cssi/SciSciGPT-SciSciNet huggingface dataset:
The impact of job mobility on earnings: using occupational and industrial classifications to identify job changes

According to the Bureau of Labor Statistics, the median number of years that a US worker has been with their current employer is 4.4 years. Although many job changes may not be classified as ‘career changes,’ any type of job change may have an impact on a person’s future earnings. In the present study, the following three types of job changes are examined in order to determine which ones result in higher incomes: a change in occupational status; a change in industry; or a change in both. Using data from the National Longitudinal Survey of Youth (NLSY), a log-linear wage regression with a correction for self-selection is estimated. Results suggest that changing jobs within the same industry or within the same occupation both increase a person’s income. However, a job change that is characterized by both a change in industry and occupation reduces a person’s income. The present study is one of the few studies to examine the effects of job mobility on earnings when mobility is defined in the context of chang...
Nonlinear Longitudinal Trajectories of Cholesterol and Neuropsychological Function

OBJECTIVE Prior literature has identified inconsistent longitudinal associations between total cholesterol and cognitive decline. The authors examined prospective nonlinear relations of coincident trajectories of total cholesterol and cognitive function among persons free of stroke, dementia, and other neurological disease. METHOD Up to 1,601 participants from the Baltimore Longitudinal Study of Aging (aged 19-93, 51% male, 75% White) underwent fasting cholesterol measurement and neuropsychological assessment on up to 12 occasions (M = 3.2, SD = 2.1) over up to 19 years (M = 6.4, SD = 5.3) of follow-up. Mixed-effects regression analyses were adjusted for age, sex, race, education, systolic blood pressure, body mass index, cardiovascular disease, lipid-lowering medication use, smoking, alcohol use, and depressive symptoms. RESULTS Analyses revealed significant longitudinal associations between quadratic total cholesterol and performance on measures of global mental status, verbal learning, executive function, and language (all ps < .05). In general, higher total cholesterol was associated with poorer middle-aged or young-old (60-69 years) cognitive performance, but better old-old (80-89 years) cognitive performance. Linear models also revealed an association between lower total cholesterol and accelerated decline in visual memory performance. CONCLUSIONS Overall, results indicate nonlinear longitudinal relations of total cholesterol to cognitive decline. Whereas higher cholesterol levels were associated with cognitive decline in the middle-aged or young-old, lower cholesterol levels were related to cognitive decline among old-old participants.
Action of nicotine on identified cells of the snail brain.

Evidence is presented to show that nicotine causes desensitization of certain cells of the snail brain. On cholinoceptive cells where the action of nicotine was excitatory (D-cells), nicotine (10−6 to 10−5 M) caused a dose-dependent depolarization and a decrease in input resistance. Firing rate was increased in pacemaker cells. On cholinoceptive cells where the action of nicotine was inhibitory (H-cells), nicotine (10−6 to 10−5 M) caused a dose-dependent hyperpolarization and a decrease in input resistance. Firing rate was decreased in pacemaker cells.
Estimating cell concentration in the presence of suspended solids: A light scatter technique

A novel sensor was developed, based on light scatter, to estimate the cell concentration in the presence of suspended solids. The light scatter properties of cells in the presence of suspended solids were investigated. Two crucial observations were made: first, that the light scatter from cells is essentially a linear function of cell concentration and, second, that invariant regions are present in the light scatter spectrum of cell/solid substrate mixtures. Invariant regions are wavelength intervals of the light scatter spectrum in which the light scatter reading is independent of solid substrate concentration and only a function of cell concentration. The occurrence of invariant regions is the key behavior which allowed the quantification of cell concentration in the presence of suspended solids. An algorithm was developed for the estimation, from light scatter data, of cell concentration in the presence of solid substrate. The light scatter approach was validated by comparing cell concentrations estimated by this technique to those obtained from DNA and carbon dioxide evolution rate measurements during a series of fermentations. The model system used was Bacillus subtilis var sakainensis ATCC 21394 growing on fishmeal as the sole nitrogen source. A model was developed based on the interactions of scatter and absorbance. This model reflects the hypothesis that invariant regions are caused by changes in the absorbance of the solid substrate as a function of wavelength. © 1992 John Wiley & Sons, Inc.
AUDIENCE MOTIVATION EFFECTS More Evidence

Survey data are applied to test the assertion that audience motivation for attending to political advertising influences the processing and effects of the advertising. The survey study attempts to supplement evidence supporting the assertion obtained using experimental methods. The study assesses the influence of two audience motivations—to learn candidates' stands on issues (issue) and to learn the personal qualities of the candidates (image)—on issue knowledge gain, recall of image information from political commercials, and recall of information from the video portion of political commercials. The mediating influence of intense processing of the commercials is also explored.
Purification and Characterization of Human Chorionic Gonadotropin

A purified preparation of human chorionic gonadotropin has been obtained by techniques of alcohol precipitation, ion exchange chromatography and gel filtration. Evidence is presented that the product is homogeneous in size and amino acid composition, but heterogeneous in electrical charge and sialic acid content. The polypeptide portion of the molecule has a high proline content (12.6 moles/mole of HCG) and appears to be composed of 2 identical subunits, each with a molecular weight in the range of 25,000 to 28,000. The biological activity of the purified material is in the range of 13,700 to 18,600 IU/mg. (Endocrinology 84: 298, 1969)
Processing mechanics for flip-chip assemblies

Abstract In this paper, a non-linear finite element framework has been implemented to simulate the sequential build-up of a flip-chip package. A generalized deformation model with element removal and addition is used to activate and deactivate the underfill material layer to simulate flip-chip package fabrication. Using process models, one can determine the warpage stresses at any intermediate stage in the process. In addition, topological change is also considered in order to model the sequential steps during the flip-chip assembly. Geometric and material nonlinearity which includes the creep behavior of underfill and solder balls, and temperature-dependent material properties are considered. Different stress-free temperatures for different elements in the same model are used to simulate practical manufacturing process-induced thermal residual stress field in the chip assembly. This approach (the processing model established in this paper) is in contrast to the non-processing model employed by many researchers, which is shown to yield overly conservative and sometimes erroneous results, leading to non-optimal design solutions. From the finite element analysis, it is found that the strains and deflections obtained from the non-processing model are generally smaller than those obtained from the processing model due to the negligence of the bonding process-induced residual strains and warpage. Furthermore, the fatigue life for the outmost solder ball predicted by the processing model is much shorter than that predicted by the non processing model based on the Coffin–Manson equation. On the other hand, in order to prove the soundness of the framework established in this paper, the test results obtained by using the laser moireinterferometry technique are compared with the results achieved from the proposed numerical analysis vehicle. It is shown that the deformation values of the flip-chip package predicted from the finite element analysis are in a good agreement with those obtained from the test.
Coupled Cluster and Second-Order Møller−Plesset Perturbation Studies of the Mechanism of the Gas-Phase Atom−Radical Reaction of Atomic Hydrogen with CF2 Radical

The mechanism for the reaction of CF2 radicals with H atoms has been examined using coupled cluster theory. There are two competing pathways for the formation of the products CF + HF. The first pathway involves direct abstraction of fluorine from CF2 by H atoms, the barrier for which is 46.5 kcal mol-1. The second pathway involves the addition of H atoms to CF2 to form CF2H, followed by a three-center elimination of HF. The overall barrier for these two steps is 10.0 kcal mol-1.
Variables Affecting the Decision to Withdraw from Liberal Arts and Science Courses.

Existing research on why college students withdraw from individual courses has been mostly descriptive. The author reports the results of research designed to identify variables that place students at risk of withdrawing from specific courses. Self-reported data that included categorical and continuous variables were collected over two semesters from community college students enrolled in representative liberal arts and science courses at Illinois Central College. A logit analysis revealed that high levels of classroom attendance and attentiveness increased a student's odds of remaining in the class. Parents' education levels also were found to be significant predictors of students' decisions to remain in a course. Gender, age, and class GPA, however, were not significant predictors.
Building Understanding of Municipal Service Integration: A Comparative Case Study of NYC311 and Philly311

A 311 system provides quick and easy access to non-emergency municipal services and information through a consolidated channel. This study explores the operation of 311 contact centers in New York and Philadelphia and identifies critical success factors and challenges of municipal service integration. Having the right technology at the right time is identified as a critical technological factor. While the lack of technical interoperability between a 311 system and departmental legacy systems is a major barrier to connecting a variety of systems, human agents fill the middle ground so that training for qualified agents is crucial for their role. Inter-agency coordination and collaboration is pivotal to creating and updating service level agreements and knowledgebase. However, turf protection raises cross-organizational concerns. The executive support and political champions help resolve interdepartmental conflicts.
Selecting for Memory? The Influence of Selective Attention on the Mnemonic Binding of Contextual Information

Not all of what is experienced is remembered later. Behavioral evidence suggests that the manner in which an event is processed influences which aspects of the event will later be remembered. The present experiment investigated the neural correlates of "selective encoding," or the mechanisms that support the encoding of some elements of an event in preference to others. Event-related MRI data were acquired while volunteers selectively attended to one of two different contextual features of study items (color or location). A surprise memory test for the items and both contextual features was subsequently administered to determine the influence of selective attention on the neural correlates of contextual encoding. Activity in several cortical regions indexed later memory success selectively for color or location information, and this encoding-related activity was enhanced by selective attention to the relevant feature. Critically, a region in the hippocampus responded selectively to attended source information (whether color or location), demonstrating encoding-related activity for attended but not for nonattended source features. Together, the findings suggest that selective attention modulates the magnitude of activity in cortical regions engaged by different aspects of an event, and hippocampal encoding mechanisms seem to be sensitive to this modulation. Thus, the information that is encoded into a memory representation is biased by selective attention, and this bias is mediated by cortical-hippocampal interactions.
Stability conditions for a pipeline polling scheme in satellite communications

This paper considers the unknown stability conditions of a pipeline polling scheme proposed for satellite communications. This scheme is modelled as a cyclic-service system with limited service and reservation. The walk times and the maximum number of services to be performed during each polling are dependent on the queue lengths of the stations. The main result is the derivation of the necessary and sufficient stability conditions of the system. Our approach is to map the multi-dimensional stability problem into many 1-dimensional stability problems through the concept of the least stable queue. The least stable queue is one that will become unstablefirst when the system load increases in some parameter region. The stability of the least stable queue thus implies stability of the system. The stability region for the whole system is then the union of the queue stability regions of all the least stable queues that are obtained through dominant systems and Loynes' theorem. We also propose a computable sufficient condition that is tighter than the existing result and present some numerical results.
Steroid Use among Miami's Public School Students, 1992: Alternative Subcultures: Religion and Music versus Peers and the “Body Cult”

This analysis examined self-reported use of steroids by 478 adolescents in Dade County, Florida public schools during 1992. Statistically significant factors which tended to increase the probability of steroid use by adolescents included peer use of steroids, being male, and residing either with their mothers or on their own. The only statistically significant variables which are negatively related to steroid use are that religion is an important part of their lives and that students are involved in musical activities at school.
Longitudinal patterns of gambling activities and associated risk factors in college students

Aims To investigate which clusters of gambling activities exist within a longitudinal study of college health, how membership in gambling clusters change over time and whether particular clusters of gambling are associated with unhealthy risk behaviour. Design Four-year longitudinal study (2002–2006). Setting Large, public university. Participants Undergraduate college students. Measurements Ten common gambling activities were measured during 4 consecutive college years (years 1–4). Clusters of gambling activities were examined using latent class analyses. Relations between gambling clusters and gender, Greek membership, alcohol use, drug use, personality indicators of behavioural undercontrol and psychological distress were examined. Findings Four latent gambling classes were identified: (1) a low-gambling class, (2) a card gambling class, (3) a casino/slots gambling class and (4) an extensive gambling class. Over the first college years a high probability of transitioning from the low-gambling class and the card gambling class into the casino/slots gambling class was present. Membership in the card, casino/slots and extensive gambling classes were associated with higher scores on alcohol/drug use, novelty seeking and self-identified gambling problems compared to the low-gambling class. The extensive gambling class scored higher than the other gambling classes on risk factors. Conclusions Extensive gamblers and card gamblers are at higher risk for problem gambling and other risky health behaviours. Prospective examinations of class membership suggested that being in the extensive and the low gambling classes was highly stable across the 4 years of college.
Topographic organization of sensory projections to the olfactory bulb

The detection of odorant receptor mRNAs within the axon terminals of sensory neurons has permitted us to ask whether neurons expressing a given receptor project their axons to common glomeruli within the olfactory bulb. In situ hybridization with five different receptor probes demonstrates that axons from neurons expressing a given receptor converge on one, or at most, a few glomeruli within the olfactory bulb. Moreover, the position of specific glomeruli is bilaterally symmetric and is constant in different individuals within a species. These data support a model in which exposure to a given odorant may result in the stimulation of a spatially restricted set of glomeruli, such that the individual odorants would be associated with specific topographic patterns of activity within the olfactory bulb.
Adjuvant and immunogenic properties of bacterial lipopolysaccharide in ige and igg1 antibody formation in mice.

Abstract The ability of Gram-negative lipopolysaccharide (LPS) to function as an adjuvant and as an antigen in IgE and IgG 1 immune responses in mice was investigated. LPS failed to induce LPS-specific IgE or IgG 1 under a variety of experimental conditions. Both isolated LPS and whole heat-killed bacteria were capable of enhancing IgE and IgG 1 antibody formation to a protein antigen, egg albumin (EA). The LPS-induced anti-EA, IgE, and IgG 1 antibody titers exhibited a cycling phenomenon with time. In the presence of LPS, IgE, and IgG 1 antibodies specific for EA did not occur in athymic nude (BALB/c-nu/nu) mice, demonstrating the inability of LPS to substitute for the stringent requirement for T cells in homocytotropic antibody formation.
Counterterrorism And Its Impact On Terror Support And Recruitment: Accounting For Backlash

This article presents a dynamic model in which counterterrorism policies have the potential to generate positive public support for terrorism via a backlash that may fuel terror recruitment. For an optimizing government aiming at maximizing security, this phenomenon produces a natural bound on proactive counterterror policy that is related to the dynamic path of conflict. Moreover, terror is a persistent phenomenon that requires patience on the part of the target government for optimal counterterror policies to be realized. Finally, the potential for backlash yields insights into the need for target governments to fight an information war to change public opinion regarding its own policies and the ultimate effect of terror attacks.
Cocaine modulates mu-opioid receptor mRNA but not c-fos mRNA levels in primary cortical astrocytes.

Abstract Cocaine is known to modulate the opioid system in several brain regions, including the cortex. Glial cells that are derived from the neonatal cortex have been shown to express opioid peptides and opioid receptors. In this study we investigated the effects of cocaine on c- fos and mu-opioid receptor mRNA levels in primary cortical astrocyte cultures, using RT-PCR and quantitative solution hybridization assays. Astrocyte cultures from 1-day-old Fischer rats were untreated or treated with cocaine for 30 min, 2 h, or 5 h. While c- fos mRNA levels did not change at any time, mu-opioid receptor mRNA levels decreased by 75% after 2 and 5 h of cocaine treatments. Our data suggest that cocaine differentially modulates c- fos and opioid signaling in astrocyte cell culture.
Energetics of the reactions of FCO with O2 using unrestricted Møller-Plesset perturbation theory with spin annihilation

Abstract The reactions of fluoroformyl radicals FCO with O 2 have been studied with ab initio molecular orbital methods. Reactants, transition structures and products were optimized at UHF/6-31G* and UMP2/6-31 G* levels of theory. The barrier heights have been computed by using unrestricted Hartree-Fock and Moller-Plesset perturbation theory up to fourth order, including single, double, and quadruple excitations. Spin contamination in the UHF wavefunction has been reduced by annihilating the largest spin contaminant. A small barrier is found for addition of O 2 to FCO to yield the FC(O)O 2 radical, and annihilation of the largest spin contaminant lowers the barrier for this reaction. The extraction of fluorine from FCO by O 2 to yield FO 2 and CO is endothermic with no additional barrier.
Noninformative priors and frequentist risks of bayesian estimators of vector-autoregressive models

In this study, we examine posterior properties and frequentist risks of Bayesian estimators based on several noninformative priors in vector autoregressive (VAR) models. We prove existence of the posterior distributions and posterior moments under a general class of priors. Using a variety of priors in this class we conduct numerical simulations of posteriors. We find that in most examples Bayesian estimators with a shrinkage prior on the VAR coefficients and the reference prior of Yang and Berger (Ann. Statist. 22 (1994) 1195) on the VAR covariance matrix dominate MLE, Bayesian estimators with the diffuse prior, and Bayesian estimators with the prior used in RATS. We also examine the informative Minnesota prior and find that its performance depends on the nature of the data sample and on the tightness of the Minnesota prior. A tightly set Minnesota prior is better when the data generating processes are similar to random walks, but the shrinkage prior or constant prior can be better otherwise.
Serum Progesterone Levels in Ovariectomized Rats Injected with Progesterone and Estrone: Relation to Pregnancy Maintenance and Growth of Decidual Tissue1

Serum progesterone levels (ng/ml) were measured by competitive protein binding in ovariectomized pregnant or pseudopregnant rats with or without deciduomata, treated daily with 2 or 4 mg progesterone, with (E/P2 or E/P4) or without (P2 or P4) 1 Mg estrone. Treatment with E/P2 or E/P4 markedly enhanced fetal survival and deciduoma growth over the results obtained with P2 or P4, but serum progesterone levels were not different from those animals receiving progesterone alone. The serum progesterone concentrations were directly related to the dose of progesterone administered, were not significantly affected by duration of treatment, the presence of developing fetuses or decidual tissue, and were significantly lower than the values found in intact pregnant or pseudopregnant rats. These findings plus the lack of effect of pregnancy or deciduoma formation on the metabolic clearance rate of progesterone (Pepe and Rothchild, submitted with this paper) indicated that in the rat, changes in the level of progesteron...
Size, number, cellular proliferation, and atresia of gonadotropin-induced follicles in ewes.

To determine the effect of exogenous gonadotropin on size, number, cellular proliferation, and atresia of follicles, ewes (n = 3-5/treatment/day) received an injection of vehicle or FSH-P (a pituitary extract) twice daily on Days 13, 14, and 15 (5, 4, and 3 mg FSH-P/injection, respectively; Day 0 = estrus) and were slaughtered on Days 14, 15, or 16 (i.e., after 24, 48, or 72 h of FSH-P treatment, respectively). An additional group of ewes (Day 13 control) received no treatment and were slaughtered on Day 13. All ewes received an i.v. injection of bromodeoxyuridine (BrdU, a thymidine analog; 5 mg/kg-1 BW) 1 h before slaughter. For both ovaries from each ewe, number and surface diameter of all visible follicles were recorded, and antral follicles were classified as small ( 3 mm to 6 mm). To evaluate rate of proliferation of follicular cells, ovaries were fixed by perfusion with Carnoy's solution, and BrdU was immunolocalized in paraffin-embedded sections by use of a specific primary antibody and indirect immunoperoxidase detection. As an index of the rate of cellular proliferation, labeling index (LI: number of BrdU-labeled nuclei expressed as a percentage of total nuclei) of granulosa and thecal cells was determined by image analysis of antral follicles of known diameter. Follicular status (atretic vs. nonatretic) also was evaluated morphologically by using the histological sections. After 24 h of treatment (i.e., on Day 14), FSH-P-treated ewes had an increased (p < 0.01) number of medium follicles compared with vehicle-treated ewes.(ABSTRACT TRUNCATED AT 250 WORDS)
Interfacial Charge Carrier Dynamics of Colloidal Semiconductor Nanoparticles

Understanding the dynamic properties of charge carriers at the liquid−semiconductor interface is critical to many applications including photocatalysis, solar energy conversion and photoelectrochemistry. Dynamic properties of charge carriers, including trapping, recombination, and transfer, in a number of semiconductor nanoparticle systems have been studied using powerful time-resolved laser techniques. Several interesting features have been identified, including exciton−exciton annihilation upon trap state saturation at high excitation intensities for CdS, CdSe, TiO2, ultrafast electron injection in dye sensitization of TiO2, increased transient absorption over transient bleach with increasing intensity for Ag2S and CuxS due to trap state saturation, surface dependence of electronic relaxation in PbI2 and BiI3, complex kinetics of the orange emission in Mn-doped ZnS, and surface-independent relaxation for Fe2O3 and PbS. These observations provide new insight into the interfacial charge carrier properties...
Induction of mitogen-activated protein kinase signal transduction pathway during gastric ulcer healing in rats ☆ ☆☆ ★

Abstract Background & Aims: Previous studies have shown that gastric ulceration stimulates epithelial cell proliferation and overexpression of epidermal growth factor (EGF) and EGF receptor (EGF-R) in the mucosa bordering necrosis. The aim of this study was to investigate whether extracellular signal-regulated kinase (ERK) cascade is involved in the healing of experimental gastric ulcers. Methods: We studied EGF-R levels, EGF-R phosphorylation levels, and ERK1 and ERK2 activity in normal and ulcerated rat gastric mucosa. We also examined the effect of Tyrphostin A46 (potent inhibitor of EGF-R and EGF-R kinase–dependent proliferation) on the above parameters. Results: During the initial stages of healing (3 and 7 days), ulcerated mucosa showed significant increase (vs. controls) in protein tyrosine kinase activity, EGF-R levels (510% and 550%), EGF-R phosphorylation levels, ERK1 activity (430% and 880%), and ERK2 activity (550% and 990%). Tyrphostin A46 treatment significantly inhibited ulcer healing and reduced EGF-R levels, EGF-R phosphorylation, and ERK1 and ERK2 activity. Conclusions: These findings indicate that experimental gastric ulcer healing involves activation of EGF-R–ERK signal transduction pathway. GASTROENTEROLOGY 1998;114:706-713
Mechanisms of Cardiac Control in Exercise

Left ventricular performance during spontaneous exercise has been continuously analyzed in terms of direct recordings of diameter, effective pressure and other parameters derived by electronic computors. The changes in left ventricular performance during treadmill exercise have been compared with a number of experimentally induced responses in the same intact unanesthetized dog on the same day. These direct comparisons revealed that experimentally-induced increased venous return, reduced peripheral resistance, or administration of autonomic hormones do not reproduce the spontaneous exercise response. Better reproductions of the exercise response could be achieved by careful administration of isopropyl arterenol (Isuprel), by combined administration of epinephrine or norepinephrine) and experimental tachycardia or by stimulating sympathetic nerves to the heart. Stimulation of discrete areas in the diencephalon reproduced the exercise response with remarkable accuracy without movement or evidence of distress.
X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and principal component analysis of the hydrolysis, regeneration, and reactivity of N-hydroxysuccinimide-containing organic thin films

N-Hydroxysuccinimide (NHS) esters are widely used as leaving groups to activate covalent coupling of amine-containing biomolecules onto surfaces in academic and commercial surface immobilizations. Their intrinsic hydrolytic instability is well-known and remains a concern for maintaining stable, reactive surface chemistry, especially for reliable longer term storage. In this work, we use X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to investigate surface hydrolysis in NHS-bearing organic thin films. Principal component analysis (PCA) of both positive and negative ion TOF-SIMS data was used to correlate changes in the well-defined NHS ester oligo(ethylene glycol) (NHS-OEG) self-assembled monolayers to their surface treatment. From PCA results, multivariate peak intensity ratios were developed for monitoring NHS reactivity, thin-film thickness, and oxidation of the monolayers during surface hydrolysis. Aging in ambient air for up to 7 days resulted in hydroly...
Structural changes induced by osmotic water flow in rabbit proximal tubule.

When a transepithelial osmotic difference was imposed in perfused proximal straight tubules (270 mOsm/kg H2O in the lumen and 290 in the bath) in the absence of bath colloid, a severe vacuolation (appearance of lucent spaces) developed within the epithelium such that view of the lumen border was obscured within 5 +/- 1 min (N = 13 tubules at 23 degrees C). This vacuolation was less severe if the bath was hypotonic to the lumen or if the magnitude of the osmotic difference was reduced. If colloid (6% wt/vol of either bovine serum albumin or 70,000 molecular wt dextran) was included in the bathing medium, vacuolation was either not observed or was minimal, but became severe upon removal of the colloid and obscured the lumen within 6 +/- 1 min (N = 8 for albumin and N = 4 for dextran at 23 degrees C). At 38 degrees C, vacuolation obscured the lumen within 4 +/- 1 min following the removal of albumin (N = 5). ANOVA suggests that none of the times for vacuolation to occur differed. The rate of passive volume flow due to the osmotic difference was unaffected by vacuolation (0.9 +/- 0.1 nl.min-1.mm-1 with albumin to 0.8 +/- 0.1 without albumin and vacuolated, N = 8 at 23 degrees C, P greater than 0.2 using a paired t-test). Electron microscopic examination of tubules fixed after vacuolation showed lucent spaces within the cytoplasm. These results suggest that the presence of serosal colloid protected the epithelial cells from injury during rapid transepithelial water flow. The mechanism for this protective effect is not apparent, but may be related to effects of colloid in maintaining normal volume absorption in the proximal nephron.
Variation of Superoxide Dismutase in Bovine Milk

Abstract Individual cow milk is highly variable in its resistance to oxidation. Variation in the enzyme (superoxide dismutase) concentration may have a minor effect on the oxidative stability of individual cow's milk. Milk from 11 Holsteins and 11 Jerseys were analyzed for 17 wk for superoxide dismutase, xanthine oxidase, oxidized lipids as determined by thiobarbituric acid values, milk produced, and fat content. All cows were of good health and on normal feed but varied in stage of lactation and age. Average superoxide dismutase concentration was 1.1±.48 units/ml with a range of .06 to 2.88 units/ml and a variance of .23. Concentration of superoxide dismutase in milk was approximately 10 2 lower than in bovine blood. Assay of individual cow milk indicated no significant difference in superoxide dismutase concentration between night and morning milkings. Also, superoxide dismutase concentration was affected by breed but not by stage of lactation or age. Superoxide dismutase decreased the minor pro-oxidant effect of xanthine oxidase. However, the concentration of superoxide dismutase in individual cow milk did not account for the large variability in oxidative resistance in raw milk that had not been exposed to light.
Synthesis and characterization of a carbon suboxide complex of nickel, (PPh3)2Ni(C,C':.eta.2-C3O2)

Carbon suboxide reacts with (PPh 3 ) 2 Ni(C 8 H 12 ) in cold Et 2 O to afford (PPh 3 ) 2 Ni(C,C':η 2 -C 3 O 2 ) (1) as a yellow-green precipitate in 85% yield. Although 1 decomposes to nickel carbonyl products on dissolution in hydrocarbon solvents, it has been characterized by solid-state IR and multinuclear ( 13 C, 31 P) CP-MAS solid-state NMR spectroscopic techniques
Elevated rate of DNA synthesis and its correlation to cAMP-phosphodiesterase activity during induction of polydactyly in mouse embryos heterozygous for Hemimelia-extra toe (Hmx)

The induction of polydactyly in mouse embryos heterozygous for Hemimelia-extra toe (Hmx) is associated with aberrant outgrowth of the developing autopod on day 12 of gestation. We have quantitated the rate of DNA synthesis and the activity of cAMP-phosphodiesterase (PDE) that is characteristic of the prospective polydactylous region. Mid-stage 18 hind-limb buds were labeled with [3H]dThd either in situ using whole embryo culture, or as isolated preaxial autopod fragments cultured on a membrane substratum. The mean specific activities of incorporation were compared for normal (+/+) and mutant (Hmx/+) genotypes. A significant (P less than or equal to 0.01) 19% increase, peculiar to the prospective polydactylous region, was measured after 4 hours in embryo culture. The same increment was detected after 4 hours in organ culture, but was amplified linearly to 55% when incubation was extended to 20 hours. During this period, continuous exposure to 1.0 mM IBMX (3-isobutyl-1-methyl xanthine), an inhibitor of cAMP-PDE activity, "slowed down" the rate of DNA synthesis to untreated +/+ proportions. When cAMP-PDE activity was assayed in uncultured autopods, a significant (P less than or equal to 0.01) 18% increase was detected within the prospective polydactylous region specifically on stage 18 of gestation. This is the developmental phase during which polydactylous outgrowth is induced in situ. Thus, uncontrolled cAMP-PDE activity may, in part, provoke the enhanced rate of cell proliferation.
Representations of Clinical Reasoning in PBL Meetings: The Inquiry Trace

Background: Barrows has recommended that a particular approach to inquiry be utilized within Problem‐Based Learning (PBL). Purpose: We describe an observational technique designed to document the inquiry and theorizing activities of a PBL team working through a clinical problem. Methods: The Inquiry Trace is an analytic instrument that represents PBL group talk and captures the temporal quality of the clinical reasoning process. It consists of a list of diagnostic theories advanced by the group juxtaposed with the accumulating body of evidence pertaining to the case. Results: The resulting matrix is augmented with annotations describing other significant events that occur (e.g., the generation of a learning issue). Conclusions: Although what is recorded on the Inquiry Trace is not reasoning itself, it provides a temporal record of a sequence of observable events that mark the group's reasoning with respect to a case. It serves as a useful abstraction, therefore, for studying and understanding the reasonin...
Including Frequent Emergency Department Users With Severe Alcohol Use Disorders in Research: Assessing Capacity

Study objective Frequent emergency department (ED) users with severe alcohol use disorders are often excluded from research, in part because assessing capacity to provide consent is challenging. We aim to assess the feasibility of using the University of California, San Diego Brief Assessment of Capacity to Consent, a 5-minute, easy-to-use, validated instrument, to screen for capacity to consent for research in frequent ED users with severe alcohol use disorders. Methods We prospectively enrolled a convenience sample of 20 adults to assess their capacity to provide consent for participation in 30-minute mixed-methods interviews using the 10-question University of California, San Diego Brief Assessment of Capacity to Consent. Participants were identified through an administrative database, had greater than 4 annual ED visits for 2 years, and had severe alcohol use disorders. The study was conducted with institutional review board approval from March to July 2013 in an urban, public, university ED receiving approximately 120,000 visits per year. Blood alcohol concentration and demographic data were extracted from the medical record. Results We completed assessments for 19 of 20 participants. One was removed because of agitation. Sixteen of 19 participants passed each question and were deemed capable of providing informed consent. Interventions to improve understanding (prompting and material review) were required for 15 of 19 participants. The mean duration to describe the study and perform the assessment was 10.4 minutes (SD 3 minutes). The mean blood alcohol concentration was 211.5 mg/dL (SD 137.4 mg/dL). The 3 patients unable to demonstrate capacity had blood alcohol concentrations of 226 and 348 mg/dL, with 1 not obtained. Conclusion This pilot study supports the feasibility of using the University of California, San Diego Brief Assessment of Capacity to Consent to assess capacity of frequent ED users with severe alcohol use disorders to participate in research. Blood alcohol concentration was not correlated with capacity.
The recovery functions of auditory event-related potentials during split-second discriminations ☆

We examined the recovery cycles of auditory event-related potentials (ERPs) in a high-speed auditory discrimination task and in passive conditions. Each trial contained 3 tones cued by a warning flash. In passive conditions, auditory ERPs consisted mainly of N1 (108 msec) and P2 (213 msec) components superimposed on a small CNV. The N1 and P2 were comparable in amplitude and both had prolonged refractory periods. In discriminative reaction time (DRT) conditions the same tones cued or inhibited press responses and elicited additional endogenous components (principally the Nd and P3). ERPs in DRT conditions were superimposed upon a prominent CNV that began after the warning cue and lasted throughout the signal delivery period. The N1 was larger in active than passive conditions and showed less marked refractory effects, while the P2 was smaller and showed more marked refractoriness. Differences between active and passive conditions could be explained by the presence of an endogenous negative potential (the Nd) with a short refractory period that was superimposed upon the N1 and P2. The P3 was recorded only in active conditions. At short ISIs (0.5 sec), P3 amplitudes were reduced and P3 latencies lengthened in parallel with prolongations in reaction time due to so-called psychological refractory period (PRP) effects. Both P3 recovery and the PRP reflected central mechanisms since they were observed at short ISIs when stimuli cueing different responses succeeded one another. N1 and P3 amplitudes diminished over the course of the experiment in both active and passive conditions. The decrease (amounting to about 30% of initial amplitudes) did not appear due to reductions in vigilance, since it was not accompanied by changes in reaction time or response accuracy, or by changes in other endogenous components (CNV or Nd). Short-term N1 habituation was unaffected by long-term amplitude reductions suggesting that independent mechanisms were responsible for the two phenomena.
Intraabdominal abscess rate after laparoscopic appendectomy.

Abstract Background: Studies suggest increased intraabdominal abscess (IA) rates following laparoscopic appendectomy (LA), especially for perforated appendicitis. Consequently, an open approach has been advocated. The aim of our study is to compare IA rates following LA performed by a laparoscopic surgery and a general surgical service within the same institution. Methods: Data of LA patients treated at Los Angeles County-University of Southern California (LAC-USC) Medical Center between March 1992 and June 1997 were reviewed. The main outcome measure was postoperative IA. Results: In all, 645 LA were reviewed. A total of 413 LA (285 acute, 61 gangrenous, 67 perforated appendicitis) were performed by three general surgical services (10 attendings). Ten abscesses occurred postoperatively (2.4%), 6 with perforated appendicitis. After the laparoscopic service was introduced, 232 standardized LA (126 acute, 46 gangrenous, 60 perforated) were performed by two attendings. One IA occurred (gangrenous appendicitis). The IA rate for perforated appendicitis was significantly lower on the laparoscopic service ( P = 0.025). There was no difference in IA rates for acute and gangrenous appendicitis. There was no mortality in either group. Conclusion: IA rate following LA for perforated appendicitis was significantly reduced on the laparoscopic service. Mastery of the learning curve and addition of specific surgical techniques explained this improved result. Therefore, laparoscopic appendectomy for complicated appendicitis may not be contraindicated, even for perforated appendicitis.
Ramanujan's ternary quadratic form

do not seem to obey any simple law.” Following I. Kaplansky, we call a non-negative integer N eligible for a ternary form f(x, y, z) if there are no congruence conditions prohibiting f from representing N. By the classical theory of quadratic forms, it is well known that any given genus of positive definite ternary quadratic forms represents every eligible integer. Consequently if a genus consists of a single class with representative f(x, y, z), then f represents every eligible integer. In the case of Ramanujan’s form, this only implies that an eligible integer, one not of the form 4(16μ+ 6), is represented by φ1 or φ2.
Local environment of transition metal ternary dopants in β phase transition metal aluminides

Abstract We have utilized the technique of EXAFS to investigate the local environment of Fe and Mo in Fe02Co50Al48 and in Mo02Ni50Al48 respectively. We find that Co atoms drive competing Fe atoms to the “Al type” sites, whereas Mo precipitates as small particles of BCC Mo. Our results are of possible significance in relation to findings by others of ductility enhancement in ternary doped β phase NiAl.
Chiral ligand optimization in the asymmetric zirconium-zinc transmetalation aldehyde addition reaction.

The in situ hydrozirconation–transmetalation-aldehyde addition process is a convenient method for the generation of allylic alcohols. Ongoing research has focused on enhancing the enantioselectivity and substrate scope of this process. A chiral β-amino thiol scaffold was evaluated in the addition reaction. Amino thiols tend to provide the highest ee's, in part due to the higher affinity of sulfur for zinc over zirconium. A class of valine-based thiol ligands was identified to be effective for the formation of enantiomerically enriched allylic alcohols in terms of low ligand loading and high % ee. Chirality, 2008. © 2007 Wiley-Liss, Inc.
An exploration of a continuum method for the solvation of biomolecules that includes solute polarisation

Abstract A method based on the continuum solvation model of Miertus and Tomasi (S. Miertus and J. Tomasi, Chem., Phys., 65 (1982) 239), which can be used to calculate the free energy change in transferring a molecule from the gas phase to a solvent, is presented. The solute is represented as a set of interlocking spheres with a polarisable point charge at each center. In order to reduce the number of atom types in the method, the atoms are assigned to classes based on the concept of molecular orbital valency state as proposed by Clementi. Solute polarisation by the solvent field and the effects of cavitation are included. The parameterisation, based on the Frage potential, and the results of the calculations for a series of molecules ranging from H2O to small peptides are presented. Other applications include ionic solvation and the formation of “salt-bridges”, which are essential for the stabilisation of amino acid residues with charged side chains. Initial results from the incorporation of this algorithm in a conformational study on Met-enkaphlin (met is methionine) are also presented.
Current algebra description of double pion photoproduction

Abstract The reaction γ N → 2 π N is studied in the limit in which one pion is “soft”. The matrix element is shown to be dominated by the equal time commutator term, 〈Nπ|A μ |N〉, thus providing a new way to measure the latter matrix element. The dominant contribution is shown to coincide with the interaction current terms in the static model description of Cutkosky and Zachariasen, and hence to agree with experiment near the Δ (1238) + π threshold. Similar considerations hold for radiative scattering, π N → π N γ .
Corpus linguistics and the study of literature: Back to the future?

The present paper introduces corpus-based analytical techniques and surveys some of the specific ways in which corpus analysis has been applied to the study of literature. In recent years, those research efforts have been mostly carried out under the umbrella of ‘corpus stylistics’. Most of these studies focus on the distribution of words (analyzing keywords, extended lexical phrases, or collocations) to identify textual features that are especially characteristic of an author or particular text. Corpus-based grammatical and pragmatic analyses of literary language are also briefly considered. Then, in the concluding part of the paper, I briefly survey earlier computational and statistical research on authorship attribution and literary style. While that research tradition is in some ways the precursor to more recent work in corpus stylistics, it is also complementary to recent research in its application of sophisticated statistical and computational methods.
Cytochrome P450 side-chain cleavage (P450scc) in the hen ovary. II. P450scc messenger RNA, immunoreactive protein, and enzyme activity in developing granulosa cells.

Previous studies have indicated that developing avian granulosa cells collected from follicles 2-3 wk prior to ovulation (e.g. 6-8-mm in diameter) are steroidogenically incompetent, apparently due to a lack of functional cytochrome P450 side-chain cleavage (P450scc) enzyme activity. The present studies were designed to test this hypothesis by determining the absence or presence of P450scc messenger RNA, immunoreactive protein, and enzyme activity in granulosa tissue of developing hen ovarian follicles. Additionally, the interactive roles of FSH, the adenylyl cyclase-cAMP system, and the protein kinase C pathway in granulosa cell differentiation were investigated. Granulosa cells collected from developing, 6-8-mm follicles were found to contain extremely low but detectable levels of a single, 2.0-kb P450scc mRNA transcript, as well as immunoreactive P450scc protein (53 kDa). However, this protein was apparently incapable of converting 25-hydroxycholesterol to pregnenolone in a cell-free system. Preincubation of granulosa cells with ovine FSH or forskolin for 24 h rendered the cells capable of converting cholesterol precursor to pregnenolone during a subsequent 3-h incubation. Inclusion of the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), in the preincubation medium blocked the stimulatory actions of FSH and forskolin on the induction of P450scc activity; however, PMA-preincubation did not alter the ability of granulosa cells to convert exogenous pregnenolone to progesterone compared to vehicle-pretreated cells. These data suggest that steroidogenic incompetency in differentiating avian granulosa cells is primarily due to a lack of active P450scc enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)