the purposes of computation of dynamic coupling measures.
Counterspaces: A Unit of Analysis for Understanding the Role of Settings in Marginalized Individuals’ Adaptive Responses to Oppression

Research and theory on the intervening variables that enable individuals who experience marginalization and oppression to achieve well-being have historically relied on an individual level of analysis. Yet, there is a growing body of literature that highlights the roles that contexts play in facilitating processes that result in wellness among marginalized individuals. This paper proposes a conceptual framework that highlights a specific type of setting, referred to as “counterspaces,” which promotes the psychological well-being of individuals who experience oppression. Counterspaces are theorized to enhance well-being by challenging deficit-oriented societal narratives concerning marginalized individuals’ identities. The conceptual frame proposed here suggests that “challenging” can occur through at least three processes: (1) narrative identity work, (2) acts of resistance, and (3) direct relational transactions. This paper articulates each of these challenging processes. Additionally, the utility of using the Counterspaces framework for thinking critically about and investigating how settings—and the transactional processes that unfold within them—are associated with the promotion of psychological wellness for various marginalized populations is discussed.
Cortisol levels in relation to hippocampal sub-regions in subjects with first episode schizophrenia

The etiology of hippocampal volumetric reductions in schizophrenia is largely unknown. In addition to genetic factors, environmental factors might also play a role. High levels of glucocorticoids are known to affect hippocampal volume in disorders such as Cushing's syndrome, but the relationship between cortisol and hippocampal volumes has not been studied in schizophrenia. We obtained diurnal salivary cortisol levels and MRI images to explore the link between cortisol levels and regional hippocampal volumes in healthy controls (N=29) and subjects with first episode schizophrenia (N=16) at the time of first admission. T1-weighted coronal MR images (slice thickness=1.5 mm) were acquired through the whole head using a 3D Fast SPGR IR Prep sequence on a 1.5 T GE imaging system. Using ANOVA, cumulative daily cortisol exposure calculated as area under the curve for each subject revealed significantly higher cortisol levels in the patient group [F(1,43)=4.4 p=0.04]. However, there were no statistically significant associations between the cortisol measures and regional hippocampal volumes in the subjects, except a trend level link between anterior hippocampal volume and cortisol in the positive direction, in parallel to previous findings in healthy adolescents. Our findings do not suggest a robust association between cortisol levels and hippocampal volumes in a first episode schizophrenia sample. Larger scale studies are needed to conclude a link between the two measures, yet it is possible that the negative association that was previously shown in other disorders may not apply to schizophrenia.
Bleeding gastric varices: stick to the sticky glue.

In this prospective seminal study from Taiwan 74 cirrhotic patients with histories of gastric variceal bleeding were randomized to two groups. The group receiving endoscopic variceal obturation with butyl cyanoacrylate (GVO) comprised 31 patients, and the group receiving pneumatic-driven variceal ligation (GVL) comprised 29 patients. Treatment was repeated regularly until obliteration of gastric varices. All patients received emergent endoscopy within 12 h of admission to Kaohsiung Veterans General Hospital. The inclusion criteria of this study were that patients were cirrhotic, had histories of gastric variceal bleeding, and were between 20 and 70 yr of age. The definition of gastric variceal bleeding included 1) active spurting or oozing of blood from gastric varices during endoscopy and 2) stigmata of recent hemorrhage such as blood clots coating the gastric varices or the presence of hematocystic spots or white nipples on gastric varices. The exclusion criteria were 1) undetermined origin of bleeding from esophageal varices or gastric varices; 2) presence of deep jaundice (serum bilirubin > 10 mg/dl), hepatic encephalopathy, or hepatorenal syndrome; 3) association with advanced hepatocellular carcinoma, Okuda stage III, uremia, cerebrovascular accident, or other debilitating disease; 4) history of sclerotherapy or shunt operation; and 5) life expectancy < 24 h. Active bleeding occurred in 15 patients in the GVO group and 11 patients in the GVL group. The initial hemostasis rates (defined as no bleeding for 72 h after treatment) were 87% in the GVO group and 45% in the GVL group (p = 0.03). In both groups the sessions required to achieve variceal obliteration and obliteration rates were similar. However, rebleeding rates were significantly higher in the GVL group (54%) than in the GVO group (31%) (p = 0.0005). Treatment-induced ulcer bleeding was four times more common in the GVL group than in the GVO group (28% vs 7%, p = 0.03). The amount of blood transfusions was also higher in the GVL group (4.2 ± 1.3 U vs 2.6 ± 0.9 U) (p < 0.01). Twenty-nine percent of the GVO group patients died, compared to 48% of the GVL group (p = 0.05). The authors concluded that endoscopic obturation using cyanoacrylate was more effective and safer than band ligation in the management of bleeding gastric varices.
The effect of zinc and copper oxides and other zinc compounds as fillers on the tribological behavior of thermosetting polyester

Abstract The tribological behavior of thermosetting polyester filled with CuO, ZnO, ZnF 2 , and Zn(C 18 H 35 O 2 ) 2 fillers was studied. Sliding was performed in ambient atmosphere at 1.0 m s −1 between a polyester pin and a hardened tool steel disk in a pin-on-disk machine. The worn and the unworn specimen pin surfaces, zinc stearate powder, and the transfer films formed during sliding were studied by X-ray photoelectron spectroscopy (XPS). It was found that the coefficients of friction of all the filled composites were higher than that of the unfilled polyester. As for wear, the wear rate of polyester filled with ZnO and ZnF 2 increased while that of polyester filled with CuO and Zn (C 18 H 35 O 2 ) 2 decreased. The reasons for these kinds of behavior were investigated. XPS results revealed that the Zn(C 18 H 35 O 2 ) 2 filler decomposed during the sliding process while ZnO did not. It has been hypothesized that decomposition of the filler helps in bonding of the transfer film to the counterface. The observed behavior is explained in terms of the topographical features, morphology and bonding of the transfer film to its counterface.
SrHfO3 as gate dielectric for future CMOS technology

Thin epitaxial films of the high-@k perovskite SrHfO"3 were grown by molecular beam epitaxy on Si(100) and investigated by ellipsometry and X-ray photoelectron spectroscopy to determine its band gap and valence band offset. Conducting AFM shows a good correlation between topography and current mapping, pointing to direct tunneling conduction. Long channels MOSFETs with low equivalent oxide thickness (EOT) were fabricated and their channel mobility measured. Mobility enhancement can be achieved by post processing annealing in various gases but at the cost of interfacial regrowth. An alternative approach is to increase mobility without changing EOT is by electrically stressing the gate dielectric at ~150 ^oC.
Interpretation of the mechanism of catalytic reductions with colloidal rhodium in the liquid phase.

Abstract 1. 1. A method is given for the preparation of a stable, highly active rhodium-polyvinyl alcohol catalyst. 2. 2. The application of this catalyst to the hydrogenation of organic substrates containing the carbon-carbon double bond or the nitro, carbonyl, and nitrile groups, is described. 3. 3. Rhodium and palladium are compared with regard to their behavior in the hydrogenation of the above-mentioned substrates and their sensitivity to changes in pH. 4. 4. A systematic kinetic study is instituted on the reduction of a series of propylene derivatives and of p - and m -substituted nitrobenzenes. 5. 5. The experimental results are interpreted electronically and the hypothesis is proposed that rhodium acts through the formation of an intermediate complex involving “ionic” hydrogen.
New results on entangled translucent eavesdropping in quantum cryptography

We present a mathematical physics analysis of entangled translucent eavesdropping in quantum cryptography, based on the recent work of Ekert, Huttner, Palma, and Peres. The key generation procedure involves the transmission, interception, and reception of two nonorthogonal photon polarization states. At the receiving end, a positive operator valued measure (POVM) is employed in the measurement process. The eavesdropping involves an information-maximizing von Neumann-type projective measurement. We propose a new design for a receiver that is an all-optical realization of the POVM, using a Wollaston prism, a mirror, two beam splitters, a polarization rotator, and three photodetectors. We present a quantitative analysis of the receiver. We obtain closed-form algebraic expressions for the error rates and mutual information, expressed in terms of the POVM-receiver error rate and the angle between the carrier polarization states. We also prove a significant result, namely, that in the entangled translucent eavesdropping approach, the unsafe error rate based on standard mutual information comparisons is equivalent to the maximum allowable error rate based on perfect mutual information for the eavesdropper. In this case, the above unsafe error rate is in fact not overly conservative.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Damage development in carbon/epoxy laminates under quasi-static and dynamic loading

Abstract The contrasting characteristics of damage evolution have been examined in a multidirectional carbon/epoxy composite laminate (IM7/8551-7) subjected to both quasi-static and dynamic loading. Our experiments were performed on bend-test bars that were loaded either in ‘supported' four-point bending or under ‘unsupported' conditions with a Hopkinson pressure bar to induce dynamic loading. We found differences in the damage that occurred in specimens loaded by the two techniques, in terms of the number of cracks and the length of the cracks. In the case of quasi-static loading, there were many matrix cracks within individual plies and only a few delamination cracks between plies; the maximum ratio of numbers of matrix to delamination cracks observed was 6:1. Despite their small number, the delamination cracks had a greater total length than the matrix cracks, and specimen failure occurred as a result of delamination crack propagation. During dynamic loading, the ratio between numbers of matrix and delamination cracks was 3:1, and in this case the ratio between the total crack lengths was unity. A quantitative assessment of damage induced during quasi-static bending was made from specimen stiffness results. Using simple beam theory and knowing the location of the damage, we correlated beam stiffness to the materials effective elastic modulus. We found that the composite's effective modulus decreased rapidly with small amounts of initial damage, but that subsequent increases in damage decreased the effective modulus at a much lower rate.
Kendall’s tau and kendall’s partial correlation: two BASIC programs for microcomputers

Nonparametric rank-ordercorrelationprocedures, such as Spearman's rho and Kendall's tau, are often used as alternativesto Pearson's r, their parametric counterpart, when assumptions underlying that procedure cannot be met. Kendall's tau is a particularly useful alternative in that it may be generalizedto a partial correlation coefficient. This article describes an easy-to-use BASIC program for the calculationof both Kendall's tau and Kendall's partial rank correlation coefficient. Kendall's tau. The tau procedure, like mostother nonparametricprocedures, requiresat leastordinal leveldata and assumesthat these data have been drawn from distributionsthat are continuous. The 5 statistic, a measureof disarray, represents the numerator term in the tau procedure. The sampling distributions of 5 and tau are identical in a probability sense (Hays, 1972). Therefore, the significance of tau maybe determined by referring to either. Kendall has determined the exact sampling distribution of 5 for N=4 to N= 10 (Kendall, 1970). For N<?10 the distribution of 5 is closeto normal, and a normalapproximationto the exact distributionof 5 may be determined. Employing an algorithm presented by Brophy (1986), the program applies a significance test by dividing 5 by the standarddeviationof the samplingdistributionto obtain Z, the normal deviate. The approximate probability of Z is then computedby applying the formula presented by Poole and Borchers (1977). Kendall's partial correlation. A correlation between two variables, X and Y, may be a functionof each variable's association with a third variable, Z. Stated simply, partial correlation eliminatesany effects of variation by Z uponthe relationship betweenXand Y. Partial correlation, therefore, presumablyallowsone to assess the relationship between X and Y without the effects of Z. Although Kendallpresented tau;.• for the specialcase in whichno ties exist, Hawkes(1971)showedit to be appropriate as well for the case in which ties do exist. The majordrawback to thisprocedureis that the sampling distribution for tau;... unlike that for tau, has not yet been determined; there are, therefore, no tests of significance for the partial rank correlation coefficient at this time. In the present program the Kendall partial rank correlation (tau;.•) may be computed from raw score triads, three individual setsof raw scoredyads, or pairwise corre-
Multiple equilibrium under CES preferences

Under the simplifying assumptions that (1) there are two commodities and two agents, (2) production (endowment) of each commodity per period is fixed, (3) preferences of the two agents are of CES type, and (4) both the endowments and the CES preferences are mirror images of each other (called “supersymmetry”), it is shown that (a) there always exists a symmetric equilibrium with a unit price ratio, (b) a sufficient condition for the stability (hence uniqueness) of this symmetric equilibrium is that the elasticity of substitution satisfy $${\sigma\geqq 1/2}$$ , and (c) multiple (triple) equilibrium is possible if and only if each agent has a relative preference for the good that is sold (“exported”) to the other agent. Further conditions for multiple equilibrium are derived.
Inhibition of Alveolar Neutrophil Immigration in Endotoxemia Is Macrophage Inflammatory Protein 2 Independent

Abstract Background. Altered transendothelial migration and delayed apoptosis of neutrophils (PMN) have been implicated as contributing to infection in patients with gram-negative sepsis. Macrophage inflammatory protein 2 (MIP-2) signals PMN immigration and may alter other PMN functions. We tested the hypothesis that sequential endotoxin challenge in vivo alters PMN apoptosis and chemotactic responses. Materials and methods. Endotoxemia was induced in male Wistar rats (250 g) via intraperitoneal (IP) administration of LPS (4 mg/kg). After 18 h, intratracheal (IT) injection of LPS (400 μg/kg) was performed. Control animals received saline injections. Four hours after IT-LPS, circulating and bronchoalveolar lavage (BAL) PMN were isolated. PMN yields were calculated, and apoptosis was quantified after 18 h in culture by annexin V–fluorescein isothiocyanate FACS analysis. BAL MIP-2 concentrations were determined by ELISA. PMN chemotaxis to MIP-2 and IL-8 was determined using a fluorescent in vitro migration assay. Results. Endotoxemia (IP-LPS) significantly decreases BAL PMN yield in response to an in vivo IT-LPS challenge. IT-LPS inhibits BAL PMN apoptosis to the same extent as sequential IP/IT-LPS. Alveolar MIP-2 concentrations are similar in the two groups. In vitro migration to IL-8 and MIP-2 was inhibited in PMN from endotoxemic versus control animals. Conclusions. These data demonstrate that endotoxemia inhibits PMN migration despite similar MIP-2 concentrations in the alveolus. Sequential insults do not affect the inhibition of apoptosis. In vitro, PMN from endotoxemic animals display impaired chemotaxis to MIP-2 and interleukin-8. This may result in an inadequate host defense that contributes to increased ICU-acquired pneumonia in septic patients.
Mechanisms of systemic hypertension during acute elevation of intraabdominal pressure.

Abstract Introduction. In previous studies we described mechanisms by which acute elevation of the intraabdominal pressure (IAP) induces intracranial hypertension (ICHTN). Here we sought to define the role of ICHTN in mediating systemic hypertension (HTN) during CO 2 pneumoperitoneum (PNP). Methods. Six large animals (swine) were hyperventilated to buffer hypercarbia. Intracranial pressure (ICP) was monitored with a Camino intraparenchymal ICP monitoring system. A Foley catheter was introduced intracranially via a separate burr hole. At phase 1, changes in ICP, central venous pressure (CVP), and mean arterial pressure (MAP) were recorded during periods of CO 2 PNP at IAP levels of 15, 20, 25, and 30 mm Hg. At phase 2, ICHTN was produced directly by inflating the intracranial balloon to the same ICP levels that had been measured in phase 1 for each degree of IAP. CVP and MAP were recorded. Repeated measures analysis of variance was applied. Results. At phase 1, the mean ΔCVP, ΔICP, and ΔMAP increased relative to the degree of IAP ( P = 0.0001, 0.0004, and 0.024, respectively). At phase 2, the increments in ΔMAP were significant ( P = 0.024) and in the same direction and amplitude as at phase 1. Conclusions. In this study, increasing the IAP with CO 2 PNP with a consequent increase of ICP and direct manipulation of the ICP produced a comparable systemic HTN. We believe that this further supports our hypothesis: Elevated IAP produces an immediate increase in the CVP, which impairs venous drainage from the central nervous system (CNS), increases the ICP, and initiates a CNS-mediated response and systemic HTN.
The effect of dust retention on pressure drop in a high velocity pulse-jet fabric filter

Abstract Pulse-jet fabric filters exhibit abnormally high pressure drops when operated at higher than normal superficial filtration velocities. The causes of high pressure drop are investigated for a pilot scale pulse-jet filter collecting fly ash at 50, 75, 100, 125 and 150 mm/s filtration velocities. The measured equilibrium pressure drops ranged from 0.35 kPa (1.4 in. H2O) at low velocity to 10.2 kPa (40.8 in. H2O) at high velocity. Retention of a large mass of dust on the fabric was found to have a significant effect on equilibrium pressure drop at all the tested filtration velocities. The dust deposit's distribution, total mass, and specific resistance (K2) all remained essentially constant at lower filtration velocities, but changed dramatically at the highest test velocity. At the 150 mm/s velocity the total dust mass doubled, the dust distribution equalized over the surface of each bag, and K2 increased by a factor of 4.7.
Intraorganizational power considerations for designing information systems

Abstract Organizations may be viewed as shifting political coalitions competing for organizational resources. Control over the administration and distribution of information is one means for influencing the distribution of intraorganizational power. Both accountants and MIS staff share this ability to acquire power for themselves and affect a redistribution of power among their users. In this paper the vertical, horizontal and information services perspectives of power are discussed. Propositions for redistributing power are suggested and impacts from changing information services technology are evaluated.
A simple procedure for making stereotaxic lesions in the mouse.

Abstract A simple device for making stereotaxic brain lesions or administering electrical brain stimulation in the mouse, without placing the mouse in a stereotaxic apparatus, is described. The entire operative procedure takes approximately one min.
Wood and bark anatomy of lianoid Indomalesian and Asiatic species of Gnetum

Abstract Quantitative and qualitative data on wood and bark are offered for 11 species of lianoid Indomalesian and Asiatic species ofGnetumsectionCylindrostachys. Material of roots was studied for two species, material of an underground stem for one species, and stem material was studied for all species; wood from inside and outside of a large stem ofG. montanumwas analysed (quantitative data do not change with age in this species). Roots have shorter, narrower vessel elements, more numerous per mm2, compared with those of stems; these trends run counter to those in dicotyledons. Roots and underground stems have more abundant parenchyma and less abundant sclerenchyma than do stems. Parenchyma of both roots and stems is rich in starch. All of the species studied here have both fibre-tracheids and tracheids, but tracheids are not distributed vasicentrically as they are in dicotyledons. Tori are reported for tracheary elements of three species studied here. Vasicentric axial parenchyma (which usually is thick–walled) is present in all species; thick or thin-walled diffuse or diffuse-in-aggregates apotracheal parenchyma is present in almost all of the species studied. Rays are mostly dimorphic in size, but show various conditions with respect to wall thickness, sclerenchyma presence, and crystal presence. As in other lianoid species ofGnetum, the species of the present study show origin of lateral meristem activity in parenchyma of the innermost cortex. Cortex and bark of the species studied here are relatively uniform in distribution of gelatinous fibres, nests of sclereids, the cylinder of brachysclereids that extends around the stem, and sclerenchymatous phelloderm. Laticifers were observed in bark of only two species studied. Although a few species characters are evident, the species that comprise SectionCylindrostachysdiffer from each other mostly in degree rather than in presence or absence character state distributions. Secretory cavities are newly reported for the genus.
LiGA measurement and acceptance evaluation

In support of establishing production capability of Lithographie Galvanoformung Abformung (LiGA) technology at the Honeywell Federal Manufacturing and Technologies (FM&T), also known as the Department of Energy (DOE) Kansas City Plant (KCP), measurement and acceptance techniques were evaluated on micro-miniature mechanical prototype components. Four nickel (Ni) prototype components, which were fabricated, required ±10 μm dimensional tolerance, 10 μm contours, and had to meet specific metallurgical requirements. These requirements pushed the KCP measurement and acceptances processes to their limit. The measurement techniques used to support the prototype work and the new technologies being considered from lessons learned to support future LiGA activities are described. This work was completed jointly with Sandia National Laboratories and supports future production needs for the Department of Energy.
Clonal attenuation in chick embryo fibroblasts. Experimental data, a model and computer simulations.

When cells from mass cultures of chick embryo fibroblasts are grown at very low density, some cells yield large clones while others produce smaller clones, and some cells fail to divide at all. the distribution of clone sizes is related to the number of population doublings which the donor mass culture has undergone: the more doublings which have occurred, the smaller the average clone size. In this report we describe a model which analyses this phenomenon, referred to as ‘clonal attenuation’, in detail. The model is based on the concept that a cell with hypothetically unlimited replicative potential—i.e. a ‘stem’ cell—can become ‘committed’ to a programme of limited replicative potential. This event is assumed to be stochastic and to have a fixed probability per stem cell division. the parameters of the model are: Pc, the probability of commitment; N, the number of differentiative divisions; and Tc, the cell-cycle times. By computer simulation, it is shown that Pc increases roughly exponentially at each successive stem cell division. According to the model, when the daughter of a stem cell becomes committed, its progeny proceed through N obligatory divisions before becoming terminally differentiated (post-mitotic). the best-fit value of N was found to be seven. The simulations also reveal that the absolute number of stem cells in the total population increases for most of the lifespan of the culture. When Pc becomes much greater than 0.5, the number of stem cells declines rapidly to zero, and the culture nears senescence. Sensitivity analysis shows that Pc can assume only a limited range of values at each stem-cell division.
Simulation of oxygen movement to plant roots as affected by tillage width and depth

Abstract The objective of this work was to determine, by electrical analog, how oxygen movement to plant roots is affected by two variables, i.e. width of tillage (amount of soil surface that is not sealed to the flow of oxygen) and depth of tillage. The electrical analog was developed for a row crop that had varying amounts of cultivated soil between the rows of plants. Rows were 51 cm apart. The amount of soil tilled between rows varied as follows: 12.5% (6 cm); 25% (13 cm); 50% (25 cm); 75% (38 cm); 100% (51 cm). The model assumed a maximum plow-layer depth of 20 cm. The amount of the plow layer tilled varied as follows: 33% (7 cm); 50% (10 cm); 67% (13 cm); 83% (17 cm); 100% (20 cm). The results from the experiment were compared with theoretical values in the literature. Conductance of oxygen to the root zone was affected more by width than by depth of tillage. The largest increase in conductance occurred with the smallest slit in the soil (12.5% of the soil surface tilled). The depth of tillage had a small effect on oxygen movement to plant roots, but the effect increased as the amount of tilled soil surface became larger. There were few deviations between the experimental and theoretical values, which suggested that the model was simulating expected values of conductance. The results showed that in order to increase oxygen movement to plant roots, it may be more important to till widely (extensively) than deeply.
Mitochondrial DNAs of Suillus: three fold size change in molecules that share a common gene order

We constructed restriction-site and gene maps for mitochondrial DNAs from seven isolates of five species of Suillus (Boletaceae, Basidiomycotina). Each mitochondrial genome exists as a single circular chromosome, ranging in size from 36 to 121 kb. Comparisons within species and between two closely related species revealed that insertions and deletions are the major form of genome change, whereas most restriction sites are conserved. Among more distantly related species, size and restriction-site differences were too great to allow precise alignments of maps, but small clusters of putatively homologous restriction sites were found. Two mitochondrial gene orders exist in the five species. These orders differ only by the relative positions of the genes for ATPase subunit 9 and the small ribosomal RNA and are interconvertible by a single transposition. One of the two gene arrangements is shared by four species whose mitochondrial DNAs span the entire size range of 36 to 121 kb. The conservation of gene order in molecules that vary over three-fold in size and share few restriction sites demonstrates a low frequency of rearrangements relative to insertions, deletions, and base substitutions.
Determination of surface-bound 228 Th and 226 Ra on hardware associated with neutral current detector deployment at the Sudbury Neutrino Observatory

A sensitive system for the determination of surface-bound thorium and uranium on detector components and deployment hardware associated with the Sudbury Neutrino Observatory is described. The method involves assay for 224 Ra and 226 Ra in ultra-pure water used to leach the component under test.
Sirolimus-induced hyperlipidaemia in liver transplant recipients is not dose-dependent.

Summary Background : Sirolimus is a potent immunosuppressive medication that acts by inhibiting T-cell proliferation. It has been used in kidney transplantation because of its lack of nephrotoxicity. It is now being investigated in liver transplantation, but there are concerns about safety and long-term side effects such as dyslipidaemia. Hypertriglyceridaemia is a common adverse event seen with sirolimus use, and often does not respond to dose reduction or anti-lipemic drugs. Method : We report six patients who have developed significant hyperlipidaemia while receiving sirolimus, in spite of therapeutic trough levels. Conclusion : All six patients showed either resolution or improvement in lipid levels with discontinuation of sirolimus.
Depression of Adrenal Corticosterone Production in Oophorectomized Rats

Corticosterone production by adrenal homogenates from oophorectomized rats does not differ from that of intact rats after 0-10 min of incubation in vitro but is significantly lower after 20-60 min of incubation. Supplementation with additional quantities of NADP and glucose-6-phosphate or NADPH alone after 10- and 30-min incubation does not alter the impairment of adrenal corticosterone production observed after oophorectomy. Prefreezing of adrenal homogenates stimulates corticosterone production, but the amount of corticosterone produced in prefrozen preparations from oophorectomized rats is lower than in prefrozen control homogenates. Preincubation of adrenal slices followed by homogenization likewise stimulates corticosterone production, but, in addition, the impairment caused by oophorectomy disappears. Corticosterone production in adrenal homogenates from oophorectomized rats progressively decreases (per 100 mg adrenal) as tissue concentration is increased. A homogenate mixture consisting of equal pa...
Scholarly African American Studies Journals

The field of African American studies overlaps with many areas in the social sciences and humanities, including education, history, labor and employment, marriage and family studies, political scie...
Asymptotic analysis of the ruin with stationary stable steps generated by dissipative flows

We study the exceedance probability of a high threshold (ruin probability) for a random walk with a negative linear drift, where the steps of the walk (claim sizes) constitute a stationary ergodic symmetric α-stable process. We casually use the language of insurance, although this is a popular problem in many other fields of applied probability as well. We refer to ergodic theory to split the step process into two independent processes. We focus on the processes generated by dissipative flows, which are known to have a mixed moving average representation, and we restrict our attention to regular moving averages with non-negative kernels. We give results for the order of magnitude of the exceedance probability as the threshold goes to infinity in the cases of discrete-time and continuous-time claim processes.
Aeronomy of CO2 Atmospheres: A Review

Abstract Data obtained by the UV spectrophotometer experiments and the radio occultation experiments on Mariners 6 and 7 indicate an atomic oxygen concentration of about 3% in the upper atmosphere, an exospheric temperature of about 350K, and a very low solar EUV heating efficiency for Mars. Laboratory studies do not support mechanisms for rapid recombination of CO and O in the upper atmosphere. Transport appears to control the O concentration. However, there is still a problem of accounting for CO-O2 recombination in the lower atmosphere. A satisfactory self-consistent explanation of all of the Mariner and Venera upper atmosphere data for Mars and Venus still has not been produced. Difficulties with the presently recommended low EUV solar fluxes and high Martian airglow brightness are discussed.
A new method of zone leveling for materials having distribution coefficients in the range of 0–0·6

Abstract By doping an originally pure crystal at both ends and by subsequently melting it repeatedly back and forth, the calculated impurity distributions, as obtained after each pass, converge to a horizontal straight line. This is, therefore, a useful method for obtaining a uniform impurity distribution along a single crystal. In the last zone, however, the abrupt change in impurity concentration, due to the normal freezing cannot be avoided. The first doping of the crystal has to be done before the first pass and the second doping at the other end of the crystal after the first pass. Graphs are given for different values of k , for the length of the crystal in relation to the zone length and for the minimum number of passes needed to obtain a uniform impurity distribution. The results indicate that the method is extremely well suited for materials with values of k up to 0·6, while ordinary zone leveling fails for materials with a value of k between 0·1 and 1. In the new method the impurity content in any pass is proportional to the introduced impurity content at one end. Thus any desired uniform impurity distribution can be easily obtained.
In situ holographic imaging of settling particles: applications for individual particle dynamics and oceanic flux measurements

A new dual-axis holographic imaging system provides a means for estimating in situ the sizes, shapes, settling rates and densities of both individual particles and aggregates. The optical system, which is an integral part of a free-drifting sediment trap (collection area = 0.66 m2), utilizes two independent imaging systems with HeNe laser illumination to record holographically the particles moving through the collection cup from two orthogonal perspectives. Mass accumulation is monitored in all cups by the upward-looking holographic imaging system and sequential imaging of particles using the horizontal system provides settling speed determinations. The configuration is flexible and can be programmed to collect as many as 500 far-field (Fraunhoffer) holographic records (250 for each axis). In addition, up to six sequential samples of particulate matter can be collected over periods ranging from as little as 3 h (30 min per sample) to as long as 6 days (1 day per sample). An isotonic high-viscosity medium (viscosity = 5.2 cp, density = 1.12 g ml−1) has been utilized in some sample cups to discrminate against organic material and to maximize the probability that large particles are slowed sufficiently to allow for sequential holographic imaging. Four free-drifting, holographically equipped sediment traps have been utilized on three cruises to the North Pacific Ocean where repeated deployments were made between 37 and 907 m. While analysis of the more than 4000 holograms is incomplete, the holographically determined dynamic densities for individual particles include high-density material of eolian origin (density ⋟ 2.6–5.2 g ml−1) and also lower density organic material (density ⋟ 1.2 – 2.21 g ml−1). Such optically enhanced sediment traps provide a means of directly recording particel settlin dynamics and may also provide insight into biological activity within sediment traps.
Acceptable ranges for vital signs during general anesthesia.

Objective. Define the ranges for normal vital signs during general anesthesia.Methods. We studied 50 patients undergoing general anesthesia. We asked residents to state desirable ranges for each patient's systolic and diastolic blood pressure (BP), heart rate (HR), SpO2, andPetCO2 during induction, intubation, maintenance, and emergence from anesthesia. We called these ranges the clinical operating range (COR) and observed the frequency, duration, and magnitude of transgressions of these CORs. We also recorded whether the transgressions were treated or tolerated, or whether the COR values were changed.Results. Upper COR values in the maintenance phase for systolic BP were 38%±20% above the preoperative values and 30%±20% above the values recorded just before induction of anesthesia. Lower COR values in the maintenance phase for systolic BP were 27%±9% below preoperative, and 31%±11% below pre-induction values. For HR, upper and lower COR values in the maintenance phase were 53%±44% above and 38%±17% below preinduction values, respectively. Transgressions of COR values for BP and HR were common, treatment frequent, and redefinition of COR values rare.Conclusion. Clinicians recognize ranges for vital signs during uneventful anesthesia. These CORs may differ from one stage of anesthesia to the next. Transgressions of these ranges are common. Not all transgressions are treated.
3D channel model extensions and characteristics study for future wireless systems

This work introduces a complete framework for three-dimensional (3D) channel extension based on two-dimensional (2D) channel models. In the 3D channel modeling, besides the azimuth angles, the multipath components of a receive-transmit pair are determined by elevation angles, correlations between elevation and azimuth, and the 3D configurations of a user equipment's (UE) location and velocity. The 3D channel characteristics for an active antenna system (AAS) are studied in terms of aggregated array gain and channel covariance matrix. The 3D channel model is generated and examined through Monte Carlo simulations and a comparison of fixed vertical beamforming and adaptive vertical beamforming is presented. The comparison shows that adaptive vertical beamforming can potentially provide up to 8dB improvement in coupling loss. In addition, it is shown that for line-of-sight (LoS) the 3D channel covariance matrix can be decoupled into two independent covariance matrices with reduced sizes that effectively leads to reduced feedback overhead. For non-line-of-sight (NLoS), the correlation-based Kronecker model technique can be used to generate the 3D channel matrix with reduced complexity compared to the geometry-based technique.
Silenced voices: Social work and the oppression of conservative narratives

Abstract Using a semi‐structured telephone interview format, this qualitative study explored the narrative of conservative Christians (N = 12) in social work. Faith was found to be very important to the respondents and was perceived by them to influence their social work. The respondents were found to endorse all of the values of the profession as delineated in the NASW Code of Ethics, which they viewed as compatible with their own values. However, respondents overwhelmingly felt oppressed in the profession which, they held, abdicated the ethical mandates for religious diversity. The results, they believed, included not being understood, discrimination, unwarranted negative criticism, and failure of NASW to work to eliminate domination and oppression on their behalf. Finally, they were hesitant to promote the general welfare of society for fear of reprisals by other social workers. The dissonance between the profession's ethical mandates and its actual practice appears to engender a significant degree of ...
Developmental changes and molecular weight of immunoreactive glucocorticoid receptor protein in the ovine fetal hypothalamus and pituitary

Parturition in the sheep is initiated by increased activity of the hypothalamus-pituitary-adrenal (HPA) axis in the fetus. Late in gestation, ACTH secretion increases because of increased stimulation to the HPA axis and a decreased cortisol negative feedback inhibition of ACTH secretion. We hypothesized that this alteration in cortisol negative feedback efficacy might result from a decrease in glucocorticoid receptor (GR) protein in the hypothalamus or pituitary. Fetal hypothalami and pituitaries were collected from healthy animals (74 days gestation to 4 weeks postnatally) and analyzed by Western blot for immunoreactive GR (iGR) protein. We detected two forms of iGR: a form consistent in molecular weight with the GR, and a form which is approximately half the size of the full-length receptor. We were not able to detect a developmental change in the intensity of immuno-staining for the full-length receptor protein in these tissues. However, the proportion of half-length relative to full-length GR increased significantly with developmental age. Exogenous estrogen, androgen, or tamoxifen treatment did not significantly affect the expression of GR protein. In conclusion, we detected a 97 kD iGR protein corresponding to the full-length receptor and a 45 kD iGR protein, or half-length receptor. The proportion of this half-length receptor protein relative to the full-length receptor increased significantly with development.
Damage to solid-state photodiodes by vacuum ultraviolet radiation

Abstract We report experimental results on the stability of photodiodes obtained at three different wavelengths in the vacuum ultraviolet spectral region. Two of these experiments were based on radiation damage inflicted with excimer lasers at 193 and 157 nm and one of them used 135 nm synchrotron radiation. It was found that the detector degradation rate increased considerably with the photon energy and depended on the structure of the photodiodes. Detectors based on the Si/SiO 2 interface were damaged much faster than Schottky-type diodes or Si diodes with metal passivating layers. Possible damage mechanisms to the Si/SiO 2 interface and its electronic structure are reviewed. In the end, a model to quantify the dependence of the damage on the photon energy is introduced.