cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of pretraining on subsequent cycloheximide induced amnesia.

Abstract In the first experiment, mice were trained on a passive avoidance (PA) task, given one extinction trial, and then were injected with cycloheximide or saline shortly before retraining on the PA task. On a subsequent test trial, the performance of the cycloheximide group was inferior to the saline group, but superior to a cycloheximide group not given the pretraining experience. In the second experiment, one group of mice was given cycloheximide before each of two training sessions while another group received cycloheximide before the first training session and saline before the second. The group given cycloheximide before each training session was amnesic for both sessions to an equal degree, while the other group was amnesic for only the first session. The final test performance of the latter group was similar to that of a saline group not given any pretraining experience. These data seem to indicate that pretraining has limited effect on subsequent cycloheximide induced amnesia, and that such amnesia is the result of impaired memory formation rather than impaired memory retrieval.
Target localization with a single-antenna monostatic radar via multipath exploitation

In urban sensing and through-the-wall radar, the existence of targets in proximity to walls or buildings results in multipath returns. In this paper, we exploit the multipath from the walls to achieve target localization with a single sensor. We deal with sparse scenes of single targets. A time-of-arrival wall association algorithm is derived to relate target multipath returns to the respective walls, followed by a nonlinear least squares optimization to determine the target location. Simulated and experimental data are used to validate the proposed algorithms.
Group paired-associate learning: A safeguard against E-bias

Changes are reported for a group paired-associate learning method developed earlier by the writer. The major improvement allows Ss to score their own performance records in a manner which generates a document that can be give directly to key-punch operators for recording onto Hollerith cards for computer analysis. Possibility of E -bias in scoring is thus completely avoided. Communality between results obtained with the group and the individual (memory drum) methods is discussed; technical advantages of the group method are presented.
MASTOCYTOSIS AND THE SKIN

The most frequent site of organ involvement in individuals with any form of mastocytosis is the skin. Cutaneous lesions include urticaria pigmentosa, mastocytoma, diffuse and erythematous cutaneous mastocytosis, and telangiectasia macularis eruptiva perstans. The major histologic feature is an increase in the number of mast cells in the dermis. Treatment depends on the type of skin lesions.
Passive Stiffness in Drosophila Indirect Flight Muscle Reduced by Disrupting Paramyosin Phosphorylation, but Not by Embryonic Myosin S2 Hinge Substitution

High passive stiffness is one of the characteristic properties of the asynchronous indirect flight muscle (IFM) found in many insects like Drosophila. To evaluate the effects of two thick filament protein domains on passive sarcomeric stiffness, and to investigate their correlation with IFM function, we used microfabricated cantilevers and a high resolution imaging system to study the passive IFM myofibril stiffness of two groups of transgenic Drosophila lines. One group (hinge-switch mutants) had a portion of the endogenous S2 hinge region replaced by an embryonic version; the other group (paramyosin mutants) had one or more puta- tive phosphorylation sites near the N-terminus of paramyosin disabled. Both transgenic groups showed severely compromised flight ability. In this study, we found no difference (compared to the control) in passive elastic modulus in the hinge-switch group, but a 15% reduction in the paramyosin mutants. All results were corroborated by muscle fiber mechanics experiments performed on the same lines. The fact that myofibril elasticity is unaffected by hinge switching implies alternative S2 hinges do not critically affect passive sarcomere stiffness. In contrast, the mechanical defects observed upon disrupting paramyosin phosphorylation sites in Drosophila suggests that paramyosin phosphorylation is important for maintaining high passive stiffness in IFM myofibrils, probably by affecting paramyosin's interaction with other sarcomeric proteins.
Stress reduction by geometric compliance matching at vascular graft anastomoses

An analysis is presented of stresses developed with different junctional configurations of end-to-end vascular graft anastomoses with severe compliance mismatch. Junctions of circular transverse sections and junctions by bias cuts (beveled ends) are compared with an anastomosis of a graft constructed with an elliptical transverse section and a bevel end cut vessel. This latter substitutes midwall inextensional deformations for extensional deformations that occur with the former, conventional configurations. Applications to end-to-side anastomoses are also discussed. A range of parameters are considered:i.e., vascular wall thickness/radius ratios between 0.1 and 0.5 locations from the anastomotic plane between 1/2 and 3/2 times the vascular wall thickness, host vessel axial stretch by external forces between 0 and 15%, maximal vascular circumferential stretch distal from the anastomosis between 0 and 25%, and perimeter locations at the anastomotic junction 0° and 90°. The graft constructed with an elliptic cross-section developed peak stresses that are orders of magnitude lower than those developed with conventional configurations. The introduction of matching geometric compliance that domimates at the anastomotic junction minimizes consequences of material mismatch between graft and vessel and has the potential to reduce suture line stress greatly. This analysis may suggest designs for experimental studies to confirm relationships between neointimal hyperplasia and suture line stress levels, and provide a relatively simple solution for reduction of such stresses at the anastomotic junction. Choices may be permitted of graft materials with optimal surface properties despite less favorable elastic properties.
3H(p,γ)4He reaction from 3 TO 18 MeV

Abstract The 3 H(p,γ) 4 He cross section has been measured at 90° from 3 to 18 MeV proton energy, at 0° from 4 to 14 MeV, and complete angular distributions were taken at 10.5, 12 and 14 MeV. The c.m. angular distributions are consistent with A + B sin 2 θ + C sin 2 θ cos θ + D sin 2 θ cos 2 θ as expected for mixed E1 and E2 radiations. Using our and other results, the integrated 4 He(γ,p) 3 H cross section, computed from the reciprocity relation, is decomposed into E1 and E2 contributions up to E γ ∼ 30 MeV. Extrapolations for the relative contributions are proposed up to E γ ∼ 150 MeV. After removal of kinematic factors, the E1 contribution is shown to be resonant, but the E2 contribution is not resonant. Interpretation of the coefficient ratio A B by Crone and Werntz shows that M2 contributions have an important effect on the magnitude of this coefficient. If the 4 He level scheme of Werntz and Meyerhof is accepted, the singlet strength in the two T = 1,1 − levels appears to lie predominantly in the lower level, in contrast to findings from 3 He(p, p) scattering and polarization measurements.
Stress, social support, and delayed skin barrier recovery.

Objective:To examine the effect of a brief laboratory stressor and social support before the stressor on cardiovascular and cortisol responses, and skin barrier recovery after skin disruption.Methods:Eighty-five healthy participants (mean age 22.9 ± 4.4 years) underwent a “tape-stripping” procedure
Evidence for senescent convergence during human aging.

Abstract ‘Senescent convergence’ is the observation that, with advancing age, multiple measurements of organ/body size, chemistry or function, reveal values for the higher percentiles which decrease faster than those of the lower percentiles. That is, values of the extremes appear to be converging with advanced age. In some cases, the equations for describing this can be modified to include a term that accounts for the percentile of the observation. Examples were given of calculating the age at which values of 2 different percentiles, of the property being measured, become identical (‘age at convergence’). Exceptions to senescent convergence, such as related to diseases like osteoporotic vertebral fractures, were mentioned. It was noted that the curves of senescent convergence resembled the inverse of those of postnatal growth.
Estimating the impact of government R&D

Abstract If we do not pay for an input it is important? It is suggested that the R&D literature, by ignoring the fact that government R&D is given away, has confused zero value of marginal product with zero marginal physical product.
Exploring nutrition education resources and barriers, and nutrition knowledge in teachers in California.

Abstract Objective To determine barriers to nutrition education, nutrition education resources used, and the relationship between nutrition knowledge and whether public school teachers in California teach nutrition in the classroom. Methods A total of 102 teachers in California participated in a Web-based survey about nutrition education barriers, resources used to plan nutrition lessons, and factors that would encourage inclusion of nutrition. A validated questionnaire was used to assess nutrition knowledge. Analyses included ordinary least-squares regression. Results Common barriers were lack of instructional time and unrelated subject. Teachers were unaware of many nutrition education resources. Nutrition knowledge was not associated with nutrition lessons but was positively associated with teaching high school (β = 5.13; P P P Conclusions and Implications Barriers of time and lack of unrelated subject matter are difficult to address but lack of awareness of resources indicates that promotion of existing resources may encourage teachers to provide nutrition education. Larger studies are needed to determine whether this holds true in a broader sample.
Effect of ocular torsion on A and V patterns and apparent oblique muscle overaction.

Objective To determine if ocular torsion is a major cause of A and V patterns and oblique muscle overaction or merely a contributing factor. Methods Three separate investigations were conducted. (1) The trajectory of eyes with oblique muscle overaction was plotted across the horizontal field of gaze from videographs to determine if it was linear or curvilinear. (2) The effect of successful Harada-Ito surgery to reduce extorsion on overelevation in adduction in patients with fourth cranial nerve palsy was studied. (3) The effect of successful surgery to treat pattern strabismus in the form of vertical transposition of the horizontal rectus muscles on objective torsion was studied. Results (1) Three eyes with inferior oblique muscle overaction and 2 with superior oblique muscle overaction had a curvilinear rise or fall (respectively) as they moved into adduction. (2) Surgery that successfully decreased extorsion had a negligible effect on overelevation in adduction in 2 patients. (3) Horizontal rectus muscle transposition that was uniformly successful in eliminating A or V patterns consistently caused an increase in objective torsion in all 5 patients studied. Conclusion Ocular torsion may contribute to A or V patterns and overelevation or overdepression in adduction, but it is probably not the major cause of these phenomena.
Practical Courses in French

FOR some years previous to 1929 all freshmen entering Rutgers University with three years' preparation in French had been assigned to a course in the history of literature. In that year, in response to a demand for more stress on the "practical" phases of language work, a new program was devised. In the new curriculum, composition and conversation at once assumed a place of prime importance. The purpose of the present article is to outline briefly this plan, which is still in force, without entering into any discussion of the relative advantages of literary or reading courses on the one hand, and work in the spoken language on the other. First-year course.-Every freshman who wishes to study French is placed in a course in which special emphasis is laid upon the use of the spoken language. If he is a beginner, his course meets six times a week. Inasmuch as the preparation required is only that expected in a three-hour course, his only additional time-load consists of the three extra hours spent in the classroom. All who have taught elementary language classes know the futility of attempting in a three-hour course to give anything like adequate time to oral practice. It was to obviate this difficulty that the number of class exercises was extended from three to six. Upon the completion of this elementary course, the higher-standing students are admitted to the course to which are assigned freshmen who have had three years of preparation in high school, and they acquit themselves there very creditably. At the mid-year examination last winter, among the forty-five students in the more advanced course, of the four attaining a grade of ninety or above, one had received his only preparation in our elementary six-hour course. Cases of this kind furnish the best evidence that the results justify the innovation.
Isolation of Monoclonal Antibodies Monospecific for Bovine κ-Casein

Bovine kappa-casein represents a major portion of the total protein present in milk and is required for formation of the caseinate micelles responsible for the transportation of both calcium and phosphorous. Two monoclonal antibodies directed against bovine kappa-casein have been isolated. Both monoclonal antibodies are highly specific for bovine kappa-casein. Western analysis of denatured kappa-casein suggests epitope specificity is, in part, conformationally dependent. Additional epitope mapping with chymosin and neuraminidase also suggest antibody binding is in the region of the amino acid sequence Pro-Thr-Thr at positions 92 to 94 and 134 to 136.
Neural mechanisms of auditory categorization: from across brain areas to within local microcircuits

Categorization enables listeners to efficiently encode and respond to auditory stimuli. Behavioral evidence for auditory categorization has been well documented across a broad range of human and non-human animal species. Moreover, neural correlates of auditory categorization have been documented in a variety of different brain regions in the ventral auditory pathway, which is thought to underlie auditory-object processing and auditory perception. Here, we review and discuss how neural representations of auditory categories are transformed across different scales of neural organization in the ventral auditory pathway: from across different brain areas to within local microcircuits. We propose different neural transformations across different scales of neural organization in auditory categorization. Along the ascending auditory system in the ventral pathway, there is a progression in the encoding of categories from simple acoustic categories to categories for abstract information. On the other hand, in local microcircuits, different classes of neurons differentially compute categorical information.
Role of Insulin Signaling in Maintaining Energy Homeostasis

Abstract Objective To examine the role that insulin signaling plays in modulating metabolic functions involving both peripheral and hypothalamic systems. Methods We review the literature regarding insulin signaling as it relates to energy homeostasis. Results Insulin signaling in the periphery is known to affect hepatic glucose production and glucose uptake in muscle and adipose tissue. In the brain, insulin is involved in a variety of signaling pathways that control positive and negative aspects of food intake and energy metabolism. Disruption of insulin signaling can affect key cellular pathways that serve to maintain energy balance and glucose homeostasis, which can then lead to insulin resistance and progression toward various metabolic disorders, including cardiovascular disease, obesity, and type 2 diabetes. The use of exogenous insulin as therapy for patients with type 2 diabetes is traditionally associated with increases in weight. Conclusion An enhanced understanding of how these insulin signaling pathways function may provide answers about how to control weight gain associated with exogenous insulin use. Pharmacologic agents, such as the long-acting insulin analogues and particularly insulin detemir, that may reduce these weight effects hold considerable advantage. (Endocr Pract. 2008;14:373-380)
Current filaments in semiconductors

A current filament is a non-uniform radial distribution of current in the presence of a uniform electric field ina uniform sample. These filaments can have diameters in the 0.005 inch range. The current density at the center of the filament can be several orders of magnitude higher than the background current density in the rest of the sample. Filaments have been studied in devices exhibiting the current-controlled negative resistance associated with specific cases of two-carrier space-charge-limited current double injection. Electrons and holes are injected from opposite contacitns to a semi-insulator in which the lifetime of carriers of one sign is much longer than the lifetime of carriers of the opposite sign. When forward biased this device exhibits a high-voltage, high-impedance (108 ohms) pre-breakdown region and a low-voltage, low-impedance (1 to 103 ohms) post-breakdown region. In the post-breakdown region current increases ata nearly constant voltage followebdy a high-current power-law region. Current filaments have been studied throughout the post-breakdown region by recording the recombination radiation observed through one of the injecting contacts. Experimental and analytical studies of current filaments in silicon at 77°K and GaAs at 300°K are reviewed.
An all sodium iodide anticoincidence shielded total absorption spectrometer for low-level radionuclide analyses

Abstract An anticoincidence shielded gamma-ray spectrometer has been designed from a 34 cm dia. by 31 cm thick NaI(Tl) ingot which surrounds an 18 cm dia. by 22 cm thick NaI(Tl) principal detector. The spectrometer and the principal crystal are hermetically sealed in a single container. Low background construction materials, as well as low 40 K content phototubes, serve to reduce the background. The low 40 K phototubes reduced the 40 K detected by the principal crystal approximately twofold compared to standard glass phototubes. The background in the energy range from 0.1 to 3 MeV was reduced from two- to fivefold by the anticoincidence shield. The efficiency of the system for a point and a 70 ml source is approximately fivefold greater than that of a 7.5 cm dia. by 7.5 cm thick NaI(Tl) crystal. By means of the anticoincidence crystal, the Compton edge for 137 Cs was reduced by 2.5-fold to produce a peak-to-Compton edge ratio of approximately 160: 1. The system has been utilized for low-level radionuclide analyses of single gamma-ray emitters and has been compared to NaI(Tl) multidimensional and Ge(Li) gamma-ray spectrometers.
Sex and emotion in the acquired capability for suicide.

This article examined the impact of distress tolerance on sex differences in the acquired capability for suicide. Two hundred undergraduate participants filled out a series of questionnaires related to emotions and suicide risk. Males exhibited higher mean levels of the acquired capability than did women and distress tolerance interacted with sex to predict the acquired capability (β = −.70, p < .02), such that males with high distress tolerance were at the greatest risk. These results indicate that the degree to which an individual can tolerate negative emotions impacts the strength of the relationship between sex and the acquired capability for suicide.
A multivariate generalization of the FRIEDMAN rank test with application to a problem in molecular biology

A series of experiments was recently undertaken at the National Institutes of Health to ascertain whether tRNA populations are determined by or adapted to the major proteins synthesized by tumor cells. Dissimilarity indices between chromatographic profiles of animoacyl-tRNAs from 11 mouse plasmacytomas and from normal adult mouse liver and brain were calculated and then compared using a multivariate generalization of the FRIEDMAN rank test. This test is described herein, and its use is illustrated with data from the experiments.
Some applications of local density functional theory to the calculation of reaction energetics

We report the results of a local density functional investigation of the energetics of some isomerization reactions, involving the conversions of several unsaturated systems to highly strained molecules related to triprismane and tetrahedrane. The program DMol was used at the DNP level to compute the activation barriers and total energy changes associated with these processes. We also show, for more than 70 first- and second-row atoms and molecules, that the errors (non-local corrections) in their energies correlate very well with the number of electrons, within isonuclear series. This should provide a useful empirical means for improving dissociation energies obtained within the local approximation.
Restraint Use by Children Involved in Crashes in Hawaii, 1986-1991

The use of child safety seats for crash-involved children in Hawaii from 1986 through 1991 is described. Child safety seat use increased over this period, whereas unrestrained children and belt use for children decreased. Male drivers are more likely to have unrestrained infants; female drivers are more likely to have unrestrained toddlers. Toddlers are more likely to be unrestrained in automobiles and trucks, and infants are more likely to be unrestrained in vans, on the freeway, during nighttime hours, and in urban areas. Child-restraint use for infants is twice the rate for toddlers, and infants are less likely to suffer nonincapacitating, incapacitating, and fatal injuries. A logistic regression model shows that children riding in automobiles are less likely to be restrained; belted drivers are far more likely to restrain children; and one- and two-year-olds are less likely to be restrained. Separate logistic regressions for crash types reveals that restrained children are less likely to suffer a noni...
Accelerator based techniques for contraband detection

Abstract It has been shown that narcotics, explosives, and other contraband materials, contain various chemical elements such as H, C, N, O, P, S, and Cl in quantities and ratios that differentiate them from each other and from other innocuous substances. Neutrons and γ-rays have the ability to penetrate through various materials at large depths. They are thus able, in a non-intrusive way, to interrogate volumes ranging from suitcases to Sea-Land containers, and have the ability to image the object with an appreciable degree of reliability. Neutron induced reactions such as (n, γ), (n, n') (n, p) or proton induced γ-resonance absorption are some of the reactions currently investigated for the identification of the chemical elements mentioned above. Various DC and pulsed techniques are discussed and their advantages, characteristics, and current progress are shown. Areas where use of these methods is currently under evaluation are detection of hidden explosives, illicit drug interdiction, chemical war agents identification, nuclear waste assay, nuclear weapons destruction and others.
Universal screening for group B streptococcus: Recommendations and obstetricians' practice decisions

Objective: To determine how obstetricians' opinions regarding universal screening of pregnant women for group B streptococcus (GBS) and their responses to positive culture results vary from American Academy of Pediatrics recommendations, and to determine the physician characteristics that predict divergent opinions. Methods: One hundred ninety-four practicing obstetricians in the middle Tennessee region were queried by a mail survey. They were asked if they agreed with universal screening for GBS and to indicate whether they would prescribe antibiotics for women in labor, represented by six scenarios that differed with respect to presence or absence of preterm labor, premature rupture of membranes (ROM), prolonged ROM, and a positive GBS cervical culture. They were also asked to describe their practice and personality characteristics. Results: Completed surveys were returned by 135 of 194 obstetricians (70%). Although only 28% of the respondents agreed with routine prenatal screening for GBS, most (74%) said they would treat a patient on the basis of a positive culture alone. Other risk factors, when added to a positive culture, slightly increased the decision to treat (from 74 to 88%). Multiple logistic regression, used to assess the relative effect of clinical and physician characteristics on treatment decisions, revealed that chemoprophylaxis for GBS was predicted most strongly by a positive culture at 28 weeks' gestation followed by prolonged ROM and preterm labor. Practicing in an urban location and seeing fewer than 20 patients per day also influenced the decision to treat. Conclusion: Although most obstetricians in the middle Tennessee region do not believe in universal screening, most will prescribe intrapartum antibiotics on the basis of a positive screening culture. However, other clinical risk factors and physician characteristics significantly and independently affect the decision to treat as well.
Spectrum of vascular pathology affecting patients with the antiphospholipid syndrome

A thrombotic microangiopathy that is identified in patients with the antiphospholipid syndrome (APS) represents only a part of the vascular pathology that can be associated with antiphospholipid antibodies (aPL). Tissues from two autopsies, four renal biopsies, two skin biopsies, and one amputated leg were obtained from six patients who met criteria for the diagnosis of APS. Three patients had systemic lupus erythematosus (SLE), one had lupus-like disease, and two had a primary APS. Five of the patients were hypertensive. Arteries of three patients disclosed fibrin thrombi along with widespread obstruction by recanalized intimal connective tissue. Small renal, leptomeningeal, and pulmonary arteries showed concentric cellular and fibrous intimal hyperplasia indistinguishable from hypertensive vascular disease. Glomerular capillary and afferent arteriolar thrombi were found in renal biopsies from two SLE patients. One of these SLE patients required a leg amputation in which the popliteal artery demonstrated thrombosis, intimal hyperplasia, and acute inflammation. The findings support clinical and experimental data that indicate aPLs cause thrombosis but suggest diversity in the pathogenetic mechanisms aPLs are capable of promoting. Inflammation seems to be rare and to accompany thrombosis. Intimal hyperplasia is particularly common. Its involvement of renal arteries may contribute to hypertension that develops in some APS patients.
New developments in therapy for colorectal cancer

Colorectal cancer remains a significant cause of cancer death, and its treatment is the subject of active, ongoing investigation within all treatment modalities, including surgery, chemotherapy, and radiotherapy. In this review we discuss selected interesting and important research findings since the year 2000 and comment on their potential impact on the adjuvant and advanced disease management of patients with colon and rectal cancer.
The relationship of intercompartmental excitation transfer rate constants to those of an underlying physical model.

In studies on photosynthetic systems it is common practice to interpret the results of time-resolved fluorescence experiments on the basis of compartmental, or target, models. Each compartment represents a group of molecules with similar fluorescence characteristics. In cases of practical interest, the members of each compartment are spatially contiguous and make up part of an overall energy-transferring system. Since a rate constant describing the overall transfer between compartments is not that of any pair of molecules in the system, this question naturally rises: what do we learn about the microscopic structure from these data? In this note we introduce ‘compartment melting’, a smooth mathematical connection between the compartmental and microscopic levels. We then show, on the basis of model calculations on finite lattices in one, two, and three dimensions, that average microscopic rates at the interfaces between compartments may be estimated from observed intercompartmental rates. The estimate involves a modest number of structural assumptions about the system. As examples of the method, which is applicable mainly to systems containing homogeneous pigment pools, some recent chlorophyll-protein antenna studies are analyzed.
Image restoration and reconstruction with a Bayesian approach

We have extended Johnson's Bayesian method for image restoration and reconstruction by introducing diagonal line sites, using symmetric neighborhood configurations, and employing an additional hyperparameter for estimation of line sites. A general formulation for arbitrary neighborhood configurations was derived. The major part of this paper deals with the conduct of computer simulations intended to examine the effect of the hyperparameters, the diagonal line sites, and the size of the neighborhood configuration on the performance of the proposed Bayesian method. We show that, for optimal performance, distinct hyperparameters should be used for the intensity sites and line sites. The results also suggest that a large neighborhood configuration should be used. By comparing the near-optimal restored images, we demonstrated that the use of diagonal line sites, along with the symmetric configurations thus made possible, can effectively remove the blocky edge artifacts and produce images of better quality. When the method was applied to positron emission tomography (PET) image reconstruction, our results showed that the quality of the reconstructed images was improved for both computer-simulated and real patient PET data.
Intracellular RNA cleavage by the hairpin ribozyme.

Studies involving ribozyme-directed inactivation of targeted RNA molecules have met with mixed success, making clear the importance of methods to measure and optimize ribozyme activity within cells. The interpretation of biochemical assays for determining ribozyme activity in the cellular environment have been complicated by recent results indicating that hammerhead and hairpin ribozymes can cleave RNA following cellular lysis. Here, we report the results of experiments in which the catalytic activity of hairpin ribozymes is monitored following expression in mammalian cells, and in which post-lysis cleavage is rigorously excluded through a series of biochemical and genetic controls. Following transient transfection, self-processing transcripts containing active and inactive hairpin ribozymes together with cleavable and non-cleavable substrates were generated within the cytoplasm of mouse OST7-1 cells using T7 RNA polymerase. Unprocessed RNA and products ofintracellular cleavage were detected and analyzed using a primer-extension assay. Ribozyme-containing transcripts accumulated to a level of 4 x 10(4) copies per cell, and self-processing proceeded to an extent of >75% within cells. Cellular RNA processing was blocked by mutations within the ribozyme (G8A, G21U) or substrate (DeltaA-1) that, in vitro , eliminate cleavage without affecting substrate binding. In addition to self-processing activity, trans -cleavage reactions were supported by the ribozyme-containing product of the self-processing reaction, and by the ribozyme linked to the non-cleavable substrate analog. Ribozyme activity was present in extracts of cells expressing constructs with active ribozyme domains. These results provide direct biochemical evidence for the catalytic activity of the hairpin ribozyme in a cellular environment, and indicate that self-processing ribozyme transcripts may be well suited for cellular RNA-inactivation experiments.
Molecular Characterization of Trypanosoma brucei P-type H+-ATPases

Abstract Previous studies in Trypanosoma brucei have shown that intracellular pH homeostasis is affected by inhibitors of H+-ATPases, suggesting a major role for these pumps in this process (Vander-Heyden, N., Wong, J., and Docampo, R., (2000) Biochem. J. 346, 53-62). Here, we report the cloning and sequencing of three genes (TbHA1, TbHA2, and TbHA3) present in the genome of T. brucei that encode proteins with homology to fungal and plant P-type proton-pumping ATPases. Northern and Western blot analyses revealed that these genes are up-regulated in procyclic trypomastigotes. TbHA1, TbHA2, and TbHA3 complemented a Saccharomyces cerevisiae strain deficient in P-type H+-ATPase activity, providing genetic evidence for their function. Indirect immunofluorescence analysis showed that TbHA proteins are localized mainly in the plasma membrane of procyclic forms and in the plasma membrane and flagellum of bloodstream forms. T. brucei H+-ATPase genes were functionally characterized using double-stranded RNA interference methodology. The induction of double-stranded RNA (RNA interference) caused growth inhibition, which was more accentuated in procyclic forms and when expression of all TbHA proteins was decreased. Knockdown of TbHA1 and TbHA3, but not of TbHA2, resulted in cells with a lower steady-state pHi and a slower rate of pHi recovery from acidification. No evidence was found of an intracellular P-type H+-ATPase activity. These results establish that T. brucei H+-ATPases are plasma membrane enzymes essential for parasite viability.
Arachidonic acid signaling to the cytoskeleton: the role of cyclooxygenase and cyclic AMP-dependent protein kinase in actin bundling.

Cell adhesion to the extracellular matrix via integrins is a primary regulatory mechanism for numerous aspects of normal cellular function. However, disruption of this interaction can result in pathology. For example, one characteristic of transformed cells is loss of adhesion dependence for viability. Adhesion also is a necessary step in tumor metastasis. It has been shown previously, in HeLa cells, that cell attachment to a gelatin-coated substrate results in the release of arachidonic acid, which is metabolized by lipoxygenase. A subsequent cascade of lipid second messengers activates protein kinase C, which triggers actin polymerization leading to cell spreading. We now demonstrate by inhibitor studies and biochemical analysis, a parallel branch of arachidonic acid signaling that reorganizes the actin cytoskeleton into small bundles. This branch of the pathway is initiated by cyclooxygenase, which generates prostaglandins and causes the downstream activation of cyclic AMP-dependent protein kinase. This work elucidates a system of interacting signals in which arachidonic acid functions at a branch point in cytoskeletal signaling. The lipoxygenase branch provides polymerized actin; these actin filaments act as a substrate for the cylooxygenase branch to generate actin bundles. Cell Motil. Cytoskeleton 53:239–250, 2002. © 2002 Wiley-Liss, Inc.
Study on the Fatigue Reliability Model Based on Probability Distribution of Fatigue Life under Spectrum Loading

Under variable amplitude load history the exact distribution of fatigue strength corresponding to a specified number of life cycles cannot be obtained exactly by test, fatigue strength distribution can be obtained from fatigue life distribution. According to statistical property analysis of Miner cumulative damage rule, probability distribution of fatigue life under variable amplitude load history is predicted based-on constant amplitude median Sa-Sm-N surface. In the end, a fatigue reliability model is established to calculate fatigue reliability according to stress distribution as well as fatigue life distribution function. The model is applicable to calculate fatigue reliability under stochastic load environments.
Calcium hydroxide and calcium carbonate particle size effects on reactivity with sulfur dioxide

The effect of in situ calcium hydroxide [Ca(OH2)] and calcium carbonate (CaCO3) sorbent particle size upon reactivity with 3000 ppm sulfur dioxide (SO2) in an 1100°C drop-tube furnace was measured by on-line collection of the reacted sorbent with a particle cascade impactor. Significant agglomeration occurred for the hydroxides, while little was apparent for the carbonate. Reactivity of all sorbent particles increases as the measured particle diameter decreases such that conversion is inversely related to diameter to the 0.22–0.32 power. For these sorbents, Ca(OH)2 particles had greater reactivity than the similarly sized CaCO3 sorbent.
Sol-gel derived amperometric nitric oxide microsensor.

An amperometric sol−gel derived nitric oxide microsensor is described. Several silicon-based xerogel membranes are evaluated to identify the optimum composition for maximizing NO permeability while providing sufficient selectivity for NO in the presence of common interfering species. Xerogel permeability and selectivity are further manipulated as a function of reaction/processing conditions. In addition, the effects of incorporating Nafion into the xerogel matrix on sensor performance and the stability of the ensuing xerogel/Nafion hybrid film are evaluated. The optimal permselective membrane is achieved by catalyzing polycondensation of the xerogel composed of methyltrimethoxysilane and (aminoethylaminomethyl)phenethyltrimethoxysilane and Nafion with NO gas. The resulting NO microsensor exhibits a sensitivity of 0.17 ± 0.02 pA/nM (from 25 to 800 nM, r = 0.9991), detection limit of 25 nM (S/N = 3), response time of 9 s (t95%, a NO concentration change from 400 to 500 nM), selectivity (log ) of −5.8, <−6, ...
Historical Experiments in Students’ Hands: Unfragmenting Science through Action and History

Two students, meeting together with a teacher, redid historical experiments. Unlike conventional instruction where science topics and practices often fragment, they experienced interrelatedness among phenomena, participants’ actions, and history. This study narrates actions that fostered an interrelated view. One action involved opening up historical telephones to examine interior circuitry. Another made sound visible in a transparent air column filled with Styrofoam bits and through Lissajous figures produced by reflecting light off orthogonal nineteenth century tuning forks crafted by Koenig and Kohl. Another involved orienting magnetic compasses to reveal the magnetism of conducting wires, historically investigated by Oersted and Schweigger. Replicating Homberg’s triboluminescent compound elicited students’ reflective awareness of history. These actions bore pedagogical value in recovering some of the interrelatedness inherent in the history and reintroducing the wonder of science phenomena to students today.
Thermodynamics of binary and larger organic-organic and organic-water systems

Abstract We have applied our model to the enthalpy and excess Gibbs energy of mixing data of the binary systems Ethanol-Methylcyclohexane, Water-methylacetate, -ethylacetate, -butylacetate and -pentylacetate, and to the ternary systems Acetonitrile-Benzene-Carbon Tetrachloride, Ethanol—Chloroform—1,4-Dioxane, Cyclohexane—2-Propanol—Water, and to the quaternary system Ethyl Alcohol—n-Hexane—Benzene—Methylcyclopentane. In all cases our model uses only maximum two interaction parameters for each binary and no ternary or larger parameters are needed. Our model can describe all above the systems very well.
Beliefs About Participation-Based Practices in Early Intervention

Researchers have noted divergent findings with respect to the relationships of practitioners’ beliefs and their implementation of recommended practices. With Q-sort methods, this study examined practitioners’ beliefs about practices in early intervention with samples of current practitioners (n = 211) and preservice students (n = 142). Findings indicated that practitioners rated participation-based practices as less strongly held beliefs when compared with several other early intervention practices, and students’ responses revealed beliefs that were in contrast with participation-based beliefs. In addition, results showed that practitioners’ beliefs were more similar to respondents from institutions of higher education than were the preservice students.
Analysis of the human zona pellucida during culture: Correlation with diagnosis and the preovulatory hormonal environment

Purpose: The objective of this study was to analyze sequentially the human zona pellucida changes in an in vitro fertilization program as it relates to several variables. Methods: The zona pellucida thickness was measured daily in zygotes and cleavage-stage embryos on a Nikon inverted microscope equipped with Hoffman modulation contrast optics, using an ocular micrometer. A total of 512 embryos from 96 patients was evaluated. Results: There was a highly significant direct correlation between zona thickness and preovulatory estradiol and basal day 3 FSH levels (P < 0.02 andP < 0.0006, respectively). This relationship showed a rapid reversal following 48 hr of culture; embryos from patients with the highest FSH levels had thinner zonae prior to transfer (P < 0.0007). The zonae from patients with unexplained infertility were thicker (19.4 ± 2.7 µm) than those from patients with endometriosis (17.7 ± 2.2 µm), tubal (17.5 ± 2.4 µm), or male-factor infertility (16.4 ± 2.7 µm) (P < 0.0001) on the first day of culture. Conclusions: We hypothesize that the thickness of the human zona pellucida is influenced by the preovulatory hormonal environment and diagnosis. These factors should be considered as part of the embryo quality evaluation prior to transfer or when assessing the possibility of using assisted hatching. More studies are needed to understand the factors regulating the thickness of the human zona pellucida.
Mesonephric Remnant Hyperplasia of the Cervix: A Clinicopathologic Analysis of 14 Cases

Lesions derived from mesonephric remnants in the uterine cervix are rare. We describe 14 patients with benign, hyperplastic mesonephric remnant lesions. The patients ranged in age from 31 to 81 years (mean, 47). Four were postmenopausal. The lesions were incidental findings in all but 2 of the patients and frequently had been submitted for consultative pathologic opinion. Two patients did, however, present with symptoms (vaginal bleeding) likely attributable to their lesions and 1 of them had a cervical abnormality on clinical examination. Microscopically, the lesions were composed of lobular or diffuse proliferations of small, round mesonephric tubules which were frequently deep within the cervical wall and often extended to the surface of the cervix. Five of the patients had a referring diagnosis of probable or definite cervical adenocarcinoma due to the infiltrative appearance of the lesions. No mesonephric carcinomas were encountered. Hyperplastic lesions of mesonephric remnants are usually benign, incidental findings but may on occasion be associated with clinical symptomatology and are a potential source of diagnostic confusion for the pathologist.
CO2 Flood: Design and Initial Operations, Ford Geraldine (Delaware Sand) Unit

A miscible carbon dioxide (CO) flood was initiated by Conoco Inc. in a 3850-acre area of the Ford Geraldine (Delaware Sand) Unit in Reeves and Culberson Counties, Texas in February, 1981, after a staged waterflood was nearing completion. The CO supply is a by-product source obtained from the Lone Star Pikes Peak Gas Plant near Fort Stockton. This previously vented product is compressed to a supercritical state and then transported to the Unit through a 112-mile pipeline which has a capacity of 30 MMCFPD. Compression and transmission system design has minimized start-up and operational problems. Capital costs were reduced by utilizing most of the existing waterflood distribution system. Lack of a sufficient and stable CO supply has caused most of the operational problems. New vessels have been installed to better handle production well testing. In addition, a system has been developed and installed to automate all injection and production data so as to provide the surveillance information to properly monitor the flood performance. Response to the limited and unstable CO injection supply has been encouraging. Once additional supplies are secured and response is verified, CO recycle facilities will be installed. In addition, the flood could later be expanded to themore » remaining 1430-acre northern area of the Unit, which is still under waterflood.« less
Incorporation of a multiscale texture-based approach to mutual information matching for improved knowledge-based detection of masses in screening mammograms

Mutual information is a popular intensity-based image similarity measure mainly used in image registration. This measure has been also very successful as the similarity metric in our knowledge-based computer-assisted detection (CADe) system for the detection of masses in screening mammograms. Our CADe system is designed to assess a new, query case based on its similarity with known cases stored in the knowledge database. However, intensity-based mutual information captures only relationships between the gray level values of corresponding pixels. This study presents a novel advancement of our CADe system by incorporating neighborhood textural information when estimating the mutual information of two images. Specifically, an entropy filter is applied to the images, effectively replacing each image pixel value with its neighborhood entropy. This pixel-based entropy is a localized measure of image texture. Then, the information-theoretic CAD system is asked to make a decision regarding the query case using the texture-based mutual information similarity metric. The entropy-based image enhancement and MI-based decision making processes are repeated at different neighborhood scales. Finally, an artificial network merges intensity-based and texture-based decisions to investigate possible improvements in mass detection performance. Given a database of 1,820 regions of interest (ROIs) extracted from screening mammograms (901 depicting a biopsy-proven mass and 919 depicting normal parenchyma) and a leave-one out sampling scheme, the study showed that our CADe system achieves an ROC area of 0.87±0.01 using the intensity-based ROC. The ROC performance for the texture-based CADe system ranges from 0.69±0.01 to 0.83±0.01 depending on the scale of analysis. The synergistic approach of the ANN using both intensity-based and texture-based information resulted in statistically significantly better performance with an ROC area index of 0.93±0.01.
Risk Factors for Fatal Breast Cancer in African-American Women and White Women in a Large US Prospective Cohort

African-American women have a higher lifetime risk of fatal breast cancer than do White women. Recent studies suggest that breast cancer risk factors may vary by race. The authors examined risk factors for fatal breast cancer in postmenopausal African-American women and White women in a large US prospective cohort. In 1982, 21,143 African-American women and 409,093 White women in the Cancer Prevention Study II completed a questionnaire on reproductive, medical, anthropometric, and demographic factors. During a 20-year follow-up, 257 deaths from breast cancer occurred among African-American women and 4,265 among Whites. Cox proportional hazards modeling was used to calculate multivariate-adjusted rate ratios, stratified by race. Higher body mass index, taller height, and physical inactivity were associated with increased breast cancer mortality rates in both groups. A college education was associated with higher mortality from breast cancer only in Africa-American women (hazard ratio = 1.62, 95% confidence interval: 1.13, 2.30; p(trend) = 0.01, vs. less than a high school education). Most other risk factors were associated with breast cancer rates similarly in both groups. With few exceptions, established breast cancer risk factors were similarly associated with risk of death from breast cancer among African-American women and White women.