cssi/SciSciGPT-SciSciNet huggingface dataset:
Incidental pineal cysts in children who undergo 3-T MRI

Pineal cysts, both simple and complex, are commonly encountered in children. More cysts are being detected with MR technology; however, nearly all pineal cysts are benign and require no follow-up. To discover the prevalence of pineal cysts in children at our institution who have undergone high-resolution 3-T MRI. We retrospectively reviewed 100 consecutive 3-T brain MRIs in children ages 1 month to 17 years (mean 6.8 ± 5.1 years). We evaluated 3-D volumetric T1-W imaging, axial T2-W imaging, axial T2-W FLAIR (fluid attenuated inversion recovery) and coronal STIR (short tau inversion recovery) sequences. Pineal parenchymal and cyst volumes were measured in three planes. Cysts were analyzed for the presence and degree of complexity. Pineal cysts were present in 57% of children, with a mean maximum linear dimension of 4.2 mm (range 1.5–16 mm). Of these cysts, 24.6% showed thin septations or fluid levels reflecting complexity. None of the cysts demonstrated complete T2/FLAIR signal suppression. No cyst wall thickening or nodularity was present. There was no significant difference between the ages of children with and without cysts. Cysts were more commonly encountered in girls than boys (67% vs. 52%; P = 0.043). There was a slight trend toward increasing pineal gland volume with age. Pineal cysts are often present in children and can be incidentally detected by 3-T MRI. Characteristic-appearing pineal cysts in children are benign, incidental findings, for which follow-up is not required if there are no referable symptoms or excessive size.
Using Video Editing to Cultivate Novice Teachers’ Practice

AbstractThis article reports research concerning the effective use of video editing to help cultivate novice teachers’ reflective practice. The study reported here is part of a larger body of research on video-enhanced teacher reflection. For this study, we used a qualitative research design to examine two guided reflection activities for two groups of novice teachers. The first group debriefed with a teacher educator immediately after teaching their lesson. They later wrote about critical incidents that occurred during their teaching. The second group had no debriefing, but the participants were asked to capture their lessons on digital video, edit their video for two critical incidents, and reflect on the incidents in written form using the same rubric as the first group. Given that both groups used the same reflection guide, we found that students who developed video vignettes produced longer and more multifaceted reflections. We found implications of these results to be an important step towards facil...
Simple quantitative model for the reversible association of DNA coated colloids

We investigate the reversible association of micrometer-sized colloids coated with complementary single-stranded DNA "sticky ends" as a function of the temperature and the sticky end coverage. We find that even a qualitative description of the dissociation transition curves requires the inclusion of an entropic cost. We develop a simple general model for this cost in terms of the configurational entropy loss due to binding and confinement of the tethered DNA between neighboring particles. With this easy-to-use model, we demonstrate for different kinds of DNA constructs quantitative control over the dissociation temperature and the sharpness of the dissociation curve, both essential properties for complex self-assembly processes.
Alterations in the Responsiveness of Median Eminence Luteinizing Hormone-Releasing Hormone Nerve Terminals to Norepinephrine and Prostaglandin E2 in Vitro during the Rat Estrous Cycle

The present study was conducted to determine if the response of median eminence (ME) nerve terminals to norepinephrine (NE) and prostaglandin E2 (PGE2) varies during the 4-day estrous cycle and if so, whether these changes could play a role in neural mechanisms regulating cyclic gonadotropin release. Groups of adult female rats were decapitated at either 1300 or 1600 h on each day of the cycle, blood was collected, and ME fragments (two MEs per flask) were incubated in an in vitro system. After a 15-min preincubation period, basal LHRH and PGE2 release was measured by RIA during a 30-min incubation period, and ME responses to either PGE2 (0.28 /IM) or NE (60 /AM) were tested during a second 30-min incubation period. The basal release of PGE2 and LHRH did not differ significantly among days of the cycle at any time examined. The release of LHRH in response to PGE2 markedly declined between 1300 h on diestrus day 2 (diestrus-2) and 1300 h on proestrus. Coincident with the preovulatory LH surge, the LHRH res...
Early T Cell Response to Allografts Occuring Prior to Alloantigen Priming Up-Regulates Innate-Mediated Inflammation and Graft Necrosis

The early inflammatory response within organ allografts is initiated by ischemia/reperfusion (I/R) and promotes subsequent alloantigen-primed T cell recruitment into and rejection of the graft. Polymorphonuclear leukocyte (PMN)-mediated tissue damage is a primary component of the early inflammation in allograft rejection. We sought to compare and elucidate the mechanism of early PMN infiltration into cardiac isografts and allografts. Despite identical production of PMN attractant chemokines, PMN infiltration following reperfusion into syngeneic and allogeneic grafts was not equivalent. PMN infiltration into isografts peaked at 9 to 12 hours post-transplant and quickly resolved. In contrast, PMN infiltration into allografts continued to elevated levels, peaking at 24 hours post-reperfusion. This amplified PMN infiltration into allografts did not resolve until 72 hours post-reperfusion and was accompanied by marked parenchymal necrosis. This early innate inflammatory response was regulated by IFN-γ-producing CD8 + T cells present in the recipient before detectable alloantigen T cell priming. Co-culture with CD62L low CD8 + T cells, but not CD62L high CD8 + or CD62L low CD4 + T cells, harvested from naive animals induced allogeneic endothelial cells to express IFN-γ-dependent chemokines. These data demonstrate CD8 + T cell-mediated attack on the vascular endothelium of allografts within hours following organ reperfusion that amplifies innate immune-mediated intra-graft inflammation and necrosis.
Phased scheduling of stream programs

As embedded DSP applications become more complex, it is increasingly important to provide high-level stream abstractions that can be compiled without sacrificing efficiency. In this paper, we describe scheduler support for StreamIt, a high-level language for signal processing applications. A StreamIt program consists of a set of autonomous filters that communicate with each other via FIFO queues. As in Synchronous Dataflow (SDF), the input and output rates of each filter are known at compile time. However, unlike SDF, the stream graph is represented using hierarchical structures, each of which has a single input and a single output.We describe a scheduling algorithm that leverages the structure of StreamIt to provide a flexible tradeoff between code size and buffer size. The algorithm describes the execution of each hierarchical unit as a set of phases. A complete cycle through the phases represents a single steady-state execution. By varying the granularity of a phase, our algorithm provides a continuum between single appearance schedules and minimum latency schedules. We demonstrate that a minimal latency schedule is effective in decreasing buffer requirements for some applications, while the phased representation mitigates the associated increase in code size.
Benzonitrile extrusion from molybdenum(IV) ketimide complexes obtained via radical C-E (E = O, S, Se) bond formation: toward a new nitrogen atom transfer reaction.

Beta-elimination is explored as a possible means of nitrogen-atom transfer into organic molecules. Molybdenum(IV) ketimide complexes of formula (Ar[t-Bu]N)3Mo(NC(X)Ph), where Ar = 3,5-Me2C6H3 and X = SC6F5, SeC6F5, or O2CPh, are formally derived from addition of the carbene fragment [:C(X)Ph] to the terminal nitrido molybdenum(VI) complex (Ar[t-Bu]N)3Mo≡N in which the nitrido nitrogen atom is installed by scission of molecular nitrogen. Herein the pivotal (Ar[t-Bu]N)3Mo(NC(X)Ph) complexes are obtained through independent synthesis, and their propensity to undergo beta-X elimination, i.e., conversion to (Ar[t-Bu]N)3MoX + PhC≡N, is investigated. Radical C−X bond formation reactions ensue when benzonitrile is complexed to the three-coordinate molybdenum(III) complex (Ar[t-Bu]N)3Mo and then treated with 0.5 equiv of X2, leading to facile assembly of the key (Ar[t-Bu]N)3Mo(NC(X)Ph) molecules. Treated herein are synthetic, structural, thermochemical, and kinetic aspects of (i) the radical C−X bond formation and...
The Influence of Eligibility on Employees' Reactions to Voluntary Workforce Reductions

This study examined employees' reactions to a voluntary sever ance program (VSP). Results generally supported a model that links perceptions of justice-based attributes (adequacy of outplacement help; consistency, objectivity, and ethicality of procedures) with affective commitment and intentions to leave. We also considered the main and moderating effects of a particular voluntary severance outcome, eligi bility. Eligibility was associated with both commitment and turnover intentions, and moderated the effect of perceived adequacy of outplace ment help on turnover intentions, as well as the effect of perceived procedural fairness on commitment. Control variables representing demographics (age), perceived fairness of a previous early retirement program, and anticipation of future layoffs also significantly influenced both outcomes. Implications for future research and for management are discussed.
Characterization of Radiation Fields and Dose Assessment From Fuels Manufacturing For Advanced Fuel Cycles

Abstract The purpose of this study was to examine radiological hazards introduced to workers from the fabrication of fuels with minor actinides (MA) and reprocessed uranium (RepU) and determine the feasibility of using shielded gloveboxes instead of remotely controlled operations in hot cells. Of particular concern is the increase in photon source term from the daughter products in RepU and the mixed neutron and photon fields introduced by MA recycle. In the interest of keeping the glovebox worker's radiation dose as low as reasonable achievable (ALARA), dose rates were calculated for various typical and bounding fuel compositions for light water reactors (LWR) and fast reactor (FR) mixed oxide (MOX) fuels with and without MA. The impact of varying the separation efficiency of americium (Am) and curium (Cm) was examined because current separation processes in reprocessing and recycling do not allow for the complete separation of Am from Cm. The additional Cm will cause a significant increase in the neutron source term. The sensitivity of the fuels to aging time was also examined by decaying the recycled feedstocks from 6 months to 3 years to simulate the effect of delays in reuse of recycled materials. The highest photon and neutron sources were used to calculate the additional shielding requirements that would be needed for fuel fabrication. Through insight gained from this study, it can be concluded that a standard glovebox with one quarter inch stainless steel walls can be used to fabricate fuels with Am with little to no additional shielding. The introduction of small amounts of Cm in the fuels will require the fuel fabrication to be preformed remotely in hot cells. Thus, stressing the importance of developing methods to increase the separation efficiency of Am from Cm.
Mean Waiting Time as a Measure of Effectiveness

In the application of probabilistic models to waiting time problems it is sometimes necessary to compare two or more different service patterns to determine which pattern is most effective in decreasing waiting times. In many cases the mean waiting time of the customer is the criterion used to measure the effectiveness of the service because it is the easiest property of the waiting time distribution to calculate. It is the purpose of this note to give an example of a simple waiting time problem in which it is intuitively clear that the mean waiting time gives a misleading indication of the effectiveness of the service and that some other measure should be considered. Suppose there are N independent bus routes passing a particular bus stop A which by different paths arrive at a particular destination point B. Let T,,(') (i = 1, 2, . . . N; n1, 2, . . .) be the instant at which the nth arrival of a bus on the ith route occurs at point A. We will assume that On(i) = T1+1'i'Tn"), (n = 1 2 . . .) are independent identically distributed positive random variables such that
Benzo[b]thiophene derivatives. XXI. On the proof of structure of the sulfur isostere of psilocin

Differences in the characteristics of several common compounds reported in two independent syntheses of the sulfur analog of psilocin required re-examination of our products. Additional evidence supporting the structures previously reported by us is presented. This includes proof of 3-substitution in 4-methoxy-3-β-dimethylaminoethylbenzo[b]thiophene by deuterium exchange of the 2-proton, demonstration that the intermediate 4-methoxy-N, N-dimethyl-3-benzo[b]thienylglyoxamide is different from the 2-isomer, and confirmation of the structure of 4-methoxy-3-methylhenzo[b]thiophene, an intermediate in one of the reported syntheses, by three different synthetic methods.
From Shy Lamb to Roaring Lion: An Acceptance and Commitment Therapy Case Study

The U.S. is becoming more culturally diverse. In order for clinicians to provide appropriate treatments for minority clients—especially immigrants—case conceptualization and treatment must both be adapted. Clinical behavior analysis, in-cluding Acceptance and Commitment Therapy (ACT), allows for individualized assessment and treatment in such cases. ACT’s focus on defusion and valuing fit parti-cularly well into issues of cross-culture problems. Thus, a case study of ACT conducted with an Asian-Indian immigrant to the U.S. is presented. Specific adaptations of clinical work are discussed, along with treatment process and outcome results. Results indicate that ACT was useful. The need for replication and controlled studies is discussed.
Trends in spring snowpack over a half-century of climate warming in California, USA

Linear trends in 1 April snow water equivalent (SWE) in California, USA, are determined from a dense network of observations over the period 1950–2002. These trends are compared to concurrent time series of precipitation and temperature and Pacific Ocean climate indices. We find increased winter temperatures have accompanied both decreasing and increasing SWE trends, resulting in a weak overall negative trend in spring SWE. The spatial distribution of SWE trend is dependent on both latitude and elevation. Increases in both precipitation and temperature have led to increases in SWE at high elevations in southern Sierra Nevada and decreases at lower elevations. Increased temperature and decreased precipitation are associated with SWE loss in northern California. Trends in SWE can partially be attributed to shifts in Pacific Ocean climate indices.
The sequence effect in de novo Parkinson's disease.

Progressive slowness in speed or progressive decrease in amplitude of repetitive movements is unique in Parkinson’s disease (PD).1,2 It is referred to as the sequence effect (SE).3,4 Until now, it was well-demonstrated in only advanced PD.1–3 The SE might also be observed in drug-naive PD because the SE is a feature of bradykinesia, although measuring the SE has not been documented. Indeed, the SE might be difficult to identify in the drug-naive, early stage of PD because the SE might be too mild to detect. The characteristics of the repetitive movements in drug-naive PD might differ from that in advanced PD since the pattern of cerebral excitability is dissimilar between drug-naive and advanced PD5,6 and medication affects cortical plasticity in PD.7,8 With a computer-based, modified Purdue pegboard test, we reported that we measured the SE in advanced PD.3 At that time, we also conducted similar research with drug-naive PD, but we did not complete the study due to difficulty in recruiting drug-naive PD patients. Although we did not complete the study with de novo PD, we were able to see whether the SE could be measured in drug-naive PD.
Evidence of reduced resting blood flow in viable myocardial regions with chronic asynergy.

OBJECTIVES We tested the hypothesis in patients (n = 24) with ischemic heart disease that chronic contractile dysfunction occurs in myocardial regions with true reduction in rest blood flow. BACKGROUND Whether viable myocardial regions with chronic contractile dysfunction have true reduction in rest myocardial blood flow is controversial. METHODS Positron emission tomography (PET) 13N-ammonia was used to measure myocardial blood flow in combination with 18F-fluorodeoxyglucose (18FDG) to assess myocardial viability. Viability also was assessed by dobutamine echo and recovery of function after coronary artery bypass grafting (CABG). Segments (n = 252) were selected based on PET measured reduced resting blood flow and rest asynergy on echo. RESULTS Regional myocardial viability was present in 20 of 23 patients by PET, 13 of 23 by dobutamine echo and 10 of 11 by postrevascularization criteria. Rest blood flow in normal regions was 1.14 ± 0.52 ml/min/g and by definition exceeded (p < 0.005) that in both viable (0.48 ± 0.15; n = 8 patients) and nonviable (0.45 ± 0.14; n = 8 patients) regions (post-CABG criteria), which did not differ. Correction of rest myocardial blood flow in viable asynergic segments, only, for fibrosis and incomplete tracer recovery raised the level to 0.67 ± 0.21 (p < 0.005 vs. normal). Finally, evidence of both stunning (rest asynergy with normal flow) and hibernation was present in 15 of 23 (65%) patients. CONCLUSIONS Reduced rest blood flow in viable myocardial regions with chronic asynergy is common and cannot be accounted for by partial volume effect. Thus, hypotheses concerning physiologic mechanisms underlying chronic contractile dysfunction should consider the role played by chronic reduction of basal myocardial blood flow.
Controlling factors in hemofiltration

Abstract Ultrafiltration of bovine plasma and blood (hemofiltration) was performed in a dual-parallelmembrane test device over a wide range of hematocrits (0–85%), plasma protein concentrations (3–20 gm%), channel heights (0.022–0.073 cm) and flow rates. The plasma ultrafiltration data was used to determine film theory equation constants by regression techniques similar to that which had been done by others in the past. The ratios of hemofiltration to plasma ultrafiltration rates were then correlated by an independent analytical function of hematocrit, total protein concentration, and the superficial wall shear rate. The filtration flux ratio has a Fricke equation limit at low shear rates which would be below unity while a maximum filtration flux ratio greater than one was observed (and correlated) at high shear rates with hematocrits below 42%. The form of the hemofiltration correlation was also applied to previously published augmentation data in a pure shear field without plasma proteins. The design ramifications of the correlation include the determination of when addition augmentation methods are needed. The combination of both plasma ultrafiltration and hemofiltration correlations show how each variable affects and controls hemofiltration. The correlations are for small percentages of the incoming flow being filtered. For large flow fractions being filtered the correlations would have to be integrated along the axial length combined with mass balances. The hemofiltration equations can yield slightly lower fluxes at the lowest channel heights and slightly higher fluxes for the larger channel heights, presumably due to the Fahraeus—Lindqvist effect. The channel heights and shear rates utilized included conditions where this effect should be considerable as well as conditions where it should not be present. The regression techniques were applied to all the data.
Fossil pigments in paleoecology and paleolimnology

Abstract For the past several decades scientists have been examining the nature of sedimentary chlorophylls and carotenoids from freshwater lakes for their value in paleoecology and paleolimnology. Unaltered chlorophyll molecules are rarely preserved for long periods, but the pheo-derivatives and chlorophyllides are common throughout lake sedimentary columns. Carotenoids tend to preserve largely unaltered from their conditions in living plant membranes, but degrade quickly to colorless derivatives when oxidized. Measurements of sedimentary pigment concentrations, ratios of chlorophyll derivatives to carotenoids and diversity, especially as regards prokaryote carotenoids, are most commonly published. This paper assesses the value of using sedimentary pigment data to provide paleoecological information on lake evolution and changing patterns of aquatic primary productivity. Factors that promote pigment preservation are contrasted to those that alter and cause destruction of organic molecules. The value of fossil pigments is considered in ascertaining the sources of organic matter to sediments and for providing clues to the changing diversity of aquatic flora, both rooted and planktonic. Consideration is given to recent investigations that have sought information from sedimentary pigments on the onset and intensity of cultural eutrophication, both in individual lakes and on a regional basis, and in the monitoring of progress toward lake restoration. A special case is made for the value of sampling meromictic lakes. In addition, this review provides information on the limitations of the sampling procedures, laboratory techniques, and interpretation of results, Discussion is made of the most valuable and easily obtainable data that can provide reliable, comparable and reproducible results. Special consideration is given to the value of the pigment data in supplementing additional paleoecological indicators such as sedimentary pollen grains, zooplankton, and various other sedimentary bio- and geochemical products.
A study of recent classification algorithms and a novel approach for EEG data classification

This paper analyzes the application of different classification techniques for Electroencephalography (EEG) signals. Fuzzy Functions Support Vector Classifier (FFSVC), Improved Fuzzy Functions Support Vector Classifier (IFFSVC) and a novel hybrid technique that has been designed utilizing Particle Swarm Optimization and Radial Basis Function Networks (PSO-RBFN) have been studied. The classification performance of the techniques is compared on the same standard datasets that are publicly available and used by many Brain Computer Interface (BCI) researchers. Results show that proposed classifiers might reach the classification performance of state of the art classifiers and might be used as alternative techniques in the classification applications of EEG signals.
The role of Ghanaian immigrant associations in Toronto, Canada

Using information collected in a questionnaire survey, this article investigates the role of Ghanaian immigrant associations in Toronto to illustrate how a group of recent African immigrants organi...
Pulmonary macrophages are attracted to inhaled particles through complement activation.

Pulmonary macrophages play a central role in clearing inhaled particles from the lung. Previously, we showed that inhaled asbestos fibers activate complement-dependent chemotactic factors on alveolar surfaces to facilitate macrophage recruitment to sites of fiber deposition. In the studies presented here, we have tested a variety of inorganic particles for complement activation in vitro and correlated these data with results on particle-induced macrophage accumulation in vivo. We found that significant chemotactic activity was activated in rat serum and concentrated lavaged proteins by chrysotile and crocidolite asbestos, iron-coated chrysotile asbestos, fiberglass, and wollastonite fibers, as well as by carbonyl iron and zymosan particles. Ash from the Mt. St. Helens volcano did not induce chemotactic activity in either the serum or lavaged proteins.Rats were exposed to brief aerosols of each of the particles listed above (except zymosan). All the particle types studied were deposited primarily at first ...
Effects of vitamin A and β-carotene on plasma progesterone and uterine protein secretions in gilts

Abstract Twenty-four gilts detected in estrus were fed a barley-soybean meal diet which was essentially free of vitamin A and β-carotene. At the second estrus, gilts were randomly assigned to be fed daily the same basal control diet (CON), CON + 8200 IU vitamin A in the diet (VIT), CON + 4100 IU vitamin A + 8.2 mg β-carotene in the diet (CAR), or VIT + 16.4 mg β-carotene injected intramuscularly every other day (INJ). All gilts were sham-bred at the third estrus (day 0). On day 15, uterine secretions were flushed and uterine protein fractions were quantified after sequential chromatographic separations on Sephadex G-200 and G-50. Acid phosphatase activity in uterine flushings was measured also. Results showed nonsignificant treatment differences in the number of corpora lutea, ovarian weight, length of the estrous cycle and concentrations of plasma progesterone on days 0, 3, 6, 9, 12 and 15. The amount of total secretory protein was not different among treatment groups. However, CON had the lowest quantity of serum-like proteins and uterine-specific proteins and in the total and specific acid phosphatase activities. Group INJ tended to have the highest amount of each uterine protein fraction examined. Thus, deficiencies in vitamin A and β-carotene decreased certain uterine protein components while injected β-carotene tended to have an opposite effect. Such differences in uterine proteins may influence embryonic survival in pigs.
Acidosis blocks CCAAT/enhancer-binding protein homologous protein (CHOP)- and c-Jun-mediated induction of p53-upregulated mediator of apoptosis (PUMA) during amino acid starvation

Cancer cells must avoid succumbing to a variety of noxious conditions within their surroundings. Acidosis is one such prominent feature of the tumor microenvironment that surprisingly promotes tumor survival and progression. We recently reported that acidosis prevents apoptosis of starved or stressed lymphoma cells through regulation of several Bcl-2 family members (Ryder et al., JBC, 2012). Mechanistic studies in that work focused on the acid-mediated upregulation of anti-apoptotic Bcl-2 and Bcl-xL, while additionally showing inhibition of glutamine starvation-induced expression of pro-apoptotic PUMA by acidosis. Herein we report that amino acid (AA) starvation elevates PUMA, an effect that is blocked by extracellular acidity. Knockdown studies confirm that PUMA induction during AA starvation requires expression of both CHOP and c-Jun. Interestingly, acidosis strongly attenuates AA starvation-mediated c-Jun expression, which correlates with PUMA repression. As c-Jun exerts a tumor suppressive function in this and other contexts, its inhibition by acidosis has broader implications for survival of cancer cells in the acidic tumor milieu.
Narrow optical waveguides and instabilities induced in liquids

Self-trapped light beams having a 4μ diameter, a power density ⩾ 4GW/cm2, and a 0.5 nsec duration are observed in liquids. Instability effects, saturation in stimulated scattering processes, and the origin of the intensity-dependent refractive index are discussed.
Listeners' Response to Music as a Function of Personality Type

The purpose of this study was to examine listener response to music as a function of the personality variables measured by the Myers-Briggs Type Indicator (MBTI). Undergraduate nonmusic majors (N =...
Locally Derived Clinical Practice Guidelines Using a Decision Analysis Model

As health-care providers continually are faced with the need to identify the most cost-effective modalities when initiating therapy among many therapeutic options, standardized clinical guidelines become the foundation for decision making. This article discusses how decision analysis can be useful in the formulation of locally derived clinical practice guidelines. The following is an example of using decision analysis to evaluate data gathered within the institution, supplemented by peer-reviewed literature, to choose the most cost-effective agent in the treatment of chemotherapy-induced nausea and vomiting at the authors' institution.
Charge fluctuations between CuO2 layers in high-temperature superconductors.

A simple model based on the phase transition between a Bose liquid and a Fermi gas is presented. We show that under certain assumptions the long-range (distance greater than 3 \AA{}) Coulomb forces favor charge fluctuations between neighboring Cu${\mathrm{O}}_{2}$ layers in high-temperature superconductors, provided that the number $n$ of Cu${\mathrm{O}}_{2}$ layers within a unit cell is 2 or greater (with the convention that $n=1$ for La 2:1:4 and $n=2$ for Y 1:2:3, etc.). Qualitative discussion of the variation of ${T}_{c}$ on $n$, and on the doping parameter, is given.
On the Navier-Stokes initial value problem. I

Abstract : The initial value problem for the nonstationary Navier-Stokes equation is considered. New results were obtained with the aid of various methods from modern functional analysis. The existence of unique and global (in time) solutions for 2-dimensional flows as well as the existence of unique and local (in time) solutions for 3-dimensional flows was established. In most of these works the word solution was interpreted in a generalized sense. The purpose is to deduce such existence theorems for 3-dimensional flows through a Hilbert space approach, making use of the theory of fractional powers of operators and the theory of semi-groups of operators. (Author)
Computerized analysis of tissue density effect on missed cancer detection in digital mammography

Abstract This paper presents a study of the analysis of breast density in missed cancer cases and the effect of tissue density on caner detection. A total of 100 missed cancer cases were collected. The breast density tissue was segmented with a statistical-based method. A set of tests was then applied to examine: (1) the differences in density between the mammograms at the detected stage and that at missed stage; (2) the density difference between the cancerous mammograms and their contra-lateral normal mammograms in the missed cancer cases; (3) the effect of breast density on CAD cancer detection. The results demonstrate that breast density is an important factor affecting not only radiologist's reading but also CAD performance. In order to improve early detection of breast cancer, a special effort should be directed to the high dense breast cases in CAD system design.
Nuclear disruptions in the stratosphere

The Authors report some exemples of nuclear disruptions obtained in very sensitive photographic plates in the stratosphere through the use of free balloons.
Sensory Characteristics of Grain Sorghum Hybrids with Potential for Use in Human Food

ABSTRACT Descriptive sensory characteristics were measured for porridges made from flour samples collected from the 1996 Kansas feed grain sorghum performance tests and from commercial food grain sorghum samples. Totals of eight and 11 sensory attributes characterized the feed grain and food grain samples, respectively. Two screenings provided descriptive sensory data for univariate and multivariate analyses. Four feed grain samples from the performance tests and seven food grain samples were identified as low in astringency and bitterness; six of these were used in 100% sorghum flour muffins to determine consumer acceptability. Flavor acceptability of muffins was perceived as equal, and appearance was an important factor for acceptance. Optimization of all sensory attributes for each specific product is needed to increase acceptability of grain sorghum in consumer products.
Probing biological systems with near-field optics

The imaging characteristics of cantilevered NSOM probes operating in a tapping-mode feedback arrangement are discussed and compared to conventional tips employing the shear-force feedback method. Images form a wide range of samples are presented to demonstrate the surface tracking capabilities over both high and low topology samples, in addition to the low fluorescence detection limits possible utilizing the new tips. The results show that the cantilevered tip operating in a tapping-mode arrangement offers enhanced force imaging of the sample topology without compromising the low detection limits or high spatial resolution of the NSOM fluorescence images. The examples discussed here indicate that the new design will be particularly useful for applications involving biological samples that frequently exhibit complex surface topologies.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Education Level and Stability As It Relates to Early Childhood Classroom Quality: A Survey of Early Childhood Program Directors and Teachers

The field of early care and education is continually seeking to determine factors that contribute to the overall quality of the education for young children. Individual characteristics of teachers, including education level, have been associated with classroom quality. Program demographics, including turnover rate for teachers, also have had varying associations with levels of quality. The current study used data from teachers and directors participating in the North Carolina Rated License process to explore relationships between education levels for teachers and directors with levels of classroom quality, and between stability of position for teachers and classroom quality scores. Teacher education level and stability (i.e., consistently working with the same age group) were positively related to classroom quality scores. Higher education levels for center directors and center director enrollment in a college course also were associated with higher quality scores for their programs. Results suggest that, in addition to teacher education, other factors within child care centers are critical to the quality of care that teachers provide.
Towards a platform PBPK model to characterize the plasma and tissue disposition of monoclonal antibodies in preclinical species and human

The objectives of the following investigation were (1) development of a physiologically based pharmacokinetic (PBPK) model capable of characterizing the plasma and tissue pharmacokinetics (PK) of nonspecific or antigen specific monoclonal antibodies (mAbs) in wild type, FcRn knockout, tumor bearing and non tumor bearing mice and (2) evaluation of the scale up potential of the model by characterizing the mouse, rat, monkey and human plasma PK of mAbs, simultaneously. A PBPK model containing 15 tissues, a carcass and a tumor compartment was developed by modifying/augmenting previously published PBPK models. Each tissue compartment was subdivided into plasma, blood cell, endothelial, interstitial and cellular sub-compartments. Each tissue was connected through blood and lymph flow to the systemic circulation. Lymph flow was set to a value 500 times lower than plasma flow and vascular reflection coefficients for each tissue were adjusted according to their vascular pore size. In each tissue endothelial space, mAb entered via pinocytosis and the interaction of FcRn with mAb was described by on and off rates. FcRn bound mAb was recycled and unbound mAb was eliminated by a first order process (K deg ). The PBPK model was simultaneously fit to the following datasets to estimate four system parameters: (1) plasma and tissue PK of nonspecific mAb in wild type mouse with or without simultaneous intravenous immunoglobulin (IVIG) administration, (2) plasma and tissue PK of nonspecific mAb in FcRn knockout mouse, (3) plasma and tissue PK of nonspecific mAb in tumor bearing mouse, (4) plasma and tissue PK of tumor antigen specific mAb in tumor bearing mouse, and (5) plasma PK of mAb in rat, monkey and human. The model was able to characterize all the datasets reasonably well with a common set of parameters. The estimated value of the four system parameters i.e. FcRn concentration (FcRn), rate of pinocytosis per unit endosomal space (CL up ), K deg and the proportionality constant (C_LNLF) between the rate at which antibody transfers from the lymph node compartment to the blood compartment and the plasma flow of the given species, were found to be 4.98E−05 M (CV% = 11.1), 3.66E−02 l/h/l (%CV = 3.48), 42.9 1/h (%CV = 15.7) and 9.1 (CV% > 50). Thus, a platform PBPK model has been developed that can not only simultaneously characterize mAb disposition data obtained from various previously published mouse PBPK models but is also capable of characterizing mAb disposition in various preclinical species and human.
Normalization of nitric oxide production corrects arterial vasodilation and hyperdynamic circulation in cirrhotic rats

Abstract Background & Aims Recent studies suggest that production of nitric oxide is increased in cirrhosis. This study determines to what extent this increased production contributes to arterial vasodilation and hyperdynamic circulation in cirrhosis. Methods Mean arterial pressure (MAP), cardiac index, and Systemic vascular resistance (SVR) were determined in cirrhotic rats with ascites undergoing long-term treatment with different doses of the NO synthesis inhibitor N G -nitro-l-arginine methyl ester (l-NAME) (3 mg or 0.5 mg. kg −1 · day −1 ). Untreated cirrhotic rats with ascites and controls were also studied. The vascular production of NO was estimated by the aortic concentration of guanosine 3′,5′-cyclic monophosphate (cGMP). Results Untreated cirrhotic rats had significantly lower MAP and SVR and higher cardiac index and aortic cGMP concentration than controls. When administrated to cirrhotic rats, an l-NAME dose of 3 mg · kg −1 · day −1 induced a reduction of cGMP concentration less than normal levels. In these rats, MAP and SVR increased to greater than and cardiac index decreased to less than values in controls. By contrast, cirrhotic rats treated with 0.5 mg · kg −1 · day −1 l-NAME had similar aortic cGMP concentrations as controls, suggesting a normalization of NO production. This was associated with a normalization of MAP, cardiac index, and SVR and a reduction in the elevated plasma renin activity and vasopressin concentration. Conclusions Normalization of vascular NO production corrects systemic hemodynamic abnormalities in cirrhotic rats with ascites.
Electron microscopic observations on transitional epithelium of the mouse urinary bladder

Previously, transitional epithelium was thought to consist of two cell types. Now, on the basis of fine structure, three distinct types of cells can be identified in the transitional epithelium of mouse urinary bladder, and each type corresponds to a separate cell layer. Thus, a layer of surface cells, a layer of intermediate cells and a layer of basal cells can be recognized. Surface cells are characterized by the presence of an apical layer of fine fibrils, some dense spherical granules about twice the size of the mitochondria, and many large vesicles. The vesicles are of two types: (1) round vesicles which may be involved in pinocytosis because thorium dioxide injected into the bladder lumen can subsequently be found in these vesicles; (2) compressed vesicles which do not take up thorium dioxide crystals but perhaps function as part of a dynamic urine barrier by carrying fluids from the cytoplasm to the cell surface. Cells of the intermediate layer have compressed vesicles, granules, and some large membranous whorls. The basal cells are devoid of these specialized cytoplasmic structures. Golgi apparatus, mitochondria and agranular endoplasmic reticulum are present in the cells of all three layers.
Cloning and transcription analysis of the entire glycerol utilization (gylABX) operon of Streptomyces coelicolor A3(2) and identification of a closely associated transcription unit.

The entire glycerol utilization (gylABX) operon of Streptomyces coelicolor A3(2) was cloned and its transcriptional organization and regulation was analyzed by Northern blotting, S1 nuclease mapping and transcriptional fusions. Transcription of the operon is glycerol-inducible and glucose-repressible; gylA (presumptively encoding glycerol kinase), gylB (encoding sn-glycerol-3-phosphate dehydrogenase) and gylX (a non-essential 1.1 kb sequence) are transcribed consecutively to give a 5.4 kb mRNA. Two alternative transcription termination or gyl mRNA processing sites are located within the operon; one (a discrete site) lies between gylB and gylX and the other (a heterogeneous site) positioned 3 kb into the operon, may correspond to the gylA-gylB intercistronic region. A 0.9 kb glycerol-inducible transcription unit is located immediately upstream of gylABX. Transcriptional fusion studies employing an attP site-deleted phage vector provided complementary evidence for the organization of the operon.
Changes in brain GnRH associated with photorefractoriness in house sparrows (Passer domesticus).

Temperate zone birds terminate reproduction when they become photorefractory. In many species, refractoriness is "absolue" in that gonadal regression occurs before day length declines, and individuals are reproductively unresponsive even to continuous light. Based on studies of a few species, this form of refractioness appears to be associated with a reduction (compared with breeding and/or photosensitive birds) in numbers of hypothalamic cells and fibers that are immunoreactive for gonadotropin releasing hormone GnRH). Some species display "relative" refractoriness, in that day length must decline before gonadal regression occurs, and individuals never lose the capacity to respond to very long days. A few reports suggest that GnRH levels in the brain do not change in relatively refractory birds. House sparrows (Passer domesticus) regress their gonads sooner when day length declines during summer than they do if photoperiod is not permitted to decline after the summer solstice (i. e., they appear to be "relatively" refractory). However, if held on long days they eventually regress the gonads despite no decline in photoperiod (they appear to be "absolutely" refractory). In this experiment, we tested whether gonadal regression was associated with changes in hypothalamic GnRH in adult male house sparrows. We used immunocytochemistry (primary anti-body sensitive to both forms of avian GnRH) to compare the distribution and number of GnRH-immunoreactive cells, and fibers among reproductivity active individuals on long days, "absolutely" refractory individuals on long days, and presumably "relatively" refractory individuals induced to regress by shortened days. Similar reductions in ir-GnRH cell number and cell size occurred in both groups of refractory birds compared with birds still in breeding condition. Gonadal regression also was correlated with reduced staining intensity of cell bodies and reduced fiber staining, but these reductions were somewhat more pronounced in the "absolutely" than the "relatively" refractory birds. We discuss these results in light of other studies of avian GnRH changes with reproductive stage. Our results are consistent with the idea that house sparrows become absolutely refractory, regardless of whether exposed to a decline in photoperiod. However, the results also suggest that relative refractoriness may induce gonadal regression through a cessation of GnRH secretion, whereas absolute refractoriness involves down-regulation of peptide production as well.
The Response of Swamp Sparrows To Acoustically Distinct Song Types

Male and femal swamp sparrows (Melospiza georgiana) were tested for differential reaction to four acoustically distinct swamp sparrow song types. We tested males by playing bouts of single song types from speakers placed on male territories. Males gave the same kinds of aggressive responses to each of the four song types, and there were no quantitative differences in the strengths of the responses to the different types. In the experiments with females, we played songs to captive female swamp sparrows previously treated with estradiol, and measured response in terms of copulation solicitation display. Females displayed in response to all four song types, and again there were no quantitative differences in the strength of response to the different types. We conclude that different swamp sparrow song types do not convey different messages to either male or female listeners. Although the identity of the particular song type presented was unimportant, the number of types presented was important, at least to females. Females responded more strongly overall to bouts of four song types than to bouts of single song types. This result occurred because females habituated to the repeated presentation of a single song type, and showed a recovery in response when song types were switched. We conclude that the ability to sing multiple song types may aid males in stimulating females to come into reproductive condition and then copulate.
A low-power active inductor with improved Q-factor and its application to phase shifter

This letter presents a low-power single-ended active inductor with its Q-factor enhanced by feedback. Without sacrificing the self-resonance frequency and increasing the DC power consumption of the main circuit, the feedback transistor introduces a negative resistance; therefore, high Q-factors can be achieved in a wide operating frequency range. The proposed inductor was designed in a 0.13 μm CMOS process and simulated using Cadence Spectre. The active area is ~4 μm × 5 μm. With ~0.1 mW power consumption, the designed active inductor shows a 17 GHz maximum self-resonance frequency and a 1---8 GHz peak-Q operating frequency range. Using this active inductor, a 3-bit digitally-controlled phase shifter was designed. The phase shifter can provide a phase shift range larger than 180° from 1.5 to 4 GHz and a return loss better than 10 dB.
Genesis and role of wear debris in sliding wear of ceramics

Abstract We survey the formation, appearance and properties of wear debris in ceramics and their influence on the wear of these materials. These differ from those of metals, in accord with the different mechanical and chemical properties of ceramics. Ceramics, in contrast to metals, do not form hard and cohesive mechanically alloyed surface layers. The formation of wear debris is very sensitive to the environment (humidity), it occurs mostly by fracture on different scales: microfracture at low loads, grain boundary fatigue at intermediate loads and macroscopic fracture at high loads. The wear debris that remain in the wear track are ground to a very fine powder by continued rubbing. In dry ambient, this powder has low mechanical strength and has very little influence on wear. In humid ambient, the phenomena depend on the material. Tribochemical reactions of non-oxide ceramics form relatively large amounts of compact hydrated oxide. On oxide ceramics such as alumina and silica, interaction with water vapor has been observed to create thin hydroxide layers, which can act as lubricants, as observed on alumina. The tribochemical layers often form rolls on the surface. These rolls do not act as ‘rolling bearings’ and do not reduce friction or wear. Ambient humidity causes adhesion between the wear debris which are compacted into layers that have sufficient cohesion to reduce wear by distributing the contact stresses. In water and some aqueous solutions, silicon nitride and silicon carbide dissolve in water and do not form wear debris.