cssi/SciSciGPT-SciSciNet huggingface dataset:
TU‐E(SAM)‐211‐02: Role of the Medical Physicist in Clinical Implementation of Breast Tomosynthesis

FDA recently approved Hologic Selenia Dimensions Tomosynthesis system for 3 dimensional breast imaging. Many new systems will be installed in the near future. To properly support the implementation of this new modality, clinical physicists need to understand unique operation conditions of the tomosynthesis system, shielding requirements, factors affecting image quality and patient dose, sources of image artifacts, in addition to knowing the basic principles of tomosynthesisimage acquisition and reconstruction. This talk will focus on the implementation and acceptance test of Hologic Selenia Dimensions tomosynthesis system. The operation modes, typical acquisition parameters, x‐ray beam characteristics, system performance in terms of image quality and patient dose will be described. The impact of unique imaging acquisition parameters on shielding requirements will be discussed. The acceptance tests which are unique to the tomo modes will be illustrated. Learning objectives: 1. Understand the typical operation modes of Hologic tomo system and image acquisition parameter range. 2. Understand the achievable system performance of Hologic tomo system in terms of image quality and patient dose. 3. Understand the impact of the unique tomo image acquisition parameters on room shielding requirement 4. Understand major factors influencing the image quality and patient dose 5. Know how to perform the acceptance test.
MRI T2 hypointensity of the dentate nucleus is related to ambulatory impairment in multiple sclerosis

Abstract Objectives MRI T2 hypointensity in multiple sclerosis (MS) gray matter, suggesting iron deposition, is associated with physical disability, disease course, lesion load, and brain atrophy. Ambulatory dysfunction limits quality of life; however correlation with conventional MRI remains poor. Methods Normalized intensity on T2-weighted images was obtained in the basal ganglia, thalamus, red nucleus, and dentate nucleus in 47 MS patients and 15 healthy controls. Brain T1-hypointense and FLAIR-hyperintense lesion volume, third ventricle width, brain parenchymal fraction and timed 25 foot walk (T25FW) were measured in the MS group. Results T2 hypointensity was present throughout gray matter in MS vs. controls (all p r =−0.355, p =0.007) and was also the best MRI correlate of physical disability (EDSS) score in regression modeling ( r =−0.463, R 2 =0.223, p =0.004). Conclusions T2 hypointensity is present in subcortical gray matter nuclei in patients with MS vs. normal controls. Dentate nucleus T2 hypointensity is independently related to ambulatory impairment and disability, accounting for more variance than conventional lesion and atrophy measures. This study adds more weight to the notion that T2 hypointensity is a clinically relevant marker of tissue damage in MS.
SU‐FF‐T‐58: Accuracy in Prostate Delineation From CBCT Fo RT Planning

Purpose: Evaluate the accuracy in prostate contours from CBCT scans for RT planning. Method and Materials: One FBCT and five CBCT scans are taken per each of five prostate cancer patients. The prostate is delineated on all scans three times by each of three observers. The intersection and union contour of each scan by each observer are computed. The prostate contours from the FBCT scan are mapped onto the daily CBCT scans. Three margin strategies (3 or 5 mm expansions about the intersection and 2 mm expansions about the union of the prostate contours) are used to create three PTV's. The three PTV's from each CBCT are used to create 3D plans. Geometrical overlap (FBCT contours to CBCT contours), FBCT prostate contour coverage by the CBCT plans, rectal and bladder dose indices are evaluated on each CBCT.Results: The average overlap of the FBCT prostate with CBCT PTV's (with 2 to 5 mm margins) range from 92% to 98% with average coverage of the FBCT prostate contours of 93% to 98% of the prescription dose. FBCT prostate contours may extend in some regions up to 5 mm at the base and apex of the unexpanded CBCT prostate for some cases (possibly due to interfraction prostate deformation). However, 3D plans using PTV's resulting from 3mm (L/R and A/P) and 5mm (S/I) margin expansions cover the FBCT prostate contours with more than 95% of the dose. Conclusion: 3DCRT, CBCT‐based planning of localized prostate carcinoma should include a 2–5 mm expansion of the prostate contour to correct for contouring uncertainties, based on comparisons to FBCT‐based planning. This result includes the influence of transient prostate deformations between imaging sessions and CBCTimaging uncertainties, but does not include intra‐ and inter‐fractional motion considerations.
Passive transfer of immunity to neonatal calves against the metacestodes of Taenia saginata.

Abstract Passive transfer of immunity to neonatal calves against Taenia saginata was examined. Immune serum immunoglobulins were obtained from cattle inoculated orally with eggs of T. saginata , and from an animal which had been injected intramuscularly with eggs and activated oncospheres of the parasite. Immune colostral immunoglobulins were obtained by local injection of the mammary gland of a preparturient cow using activated oncospheres of T. saginata as antigen. Newborn calves fed the immune serum or colostral immunoglobulins were significantly protected against infection with T. saginata . In addition, more than 80% of the metacestodes in the protected calves showed evidence of degeneration, while only 34 and 27% of the metacestodes showed evidence of degeneration in those animals receiving “normal” control serum and “normal” control colostral immunoglobulins, respectively.
Numerical calculation of induction times for crystallization of glasses

Abstract The coupled rate equations of classical nucleation theory are solved numirically, and the induction time needed to reach steady state nucleation is calculated. Although the results do not differ significantly from the value obtained from the Kashchiev solution of the Zeldovich equation, the functional dependence of the induction times on the thermodynamic parameters is different. It is shown that, at least in the case of crystallization from glassy melts, nucleation occurs only at undercooling corresponding to small critical clusters such that numerical calculations are possible and convenient.
John Aubrey, F.R.S., John Lydall, and science at Commonwealth Oxford.

CONSIDERING all the manuscript material which has been scrutinized in the search for evidence bearing upon the origins and early character of the Royal Society, it is mildly surprising that the correspondence of one of its earliest and most enthusiastic members, John Aubrey, should have lain neglected for so long. Among his unpublished papers in the Bodleian Library is a series of letters written to him from Commonwealth Oxford by his friend and scientific mentor, John Lydall, a Fellow of Trinity College. The correspondence is of interest, both because it throws light upon the somewhat shadowy history of the Oxford group which later participated in founding the Royal Society, and because it demonstrates that the Oxford contingent was interested in a range of problems no less empirical, mechanical, and mathematical, than its London counterpart at Gresham College. This in turn bears upon some conflicting views of the roots and essential character of the Society.
Conformational change in thrombospondin induced by removal of bound Ca2+ A spin label approach

The effect of removal of Ca2+ bound to thrombospondin (TSP) on the protein structure in solution has been investigated using ESR spin-label techniques. A maleimide spin label was selectively attached to the free thiol group presumably near the carboxyl-terminal domain in which Ca2+-binding sites are situated. The ESR spectra of spin-labeled TSP showed that the bound label undergoes a relatively fast rotational motion with an effective rotational correlation time in the nanosecond time regimes. Removal of bound Ca2+ in TSP by dialyzing spin-labeled TSP from a Ca2+-containing buffer into an EDTA-containing buffer resulted in an increase in the mobility of the bound label by a factor of 2.3. The data suggest that EDTA chelation of bound Ca2+ in TSP induces a conformational change of TSP at least near the site of spin labeling.
Coronary heart disease and hormone replacement therapy after the menopause.

The discordance in coronary heart disease (CHD) outcome between randomized, controlled trials and observational studies of hormone replacement therapy (HRT) is likely the result of the dissimilar cohorts studied. This observation led to the formation of the timing hypothesis that benefits and risks of HRT depend upon age of HRT initiation and/or time of HRT initiation in relation to menopause. This hypothesis has been supported with data from large, randomized, controlled trials that have studied HRT and selective estrogen receptor modulators (SERMs) in the prevention of CHD. Initiation of HRT in women <60 years of age and/or within 10 years of menopause reduces both CHD and total mortality; SERMs have been shown to reduce CHD in women <60 years. What has become clear from the cumulated literature is that in young postmenopausal women who initiate HRT in close proximity to menopause, the adverse effects of HRT are rare and no greater than those of other commonly used pharmacological agents and that the pr...
Children's alcohol cognitions prior to drinking onset: Discrepant patterns from implicit and explicit measures.

Prior to drinking onset, children report stronger negative versus positive beliefs on self-report alcohol expectancy questionnaires, with some attenuation of this negativity as they transition into adolescence. Traditional alcohol expectancy assessments, however, capture endorsement of deliberative propositions about drinking outcomes. Measurement of implicit alcohol associations may elucidate automatic evaluations, clarifying the role of nondeliberative cognition in the initiation of alcohol use among youth. Few studies have assessed implicit alcohol cognition among children and younger adolescents, with inconsistent findings regarding the nature of these automatic associations within and between age groups. Eighty-nine 3rd and 4th graders and 91 7th and 8th graders completed an alcohol expectancy measure and two unipolar alcohol Implicit Association Tests (IAT) measuring positive and negative alcohol associations independently. On the explicit measure older compared with younger participants rated positive drinking outcomes as more likely and negative outcomes as less likely. Older compared with younger students were also more neutral/moderate in their evaluations of positive drinking outcomes. On the IATs, scores for the full sample indicated negative alcohol associations, and Negative IAT scores were higher for older compared with younger participants. However, the valence of implicit alcohol associations was qualified by the order of explicit versus implicit assessment; for those who completed the IATs prior to the explicit expectancy measure, alcohol associations were positive. Findings replicate and extend prior research conducted with preonset youth. Implications regarding the role of automatic and controlled processes in drinking onset and directions for future work on children's alcohol cognition are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved). Language: en
Vinorelbine, doxorubicin, and prednisone in androgen-independent prostate cancer.

BACKGROUND. Ultimately, patients with metastatic prostate cancer progress on androgen ablation therapy. The investigation of new chemotherapeutic regimens for the treatment of androgen-independent prostate cancer (AIPC) is essential. The authors conducted a Phase II trial with vinorelbine, doxorubicin, and daily prednisone (NAP) to investigate the antitumor activity and palliative response of this regimen in patients with AIPC. METHODS. Forty-six patients entered this Phase II combination chemotherapy trial. Patients were treated with both vinorelbine and doxorubicin at doses of 20 mg/m2 on Days 1, 8, and 15 every 28 days and prednisone 5 mg twice daily. Endpoints included prostate-specific antigen (PSA) response and palliation, as measured by the Functional Assessment of Cancer Therapy-Prostate (FACT-P) instrument, the Brief Pain Inventory Scale, and a narcotic analgesic log. RESULTS. The median follow-up for all 46 patients was 13.4 months. Fifty-two percent of patients had impaired performance status at baseline. One responding patient remained on NAP and was progression-free at 11.5 months. Thirty-nine patients progressed, 3 patients died prior to response assessment, and 3 patients refused therapy. The median overall survival was 57 weeks (95% confidence interval [95% CI], 36–76 weeks), and the median time to disease progression was 17 weeks (range, 11–24 weeks). The PSA response among the 36 patients who completed 3 cycles of NAP was 42% (95% CI, 26–59%). There was a statistically significant improvement in quality of life measured both by the FACT-General instrument (P = .03) and the FACT-P instrument (P = .0006) over the 3 months compared with baseline measurements. Pain medicine use also improved: The median morphine equivalents among patients who were taking pain medications at the time of study enrollment showed a substantial decline after 1 cycle of treatment that was maintained. Pain (as assessed by the Brief Pain Inventory) improved compared with baseline pain at the 2nd-month assessment (worst pain, P = .08; least pain, P = .02; and average pain, P = .003). Overall, the regimen was tolerated well. The most common side effects were mild fatigue and gastrointestinal complaints (all of which were Grade 1 or 2 [according to Version 2.0 of the Expanded Common Toxicity Criteria]). Seventeen patients (37%) experienced Grade 3 or 4 neutropenia. Five patients (11%) developed a cardiac ejection fraction of <50% during treatment and had doxorubicin discontinued. No patients developed clinical congestive heart failure. CONCLUSIONS. The NAP combination produced substantive palliation and a moderate response rate in men with AIPC. Cancer 2006. © American Cancer Society.
Studies on the mechanism of glucocorticoid hormone induced alterations in rat thymic transcription--II. Partial purification and characterization of RNA polymerases II from hydrocortisone and control vehicle treated animals.

Abstract In experiments designed to study the mechanism of glucocorticoid hormone induced reductions in rat thymic transcription, adrenalectomized rats were injected with hydrocortisone (50 mg/kg) or control vehicle 12 h prior to sacrifice. Thymic nuclei were used to prepare soluble nuclear extracts containing RNA polymerase II. Nuclear extract RNA polymerases II were then partially purified (600-fold) on DEAE-Sephadex columns and characterized. The responses of partially purified thymic RNA polymerases II from rats treated in vivo with hydrocortisone or vehicle were similar to: pH, temperature, ionic strength, trypsin proteolysis, and inhibition by alpha-amanitin; however, RNA polymerase II from hydrocortisone treated animals was consistently reduced in activity compared to control RNA polymerase II. Determination of the apparent specific activities of peak RNA polymerase II fractions from DEAE-Sephadex columns suggested that the specific activity of RNA polymerase II from hydrocortisone treated animals was reduced compared to RNA polymerase II activity from control animals. The fact that both nuclear extract and partially purified RNA polymerases II from hydro-cortisone treated rats were reduced in activity when assayed in reconstituted transcriptive systems suggests a denatured, defective or modified RNA polymerase II molecule acting as a transcription inhibitor. Thermally denatured nucleoplasmic RNA polymerase II fractions were shown to interfere with transcription by native nucleoplasmic RNA polymerase II in vitro , but did not appear to inhibit transcription to the degree observed in vitro following in vivo hydrocortisone administration.
Keeping Abreast of Hypersexuality: A Video Game Character Content Analysis

This study examined male and female sexuality in video game characters. The top 20, best selling console (Microsoft Xbox, Sony PlayStation2, and Nintendo GameCube) video games from the U.S. market for fiscal year 2003 were content analyzed. The 60 video games yielded a total of 489 separate characters with an identifiable sex for coding. Chi-square analyses indicated that female characters (n = 70) were underrepresented in comparison to their male counterparts (n = 419) as hypothesized. In comparison to male characters, females were significantly more likely to be shown partially nude, featured with an unrealistic body image, and depicted wearing sexually revealing clothing and inappropriate attire as also predicted. Implications for these findings are discussed using social cognitive theory as a theoretical anchor.
Numerical Study of Nonreacting Gas Turbine Combustor Swirl Flow Using Reynolds Stress Model

This paper presents recent research on the use of a Reynolds stress turbulence model (RSTM) for three-dimensional flowfield simulation inside gas turbine combustors. It intends to show the motivations for using the RSTM in engine flow simulation, to present a further validation of the RSTM implementation in the KIVA code using the available experimental data, and to provide comparisons between RSTM and k-e turbulence model results for chemically nonreacting swirling flows. The results show that, for high-degree swirl flow, the RSTM can provide predictions in favorable agreement with the experimental data, and trial the RSTM predicts recirculations and high velocity gradients better than does the k-e turbulence model. The results also indicate that the choice of swirler has a significant influence on the structure of the combustor flowfield.
Effect of high temperature and dietary fat on performance of lactating cows

Abstract Two Latin squares balanced for carry-on effects were used for evaluation of productive performance of 12 Holstein cows fed high levels of fat under environmental temperatures: cool 15–24 C and hot 32.2 C, 60% relative humidity. The cows were fed 1.25 kg alfalfa-grass hay per 100 kg body weight and one of three concentrates: control (without added lipids), oil (10% soybean oil), or fat (10% hydrogenated vegetable fat, iodine value 48) replacing corn on a weight basis. Elevated temperature resulted in a marked depression in yield of milk and milk fat, SNF, and protein, of body weight, feed intake, rumen VFA, acetic:propionic ratio, and gross efficiency; water intake and rectal temperature increased. Significant ration effects were observed only in the case of FCM production, where the oil-fed cows excelled. Environmental effects were independent of ration effects, except in water intake, rumen total VFA, and acetic acid levels, where interactions were noted. Significant period effects from repeated exposures to heat stress were noted only in FCM yield, water consumption, and rumen propionate. The drastic environmental stress imposed in this study served to mask many of the anticipated ration effects.
A factor analysis of landscape pattern and structure metrics

Fifty-five metrics of landscape pattern and structure were calculated for 85 maps of land use and land cover. A multivariate factor analysis was used to identify the common axes (or dimensions) of pattern and structure which were measured by a reduced set of 26 metrics. The first six factors explained about 87% of the variation in the 26 landscape metrics. These factors were interpreted as composite measures of average patch compaction, overall image texture, average patch shape, patch perimeter-area scaling, number of attribute classes, and large-patch density-area scaling. We suggest that these factors can be represented in a simpler way by six univariate metrics - average perimeter-area ratio, contagion, standardized patch shape, patch perimeter-area scaling, number of attribute classes, and large-patch density-area scaling.
E2 nuclear resonance effect in pionic atoms

Abstract The quadrupole nuclear resonance effect in pionic atoms is considered, and the results of calculations for pionic atoms with distorted even-even nuclei are presented.
Calcium entry modulation and renal hemodynamics in the hypertensive kidney.

In the isolated perfused rat kidney, the superimposition of a number of calcium entry blockers (CEB) upon norepinephrine vasoconstriction prompts an increase in the glomerular filtration rate (GFR) to a level substantially greater than the original value. A similar acute GFR response to CEB is manifested in the intact anesthetized rat with the renal perfusion pressure remaining constant. This glomerular response to CEB is accentuated in isolated perfused kidneys from Dahl salt-sensitive (DS) rats as compared with kidneys from Dahl salt-resistant (DR) rats. The disparities between DS and DR kidney responses are further amplified in the DS rat kidney after a high NaCl intake and the development of hypertension by the DS rat. In addition, vasoconstrictor responses to BAY-K 8644, a calcium entry facilitator, are accentuated in DS rat kidneys, and even more so following a high NaCl intake or ‘chemical sympathectomy’ with 6-hydroxydopamine. These results suggest that subtle changes in vascular and glomerular calcium entry modulation may be the key determinants of altered renal hemodynamics in salt-dependent hypertension.
RADICAL CYSTECTOMY FOR PRIMARY NEUROENDOCRINE TUMORS OF THE BLADDER: THE UNIVERSITY OF SOUTHERN CALIFORNIA EXPERIENCE

ABSTRACT Purpose: Primary neuroendocrine tumors of the bladder are rare and they include small and large cell variants. We reviewed our experience with treating these tumors with radical cystectomy to evaluate their histopathological characteristics and clinical outcomes. Materials and Methods: From August 1971 to June 2004, 2,005 patients underwent radical cystectomy for primary bladder cancer at our institution, of whom 25 (1.2%) had neuroendocrine tumors of the bladder, including small cell carcinoma in 20 and large cell carcinoma in 5. Pure neuroendocrine-type histology was identified in 16 cases, including 1 with small and large cell features, while the remaining 9 had mixed histology, that is transitional cell carcinoma in 8 and adenocarcinoma in 1. Multi-agent chemotherapy was administered to 14 patients. Results: Median patient age was 68 years (range 40 to 82) and 19 patients were male (76%). A total of 19 patients (76%) had lymph node involvement, of whom 2 had small liver metastases found intraoperatively, while only 4 (16%) had organ confined tumors and 2 (8%) had extravesical, node negative disease. These tumors tended to have a flat, ulcerative gross appearance with lymphovascular invasion, carcinoma in situ and necrosis present microscopically. Median followup was 11.8 years (range 18 days to 15.1 years). Five-year overall and recurrence-free survival was 10% and 13%, respectively. There was no significant survival difference between small and large cell carcinoma. Mixed histologies tended to do better than pure neuroendocrine tumors, although this did not attain statistical significance (p = 0.064). Patients receiving multimodality therapy had significantly better overall (p = 0.051) and recurrence-free (p = 0.003) survival than those treated with cystectomy alone. Conclusions: Neuroendocrine tumors of the bladder usually present with advanced pathological stage and portend a poor prognosis. Adjuvant chemotherapy protocols may provide improved survival compared with cystectomy alone.
Seismic effects from major basin formations on the moon and Mercury

Grooved and hilly terrains occur at the antipode of major basins on the Moon (Imbrium, Orientale) and Mercury (Caloris). Such terrains may represent extensive landslides and surface disruption produced by impact-generatedP-waves and antipodal convergence of surface waves. Order-of-magnitude calculations for an Imbrium-size impact (1034 erg) on the Moon indicateP-wave-induced surface displacements of 10 m at the basin antipode that would arrive prior to secondary ejecta. Comparable surface waves would arrive subsequent to secondary ejecta impacts beyond 103 km and would increase in magnitude as they converge at the antipode. Other seismically induced surface features include: subdued, furrowed crater walls produced by landslides and concomitant secondary impacts; emplacement and leveling of light plains units owing to seismically induced ‘fluidization’ of slide material; knobby, pitted terrain around old basins from enhancement of seismic waves in ancient ejecta blankets; and perhaps the production and enhancement of deep-seated fractures that led to the concentration of farside lunar maria in the Apollo-Ingenii region.
Protocol for the successful treatment of venous ulcers

Venous ulcers affect up to 2.5 million patients per year in the United States. Although not usually fatal, these chronic wounds severely affect patients' quality of life because of impaired mobility and substantial loss of productivity. Although venous ulcers are typically small initially, they are often undertreated, progressing to larger ulcers that are associated with more serious complications requiring more complex treatments. In this report we detail the pathogenesis of venous ulcers together with potential complications, including exudate, erythema, cellulitis, dermatitis, pain, and possible malignancy. The clinician's regimen should always include a wide range of treatment modalities to ensure comprehensive care and effective wound closure. The treatment modalities and specific protocol for venous ulcers are discussed, and include topical dressings, antibiotics, debridement, compression therapy, and cellular therapy. These treatment modalities, in combination with early recognition and regular monitoring using digital photography and planimetry measurements, will ensure rapid healing and minimize complications and cost.
A multimodal speaker detection and tracking system for teleconferencing

A serious problem in both audio and video conferencing facilities available today is the difficulty in determining who is speaking among a large number of participants. There is a strong need for developing meeting room infrastructure and teleconference facilities that improve the sense of presence and participation experienced in remote meetings. We present a distributed multimodal tracking system that uses multiple cameras and microphones to automatically select the current speaker among multiple meeting participants. The system actively obtains and transmits video showing a good view of the selected speaker. The tracking system is integrated into a web-based video conferencing application that connects seven meeting rooms around the globe. An important part of designing such a system is to determine sensor placement and configuration through systematic experiments in the actual rooms where the system is deployed.
Associating conservation/production patterns in US farm policy with agricultural land-use in three Iowa, USA townships, 1933–2002

Agricultural policy objectives in developed nations include counteracting overproduction, increasing economic and social well-being, and environmental protection. Such policies, however, often work at cross-purposes. While vast financial resources have been invested in farm programs, little research connects historic trends in agricultural policy with land-use patterns in agricultural landscapes. We connect the legislative history of US farm bills with land-use decisions as observed on the historical agricultural landscape in three townships in Iowa, USA, 1933–2002. With a high proportion of agricultural land, increasing biofuels development, and high participation in federal conservation programs, Iowa presents an ideal case study to explore the relationship between policy and historical land use. Using data from the US Census of Agriculture and historical aerial photography, we conduct our analysis within a framework that identifies alternating eras of US farm policy in terms of legislative focus on conservation vs. production. We describe the impact of US farm policy on the following indicators: maize and soybean area, production, and productivity; hectares in idled land, pasture, and hay ground; and adoption of soil conservation practices. Patterns of agricultural and conservation land use support the idea of alternating conservation–production eras of US farm policy. Three important patterns emerge: (1) despite reductions in maize hectares that correspond with conservation-oriented policy eras, supply management policies have failed to control maize production due to increased productivity; (2) as pasture and hay hectares decline, government set-aside programs are increasingly important for perennial vegetation within agricultural landscapes; and (3) although soil conservation practices have generally increased as agricultural land use has intensified, persistent links between poor environmental quality and farm programs suggest that implementation alone will not achieve environmental quality goals. Environmental improvement likely requires a shift from policies focused on the quantity of commodities produced to policies focused on pattern and process of production in multifunctional agricultural landscapes, and we discuss how policies that promote extensification abroad might inform domestic agricultural policy reform.
Charge-Exchange Scattering of Negative Pions at 150 Mev

The charge-exchange scattering of pi /sup -/ by hydrogen was measured at a bombarding energy of 150 Mev. The energy distribution of gamma rays from the decay of pi /sup 0/ was measured with a lead glass Cherenkov counter at laboratory angles of 45, 75, 105, and 135 deg . If the charge exchange differential scattering cross section in the center-of-mass system is expanded as a series of Legendre polynomials, the result is: d sigma /d OMEGA = (1.00 plus or minus 0.03)STA3.39 plus or minus 0.11 -- (1.54 plus or minus 0.29)P/sub 1/ (cos theta ') + (3.57 plus or minus 0.56)P/sub 2/(cos theta ')!mb-sr/sub -1/. The tot al cross section for charge exchange, obtained by integration, is then sigma /sub tot/( pi /sup -/ yields pi /sup 0/) = 42.6 plus or minus 1.9 mb. (auth)
Effects of gamma-linolenic and dihomo-gamma-linolenic acids on 7,12-dimethylbenz(α)anthracene-induced mammary tumors in rats

The effects of pure gamma-linolenic acid (GLA; C18:3, n-6) and dihomo-gamma-linolenic acid (DGLA; C20:3, n-6) were investigated in 7,12-dimethylbenz(alpha)anthracene (DMBA) (10 mg/rat)-induced mammary tumors in Sprague-Dawley rats. 0.15 g of GLA, DGLA, or corn oil (CO) were administered (two times per week) by oral intubation, for 12 weeks to rats maintained on a 5% (w/w) CO diet. Tumor incidence, tumor multiplicity, and percent of tumor-bearing rats were highest in the CO group. Tumor multiplicity was significantly reduced in the GLA group (p = 0.015). Feeding of GLA and DGLA resulted in significant alterations in levels of these fatty acids in phospholipids of mammary tissue, thymus, colon, liver, stomach, and ovary. These results suggest that GLA may have a small, but significant, inhibitory effect on the development of DMBA-induced mammary tumors in rats.
On the Role of Local Grain Interactions on Twin Nucleation and Texture Evolution in Hexagonal Materials

Texture evolution in plastically deformed HCP metals is strongly influenced by the nucleation and growth of deformation twins and twin variant selection. Statistically based EBSD analyses of deformed microstructures in HCP metals indicate that the nucleation of deformation twins depends on, among other factors, the local stress fields arising from neighboring grain interactions at grain boundaries [1]. Inspired by these findings a probability model for twin nucleation was developed [2,3], based on the activation of defect sources statistically occurring in grain boundaries. This nucleation model was implemented in a Visco-Plastic Self-Consistent (VPSC) code. Because the latter is based on an Effective Medium assumption and the inclusion formalism, it only provides average stress values in the grains, and the nature of local stress fields at grain boundaries had to be considered in a heuristic manner. In order to have better insight on the effect of local textures on twin nucleation, in this work we employ a viscoplastic full field Fast Fourier Transform (FFT) method as a numerical tool for conducting virtual experiments to study the role of crystal orientation and local neighbor grain interactions on stress localization close to the interfaces and, consequently, on twin nucleation in hexagonal materials, such as Zr and Mg.
A neutral loss activation method for improved phosphopeptide sequence analysis by quadrupole ion trap mass spectrometry.

Recent advances in phosphopeptide enrichment prior to mass spectrometric analysis show genuine promise for characterization of phosphoproteomes. Tandem mass spectrometry of phosphopeptide ions, using collision-activated dissociation (CAD), often produces product ions dominated by the neutral loss of phosphoric acid. Here we describe a novel method, termed Pseudo MSn, for phosphopeptide ion dissociation in quadrupole ion trap mass spectrometers. The method induces collisional activation of product ions, those resulting from neutral loss(es) of phosphoric acid, following activation of the precursor ion. Thus, the principal neutral loss product ions are converted into a variety of structurally informative species. Since product ions from both the original precursor activation and all subsequent neutral loss product activations are simulataneously stored, the method generates a “composite” spectrum containing fragments derived from multiple precursors. In comparison to analysis by conventional MS/MS (CAD), Ps...
High current density aluminium stabilized conductor concepts for space applications

The authors report on a high-current-density aluminium-stabilized conductor concept for large spaceborne energy storage inductors. High-purity-aluminium-stabilized NbTi composite conductors cooled by 1.8-K helium can provide a winding current density up to 15 kA/cm/sup 2/ at fields up to 10 T. The conductors are edge-cooled with enough surface area to provide recovery following a normalizing disturbance. The conductors are designed so that current diffusion time in the high-purity aluminium is smaller than the thermal diffusion time in helium. Conductor design, stability, and current diffusion are considered. The numerical analysis of transient stability shows that aluminium-stabilized conductors with final resistivity ratio greater than 800 can be stable in a 1.8-K pressurized helium II bath up to 50 kA (J=15 kA/cm/sup 2/) at fields up to 10 T. single-layer toroids are preferred over multilayer ones because of their simplicity of construction, large current requirement, and better magnetoresistance. >
Effects of Environmental Calcium and Sodium on Postharvest Survival of Juvenile Striped Bass

Abstract Experiments were conducted at two Georgia Department of Natural Resources hatcheries over a 4-year period to determine ways of reducing high mortality of striped bass Morone saxatilis during the first day after harvest. Survival rates at 24 h postharvest were determined for 5-week-old juveniles held in untreated hatchery water (8–10 mg/L total hardness as CaCO3) or in the same water with addition of either CaCl2 (278 mg/L) or NaCl (5 g/L), or of both salts combined (CaCl2+NaCl). Mean survival rates in three experiments at Walton Hatchery (three replicates per treatment in each experiment) were 91% with added CaCl2+NaCl, 48% with CaCl2, 16% with untreated water, and 12% with NaCl. Treatment means for CaCl2+NaCl, CaCl2, and untreated water were significantly different (P 0.05). For the same treatments in nine experiments at McDuffie Hatchery, survival rates were 99.6, 95, 76, and 30%, respectively. At McDuffie ...
Dietary Deprivation of B-Vitamins Reflected in Murine Splenocyte Proliferation in Vitro

The effect of murine dietary deprivation of specific B-vitamins on in vitro splenocyte proliferative response in short-term tissue culture was examined in serum-free, protein-free, minimal medium. Using different media formulations, incorporation of [3H]thymidine was used to monitor the relative growth capacity of phytohemagglutinin-stimulated splenocytes from mice exposed to different diets. The results demonstrate that the growth deficit observed in vitro in the absence of specific vitamin(s) in the medium correlates only to those specific vitamin(s) eliminated from the diet. Dietary repletion is followed by restoration of a normalized response in vitro. The finding that murine dietary experience is reflected in vitro in splenocyte proliferative response monitored by [3H]thymidine incorporation suggests that human dietary experience might be monitored by similar analysis of human peripheral blood lymphocyte response.
The use of Flourocarbon Gases to Prevent Arc-Over in DC Capacitors

The use of Fr-14 (CF 4 ) and Fr-116 (C 2 F 6 ) to increase the margin arc-over voltage in dry Mylar energy storage capacitors is investigated. It is found that pressurization of capacitors with Fr-14 results in a small increase in arc-over voltage. However, pressurization with Fr-116 results in arcover voltages 1.5 to 2.5 times larger than obtained in air.
Testosterone suppression of mesenchymal alkaline phosphatase activity and lympho-epithelial nodule formation in the bursa of Fabricius in the embryonic chick.

The relatively strong alkaline phosphatase activity of the subepithelial mesenchyme of the bursa during the period of lympho-epithelial nodule formation (12–15 days of incubation) and the close association of vascular channels with surface epithelium at sites of nodule formation suggest the possible role of these factors in induction and/or development of these nodules. Experimental inhibition of nodular formation and development may be accomplished by the administration of testosterone prior to the onset of this process (e.g., 12th day of incubation). One-tenth milliliter (2.5 mg) of testosterone propionate in sesame oil (Schering) was administered on the tenth, eleventh and twelfth days of incubation. Bursas from 136 experimental and 64 control embryos were removed on the thirteenth, fifteenth and eighteenth days of development, fixed in cold 80% ethanol and embedded in paraffin. Alkaline phosphatase activity was demonstrated by the Gomori's glycerophosphate procedure using incubation times of one-half, two and four hours at 37°C. Testosterone administered on the twelfth day produced a moderate decrease in alkaline phosphatase activity and markedly reduced nodule formation and subsequent development. When administered on the eleventh day, however, alkaline phosphatase activity was greatly reduced and essentially complete inhibition of nodular formation was accomplished. The possible direct inhibitory effect of testosterone on alkaline phosphatase activity (and possibly other mesenchymal cell functions) and the resulting inhibition of lympho-epithelial nodule formation during embryogenesis of the bursa of Fabricius is suggested.
Existence and nonexistence of positive radial solutions for some semilinear elliptic problems in annular domains

Au + f(]x], U) = 0 in S&u = 0 on XJ, (*) when n is some annulus and the above conditions in [4,29] are not necessarily satisfied. In fact, in our main result (theorem 2.4), f is not necessarily C’, lim f(t, u)/u may not exist (or may be U-+rn finite) and f(t, u) could be zero for u in some finite interval [0, p]. We also allow lim (f(t, u)/u) > 0 (corollary 2.6) and lim (f(t, u)/u) may not exist. (In example 2.3 below, U+O u-0 neither lim f(u)/u, nor lim f(u)/u exists.) On the other hand, we show that u-0 u-m
Recurrence in pituitary adenomas in childhood and adolescence.

Pediatric pituitary adenomas are thought to behave more aggressively than their adult counterparts, and the ability to predict the degree of such behavior remains elusive. Proliferation marker Ki-67 and tumor suppressor gene p53 mutations have been used in adults to assist in the evaluation of invasiveness and recurrence; however, their use in childhood and adolescence remains anecdotal. Our study evaluates the proliferative potential in pituitary adenomas of five patients and its relationship with recurrence or persistence of endocrinologic or clinical abnormalities. For such assessment, tissues were stained with monoclonal antibodies BP53-12 for p53 tumor suppressor gene mutation and MIB-1, which binds to cell cycle-specific nuclear antigen Ki-67. In our series, one patient with recurrent adenoma demonstrated the highest (50%) p53 immunoreactivity. Ki-67-stained nuclei ranged from 0 to 2%, failing to identify the recurrent tumor. Therefore, p53 immunoreactivity, rather than Ki-67 nuclear stain, may be u...
The meal pattern of rats shifts from postprandial regulation to preprandial regulation when only five meals per day are scheduled.

Abstract In order to investigate whether an observed difference in the meal patterns of rats and humans may be due to constraints that humans have on the timing of meals and their large but infrequent meal pattern, rats had similar constraints imposed on their meal intake. Fifteen male Long-Evans rats were monitored in five individual enclosed chambers equipped with pellet sensing eatometers for three fourteen-day data collection periods. Both groups were monitored in a baseline ad lib condition, then one group (n=7) was allowed access to food only once every two hours, while the second group (n=8) was allowed to access only five times per day. Both groups were then monitored for a second ad lib baseline period. The imposition of both schedules reduced meal frequencies and estimated premeal stomach contents, and increased meal sizes and estimated postmeal stomach contents. The imposition of the five meal per day, but not the twelve meal per day schedule of meal access, eliminated the significant relationships between meal size and the postmeal interval evident during baseline conditions and produced significant relationships between meal size and the premeal interval and estimated premeal stomach content, not seen during baseline conditions. The rats under the five meal per day access schedule showed a preprandial pattern of intake very similar to that previously observed in humans eating ad lib. It was concluded that the preprandial pattern, typical of humans, is characteristic of intake involving large infrequent meals which produce stomach filling to an upper limiting threshold. The postprandial pattern, typical of rats, is characteristic of intake involving small frequent meals that are initiated when the stomach empties to a lower threshold. A peripheral, stomach capacity, model then, can be used to explain both the preprandial and the postprandial patterns. Which pattern is used depends upon environmental conditions.
Ti:sapphire based ultrafast pump-probe laser source in the violet and ultraviolet

Frequency conversion of an ultrafast 810 nm Ti:sapphire laser has produced 15 mJ, 165-fs pulses at 405 nm with an energy conversion efficiency of 35%. Upon tripling the fundamental to 270 nm, an energy of 0.8 mJ is obtained. Unconverted 405-nm light is used to generate an ultrafast supercontinuum in water that extends from 200 nm to 600 nm. The system operates at a 5 Hz repetition rate, and is useful for applications in deep ultraviolet pump-probe ultrafast spectroscopy.
The coronary risk factor problem: a behavioral perspective.

Abstract This paper examines the conditions under which one would expect to observe the development and perpetuation of preventive health behavior patterns in populations. It is hypothesized that preventive health behavior is a function of both macro-level societal constraints and micro-level organizational, group, and individual factors. The concept of the “at risk” or “high-risk” role is developed and contrasted with the traditional sick and illness roles. Based on the behavioral science literature, the following macro-level factors are presented as predictors of preventive health behavior: (a) legislation and economic incentives; (b) social norms and cultural patterns; (c) training and consequent practices of physicians and other health professionals; and (d) organization of health services. On the micro-level, the following predictors of preventive health behavior can be supported: (a) social supports from primary and reference groups; (b) socialization of children; (c) formal organizational sanctions; and (d) individual motivation and responsibility. In support of the theoretical framework, the paper draws upon the literature reviewed in the recent American Heart Association Monograph Applying Behavioral Science to Cardiovascular Risk . The authors describe some current risk factor intervention studies and conclude with a proposal for community intervention projects with simple, quasi-experimental designs in which outside facilitators would initiate programs and continuing education for local health professionals who would eventually assume responsibility for their perpetuation.
Hydrolysis of estrogen conjugates by the lungs of the dog in vivo.

Although hydrolysis of certain estrogen conjugates released into the systemic circulation is now known to occur in the human and in the dog, the site or sites of such hydrolysis remain unidentified. In an attempt to identify such sites, radioactive estrone was infused intravenously into a series of male dogs and serial paired samples of blood were obtained from the right ventricle (RV) and a peripheral artery (A). The samples were analysed for total radioactivity, unconjugated radioactive estrogens, radioactive estrone, estradiol-17β, estrone sulfate, estrone glucosiduronate and estradiol-17β glucosiduronate(s). The mean was calculated for each radioactive moiety analyzed. There was no significant percent extraction of total radioactivity or of estrone sulfate. The mean percent extractions for unconjugated estrogens and for estrone and estradiol-17β were −24.7, −21 and −34.3 respectively (P < 0.01), indicating net production by the lungs. The mean percent extractions for estrone glucosiduronate and estrad...
Transport of sodium and potassium in intestinal epithelial cells.

Abstract Transport properties of rabbit small intestinal mucosa were investigated in vitro to characterize the process by which epithelial cells maintain normal Na and K gradients across the cell membrane. Active transport of Na from the cell proceeded at a faster rate in the presence of K; and active transport of K into the cell was stimulated by the presence of Na. Following preincubation at 0°C to reduce tissue K content, a greater transmural electrical potential difference (PD) and short-circuit current (Isc) developed as the temperature was raised to 37°C if K was present in the bathing solution. The PD and Isc, which generally reflect the rate of active Na transport in ileum under control conditions, increased immediately upon raising the K concentration in the serosal solution from 0 to 10 nM. The results present the first direct indication in mammalian intestine of an interdependence of the Na and K active transport processes which regulate the intracellular content of these cations.
Incentive mechanisms for smoothing out a focused demand for network resources

We explore the problem of sharing network resources when users' preferences lead to temporally concentrated loads, resulting in an inefficient use of the network. In such cases external incentives can be supplied to smooth out demand, obviating the need for expensive technological mechanisms. Taking a game-theoretic approach, we consider a setting in which bandwidth or access to service is available during different time slots at a fixed cost, but all agents have a natural preference for choosing the same time slot. We present four mechanisms that motivate users to distribute the load by probabilistically waiving the cost for each time slot, and analyze the equilibria that arise under these mechanisms.