cssi/SciSciGPT-SciSciNet huggingface dataset:
MOLECULAR STRUCTURE-PROPERTY RELATIONSHIPS FOR ELECTRON-TRANSFER RATE ATTENUATION IN REDOX-ACTIVE CORE DENDRIMERS

Two series of redox-active, iron−sulfur core dendrimers of the general structure (nBu4N)2[Fe4S4(S-Dend)4] (Dend = dendrons of generations 1 through 4) were prepared. Heterogeneous electron-transfer rate constants indicated that the rigid series of dendrimers were more effective at attenuating the rate of electron transfer than were the flexible series of dendrimers. These results were rationalized using computationally derived models which indicated an offset and mobile iron−sulfur core in the flexible series of molecules and a more central and relatively immobile iron−sulfur core in the rigid series of molecules. Further consideration of these data indicated that, while the dendrimers containing rigid ligands had better encapsulated redox cores for a given molecular weight, these molecules had higher electron-transfer rates for a given molecular radius.
Research progress on plastic bronchitis

Plastic bronchitis is a rare, multisystem, clinical syndrome characterized by endobronchial, tubular, and localized or extensive obstruction resulting in acute fatal respiratory distress.The disease is more common in infectious diseases in China, but it is reported abroad after the operation of congenital heart disease.The treatment of plastic bronchitis is a challenging problem with a high mortality rate and no effective treatment has been introduced.The bronchoscope as an acute phase can only relieve symptoms of treatment recognized by domestic and foreign scholars, drug treatment is various, but there is no uniform standard, bronchodilators, hypertonic saline, leukotriene modifiers, macrolides, glucocorticoid, mucolytic agent, heparin, fibrinolytic agents, heart replacement and cardiopulmonary replacement therapy has been mentioned in clinical application.The pathogenesis of plastic bronchitis is not clear and the clinical manifestations are diverse.Early diagnosis and treatment are particularly important. Key words: Plastic Bronchitis; Etiology; Pathogenesis; Diagnosis; Treatment
Effects of Contrast-Enhanced Ultrasound of Indeterminate Renal Masses on Patient Clinical Management: Retrospective Analysis From 2 Institutions.

OBJECTIVES To investigate the long-term impact of contrast-enhanced ultrasound (CEUS) on the treatment of patients with indeterminate renal masses. METHODS In this retrospective study, consecutive charts of all patients receiving renal CEUS at 1 of 2 academic medical centers between January 1, 2014, and December 31, 2018, were reviewed. Patients were included in the study if they had documented chronic renal disease (estimated glomerular filtration rate < 60 mL/min/1.73 m2 ) or prior nephrectomy and received CEUS for a previously untreated renal mass. RESULTS A total of 215 lesions in 157 patients were used for analysis. Contrast-enhanced ultrasound provided a final treatment recommendation in 71.6% of lesions (154 of 215). Of these 154 lesions, 7.8% (12 of 154) were lost to follow-up despite CEUS suggesting malignancy; 15.6% (24 of 154) went directly for surgical intervention, with malignancy confirmed by pathologic results in 87.5% (21 of 24) of these cases; and the remaining 76.6% (118 of 154) were deemed benign and required no additional follow-up. Of the 118 lesions diagnosed by CEUS as benign and requiring no follow-up, none showed evidence of later renal cell carcinoma development and, only 5.1% (6 of 118) of the total population was referred for further cross-sectional imaging of the mass in question. In 28.4% of all lesions (61 of 215), CEUS resulted in a recommendation for surveillance imaging at a 6- to 12-month interval, and less than 10% (6 of 61) of these underwent additional cross-sectional imaging within the recommended 6 months after CEUS. CONCLUSIONS These findings highlight the impact of CEUS on clinical treatment of indeterminate renal masses, including reducing the use of the potentially nephrotoxic contrast agents and providing a direct pathway to transplant.
Nestin selectively facilitates the phosphorylation of the Lissencephaly-linked protein doublecortin (DCX) by cdk5/p35 to regulate growth cone morphology and Sema3a sensitivity in developing neurons

Abstract Nestin, an intermediate filament protein widely used as a marker of neural progenitors, was recently found to be expressed transiently in developing cortical neurons in culture and in developing mouse cortex. In young cortical cultures, nestin regulates axonal growth cone morphology. In addition, nestin, which is known to bind the neuronal cdk5/p35 kinase, affects responses to axon guidance cues upstream of cdk5, specifically, to Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, and changes in microtubules and actin filaments are well studied. In contrast, the roles of intermediate filament proteins in this process are poorly understood, even in cultured neurons. Here, we investigate the molecular mechanism by which nestin affects growth cone morphology and Sema3a sensitivity. We find that nestin selectively facilitates the phosphorylation of the lissencephaly-linked protein doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected by nestin. We uncover that this substrate selectivity is based on the ability of nestin to interact with DCX, but not with other cdk5 substrates. Nestin thus creates a selective scaffold for DCX with activated cdk5/p35. Lastly, we use cortical cultures derived from DCX knockout mice to show that the effects of nestin on growth cone morphology and on Sema3a sensitivity are DCX-dependent, thus suggesting a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating the intracellular kinase signaling environment in developing neurons. Significance Statement Nestin, an intermediate filament protein highly expressed in neural progenitors, was recently identified in developing neurons where it regulates growth cone morphology and responsiveness to the guidance cue Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, but the roles of intermediate filaments in this process are poorly understood. We now report that nestin selectively facilitates phosphorylation of the lissencephaly-linked doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected. This substrate selectivity is based on preferential scaffolding of DCX, cdk5, and p35 by nestin. Additionally, we demonstrate a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating intracellular kinase signaling in developing neurons.
An Exploration of Limit-Setting in Child Counseling

Therapeutic limit-setting in child counseling can be a critical part of the child’s growth process. Intentional limit-setting is a critical skill for beginning and advanced counselors, who can use ...
Assessing the climate for research ethics in labs: Development and validation of a brief measure.

The environment researchers work in influences their ethical decisions and behavior. A “climate” for research ethics in a research lab exists when members of the lab perceive that the group values ...
Transfer-Free Synthesis of Atomically Precise Graphene Nanoribbons on Insulating Substrates

The rational bottom-up synthesis of graphene nanoribbons (GNRs) provides atomically precise control of widths and edges that give rise to a wide range of electronic properties promising for electronic devices such as field-effect transistors (FETs). Since the bottom-up synthesis commonly takes place on catalytic metallic surfaces, the integration of GNRs into such devices requires their transfer onto insulating substrates, which remains one of the bottlenecks in the development of GNR-based electronics. Herein, we report on a method for the transfer-free placement of GNRs on insulators. This involves growing GNRs on a gold film deposited onto an insulating layer followed by gentle wet etching of the gold, which leaves the nanoribbons to settle in place on the underlying insulating substrate. Scanning tunneling microscopy and Raman spectroscopy confirm that atomically precise GNRs of high density uniformly grow on the gold films deposited onto SiO2/Si substrates and remain structurally intact after the etching process. We have also demonstrated transfer-free fabrication of ultrashort channel GNR FETs using this process. A very important aspect of the present work is that the method can scale up well to 12 in. wafers, which is extremely difficult for previous techniques. Our work here thus represents an important step toward large-scale integration of GNRs into electronic devices.
Hepatitis B Vaccination Among Adults With Diabetes Mellitus, U.S., 2018.

INTRODUCTION Hepatitis B vaccination is routinely recommended for adults with diabetes mellitus aged <60 years and for those aged ≥60 years at the discretion of their healthcare provider. The purpose of this study is to assess hepatitis B vaccination coverage among adults with and without diabetes mellitus. METHODS Data from the 2014-2018 National Health Interview Survey were analyzed in 2020 to determine hepatitis B vaccination series completion (≥3 doses) among adults aged 18-59 and ≥60 years with diabetes mellitus. Multivariable logistic regression analysis was conducted to identify the factors independently associated with hepatitis B vaccination among adults aged 18-59 and ≥60 years with diabetes mellitus. RESULTS In 2018, among adults aged 18-59 years with diabetes mellitus, 33.2% had received hepatitis B vaccination (≥3 doses), an increase of 9.7 percentage points from 2014 (p<0.05). Among adults aged ≥60 years with diabetes mellitus, coverage was 15.3% in 2018 and did not increase during 2014-2018. Coverage was not significantly different among adults with diabetes mellitus compared with those without diabetes mellitus, even after controlling for the assessed factors. Among adults with diabetes mellitus aged 18-59 and ≥60 years, younger age, having some college or college education, having been tested for HIV, being healthcare personnel, or having traveled to hepatitis B virus-endemic areas were independently associated with an increased likelihood of vaccination. CONCLUSIONS Self-reported hepatitis B vaccination coverage among adults with diabetes mellitus remains suboptimal. Healthcare providers should assess patients' diabetes status, recommend and offer needed vaccinations to patients, or refer them to alternate sites for vaccination.
Surgical correction of pediatric spinal deformities with coexisting intraspinal pathology: A case report and literature review

Background Surgical correction of spinal deformities with coexisting intraspinal pathology (SDCIP) requires special consideration to minimize risks of further injury to an already abnormal spinal cord. However, there is a paucity of literature on this topic. Here, the authors present a pediatric patient with a residual pilocytic astrocytoma and syringomyelia who underwent surgical correction of progressive postlaminectomy kyphoscoliosis. Techniques employed are compared to those in the literature to compile a set of guidelines for surgical correction of SDCIP. Methods A systematic MEDLINE search was conducted using the following keywords; "pediatric," "spinal tumor resection," "deformity correction," "postlaminectomy," "scoliosis correction," "intraspinal pathology," "tethered cord," "syringomyelia," or "diastematomyelia." Recommendations for surgical technique for pediatric SDCIP correction were reviewed. Results The presented case demonstrates recommendations that primarily compressive forces on the convexity of the coronal curve should be used when performing in situ correction of SDCIP. Undercorrection is favored to minimize risks of traction on the abnormal spinal cord. The literature yielded 13 articles describing various intraoperative techniques. Notably, seven articles described use of compressive forces on the convex side of the deformity as the primary mode of correction, while only five articles provided recommendations on how to safely and effectively surgically correct SDCIP. Conclusion The authors demonstrated with their case analysis and literature review that there are no clear current guidelines regarding the safe and effective techniques for in situ correction and fusion for the management of pediatric SDCIP.
Neutron diffraction tomography: A unique 3d inspection technique for crystals using an intensifier TV system

The application of phosphor-intensifier-TV techniques to neutron topography and tomography of crystals is described. The older, analogous x-ray topography using wavelengths approximately 1.5A is widely used for surface inspection. However, the crystal must actually be cut in order to see diffraction anomalies beneath the surface. Because 1.5-A thermal neutrons are highly penetrating, much larger and thicker specimens can be used. Also, since neutrons have magnetic moments, they are diffracted by magnetic structures within crystals. In neutron volume topography, the entire crystal or a large part of it is irradiated, and the images obtained are superimposed reflections from the total volume. In neutron tomography (or section topography), a collimated beam irradiates a slice (0.5 to 10 mm) of the crystal. The diffracted image is a tomogram from this part only. A series of tomograms covering the crystal can be taken as the specimen is translated in steps across the narrow beam. Grains, voids, twinning, and other defects from regions down to 1 mm in size can be observed and isolated. Although at present poorer in resolution than the original neutron and film methods, the TV techniques are much faster and, in some cases, permit real-time viewing. Two camera systems are described:more » a counting camera having a 150 mm /sup 6/Li-ZnS screen for low-intensity reflections which are integrated in a digital memory, and a 300-mm system using analog image storage. Topographs and tomograms of several crystals ranging in size from 4 mm to 80 mm are shown.« less
Estradiol distribution during the development and expression of reproductive structures in Populus tremuloides Michx.

Estradiol (E2) was measured in spring and winter tissues in several populations of dioecious Populus tremuloides Michx. and in four trees with perfect flowers. A correlation between the concentration of E2 and sex expression was observed. In catkins, E2 concentrations increased before anthesis, peaked during flowering, and decreased as flowers matured. The increases were concurrent with sporogenesis and development of gametophytes. Statistically significant seasonal variation in E2 concentration was also evident. Dormant winter tissues showed significantly lower E2 concentrations than spring tissues. Branches exposed to relatively more light had significantly higher E2 content in both spring and winter. Seasonal variation in E2 content was also observed in trees of the same sex, among branches of the same tree, and among different organs.
Reaction mechanism of 12C(16O, α): 12C transfer to nuclear molecular resonances

Abstract Various reaction mechanisms are examined for the 12 C ( 16 O , α) reaction at 145 MeV incident energy. The direct transfer of 12C to the nuclear molecular states can consistently explain the observed features of the peaks in the α-particle spectra, while many other processes contribute to the smooth background.
Directional coupling and switching in multi-core microstructure fibers

A systematic study of directional coupling in dual- and multi-core microstructure fibers is presented. We introduce a fully three-dimensional, efficient and versatile method for modeling light propagation in index-guiding microstructure fibers. Using this model, the coupling length for the two most efficient configurations (/spl radic/3/spl Lambda/ and 2/spl Lambda/ inter-core separation) is determined as a function of the structural parameters (hole diameter and pitch) and wavelength.
Evolution of mapmaking: learning, planning, and memory using genetic programming

An essential component of an intelligent agent is the ability to observe, encode, and use information about its environment. Traditional approaches to genetic programming have focused on evolving functional or reactive programs with only a minimal use of state. This paper presents an approach for investigating the evolution of learning, planning, and memory using genetic programming. The approach uses a multi-phasic fitness environment that enforces the use of memory and allows fairly straightforward comprehension of the evolved representations. An illustrative problem of 'gold' collection is used to demonstrate the usefulness of the approach. The results indicate that the approach can evolve programs that store simple representations of their environments and use these representations to produce simple plans. >
Microsatellite instability in colorectal adenomas

BACKGROUND & AIMS: Microsatellite instability in apparently sporadic, predominantly right-sided colon cancers seems to be the result of an acquired, rather than germline, genetic change that impairs mismatch repair. The timing of this change with respect to the adenomacarcinoma sequence has not been determined. The aim of this study was to evaluate colonic adenomatous polyps for microsatellite instability to determine whether instability reflects an early genetic change in colonic neoplasia. METHODS: Ninety-three sporadic colonic adenomas (44 right- sided and 49 left-sided) from 48 individuals were evaluated for microsatellite instability with a set of 10 polymerase chain reaction primer sets. RESULTS: Eighty percent of adenomatous polyps showed no instability. Ninety-eight percent showed instability with <30% of primer sets. Aside from one right-sided adenoma with 78% instability, there was no level of instability with a higher proportion of right- sided than left-sided adenomas. CONCLUSIONS: Colonic adenomas show far less microsatellite instability than carcinomas, and the marked right- sided predominance of instability observed in colon cancers was not observed. Instability is usually not an early event in the development of colonic neoplasia. A distinct pathway to sporadic colorectal cancer initiated by mismatch repair deficiency, although not excluded, is not suggested by these data. (Gastroenterology 1997 May;112(5):1515-9)
The mystery of Julius: A paradox in decision theory

L'A. expose, sous la forme d'un dialogue entre un etudiant et son professeur de logique, le mystere de Julius qui consiste a mettre a l'epreuve la theorie de la decision developpee par R. Jeffrey. Par analogie avec le paradoxe de l'echange, l'A. etudie les notions fondamentales de preference, desirabilite, probabilite, possibilite et utilite, a la lumiere de la theorie de la reference de S. Kripke
Peace Profile: Wangari Maathai and the Green Belt Movement

There are a few human rights activists whose actions had the power to positively affect their families, friends, and neighbors. A very small number of these advocates have further influenced their ...
Science diaries: a brief writing intervention to improve motivation to learn science

This study investigated the hypothesis that prompting students to self-assess their interest and understanding of science concepts and activities would increase their motivation in science classes. Students were randomly assigned to an experimental condition that wrote self-assessments of their competence and interest in science lessons or a control condition that wrote summaries of those same lessons. Writing activities were 10 min long and were given approximately once a week for eighteen weeks. Student motivation was assessed via self-report surveys for achievement goals and interest in science before and after the intervention. Students in the experimental condition showed higher endorsement of mastery goals and reported greater situational interest in science topics after the intervention compared to students who summarised the lessons. Increases in situational interest predicted higher individual interest in the domain. Results indicate an instructional practice requiring just 3 hours out of a semes...
Architecture and Dynamics of Isotopically Labelled Macromolecules by Nuclear Magnetic Resonance Spectroscopy

The last two decades were a period of luxuriant growth in the X-Ray Crystallography of biological macromolecules that has led to remarkably detailed correlations between their structure and function (1). A particularly outstanding example is the elegant work of Perutz and his colleagues on the structure of hemoglobins which resemble “molecular lungs” (2) in their mode of O2/CO2 binding and release. The family of serine proteases provide another example and, in this case, x-ray structural studies have resulted in an elaborate picture of the mechanism of the action of this class of enzymes (3,4); however, the detailed picture is not without its controversial elements (5).
Patrons versus planners: The political contradictions of integrated rural development in Swaziland

(1986). Patrons versus planners: The political contradictions of integrated rural development in Swaziland. Journal of Contemporary African Studies: Vol. 5, No. 1-2, pp. 119-144.
Electron beam induced degradation of polyperfluorinated ethers: -(CF(CF3)-CF2-O)n-, for n = 4, 8 and 50

Abstrac Polyperfluorinated propylene oxides, -(CF(CF 3 )-CF 2 O-) n -, where n = 4 , 8 and 50, are exposed to electron beams and their subsequent degradation monitored via infrared spectroscopy at T = 11 and 298 K. COF 2 , CF 4 , and R-CFO are produced and their G values are reported as a function of n , the number of monomer units, in the polymer. The G values range from 0.1 to 3, depending upon the gas product and n . The efficiency for gas evolution decreases with increasing number of monomer units. For n = 4, R-CFO, CF 4 and COF 2 are produced with G values of 3.0, 2.7, and 2.4, respectively. As n increases to 50, COF 2 becomes the dominant product with a G value of 1.0, followed by CF 4 at 0.7, and R-CFO at 0.1.
METHOD OF IMPROVING THE TEACHING OF PARTICLE PHYSICS IN A NONCALCULUS COURSE OF PHYSICS

The Klein Gordon equation–which describes mesons–can be reformulated to suit students who have no calculus background. The method is arrived at from a review and a reinterpretation of the mechanics of small oscillations. It may serve as a model for the design of new instructions for other areas of particle physics.
Amino acid containing phospholipids as major components of the phospholipids of Streptococcus faecalis 10C1

Abstract Four major components were found m the phospholipids of Streptococcus faecalis 10C1. Alanyl phosphatidyl glycerol is the major component and may comprise as much as 80% of the phospholipid. During the log phase of growth it decreases to about 40% but if constant pH is maintained during growth, it rises during the stationary phase while the amount of phosphatidyl glycerol and diphosphatidyl glycerol decrease. The second component is lysyl phosphatidyl glycerol which tends to increase during the growth cycle in uncontrolled cultures but decreases from 35 to 20% of the phospholipid during late log phase in cultures with controlled pH. The two lesser components are phosphatidyl glycerol and diphosphatidyl glycerol. While cells and cell free preparations incorporated [14C]lysine into lysyl phosphatidyl glycerol, they did not incorporate exogenous alanine into alanyl phosphatidyl glycerol.
Fitness and the risk of illness and “spectrum disorder” in offspring, parents, and siblings

As shown by Essen-Moller [(1955).Acta Genet.5:334–342] and Risch [(1983).Behav. Genet.13:441–451], the effect of a disorder on fitness can substantially influence the risk of illness in relatives. This report expands on previous treatments by examining (1) the impact of fitness on the risk for illness and “spectrum disorder” in offspring, parents, and siblings as a function of the fitness of ill and spectrum individuals and (2) the effect on the risk of illness in relatives where fitness is related to the severity of illness. When fitness is the same for all affected individuals, decreasing fitness has little effect on the risk of spectrum or illness in offspring, diminishes rates of illness but increases rates of spectrum in parents, and diminishes rates of both illness and spectrum in siblings. When inversely correlated with severity of illness, fitness effects on risk of illness and spectrum in offspring can be nontrivial. Furthermore, as the fitness of the severe form of illness decreases, the risk in parents decreases for the severe form but increases for the mild form. For a trait with a substantial effect on fitness, misleading results may be produced by model fitting with risk data from relatives unless the pattern of fitness of spectrum, mildly affected, and severely affected individuals is taken into account.
Conditional Assertions and “Biscuit” Conditionals

1. “Biscuit” Conditionals~1! There are biscuits on the sideboard if you want some~2! If you’re interested, there’s a good documentary on PBS tonightand~3! Oswald shot Kennedy, if that’s what you’re asking me,as they’d typically be used, are examples of what are often called “biscuit” con-ditionals, after J.L. Austin’s example ~~1!, above; see Austin, 1970, p. 212!.Amark of such a conditional is that, after it has been uttered, it can only be a certainkind of joke to ask what is the case if the antecedent is false—“And where are thebiscuits if I don’t want any?”, “And what’s on PBS if I’m not interested?”, “Andwho shot Kennedy if that’s not what I’m asking?”. With normal indicative con-ditionals like,~4! There are biscuits on the sideboard if Bill hasn’t moved them~5! If the TV Guide is accurate, there’s a good documentary on PBS tonightand~6! Oswald shot Kennedy, if there hasn’t been an enormous conspiracy,
Extensive survey of STAT6 expression in a large series of mesenchymal tumors.

Objectives: Expression of strong nuclear STAT6 is thought to be a specific marker for solitary fibrous tumors (SFTs). Little is known about subtle expression patterns in other mesenchymal lesions. Methods: We performed immunohistochemical studies against the C-terminus of STAT6 in tissue microarrays and whole sections, comprising 2366 mesenchymal lesions. Results: Strong nuclear STAT6 was expressed in 285 of 2,021 tumors, including 206 of 240 SFTs, 49 of 408 well-differentiated/dedifferentiated liposarcomas, eight of 65 unclassified sarcomas, and 14 of 184 desmoid tumors, among others. Expression in SFTs was predominately limited to the nucleus. Other positive tumors typically expressed both nuclear and cytoplasmic STAT6. Complete absence of STAT6 was most common in pleomorphic liposarcoma and alveolar soft part sarcoma (60% and 72% cases negative, respectively). Conclusions: Strong nuclear STAT6 is largely specific for SFTs. Physiologic low-level cytoplasmic/nuclear expression is common in mesenchymal neoplasia and is of uncertain significance.
Maximal and minimal balls

Abstract Let S be a set of balls in R d. We call a ball in S maximal if no other ball in S contains it, and minimal if it contains no other ball. The expected number of maximal and minimal balls in a set of n independent and identically distributed random balls is investigated. These quantities are found to be o(n) for any absolutely continuous distribution. Their behavior is investigated more precisely for three specific distributions. It is also shown that Bentley, Clarkson, and Levine's move-to-front strategy provides an efficient algorithm for identifying maximal minimal balls. Since only maximal balls lie on the boundary of the convex hull of the set, this provides a good preprocessing step for constructing the convex hull of a set of balls.
Intralipid infusion into humans reduces in vitro platelet aggregation and alters platelet lipid composition

Intralipid (Kabi Vitrum Inc, Alameda, CA) infusion into normal volunteers results in substantial elevation in serum triglyceride, phospholipids, and free cholesterol concentrations. Platelet aggregation induced in vitro in platelet-rich plasma by collagen or ADP was significantly reduced by up to 40% and 45%, respectively, during the infusion period but returned to preinfusion levels 18 hours after the end of the infusion. In parallel, platelet lipid composition was also affected. Platelet free cholesterol content was reduced by up to 20% during the infusion of Intralipid, whereas platelet triglyceride and phospholipid contents increased by 3.5-fold and twofold, respectively. Eighteen hours after the end of the infusion, both platelet cholesterol and triglyceride returned to preinfusion levels, but platelet phospholipid was still elevated. Both components of Intralipid (liposomes and triglyceride-phospholipid particles) were able to decrease in vitro platelet aggregation and platelet cholesterol content. Our results demonstrate decreased platelet function induced by Intralipid infusion into humans, which was associated with reduced platelet cholesterol content. These results suggest possible antiatherogenic effects of infusing Intralipid in humans.
Sea-floor dynamic processes as the possible cause of correlations between paleoclimatic and paleomagnetic indices in deep-sea sedimentary cores

Abstract Recent publications showing correlations between the variation of intensity of magnetization(J) and paleomagnetic inclinationI on the one hand, and diverse paleoclimatic indices on the other, have been interpreted to represent direct cause and effect relationships between climate and geomagnetism. It is proposed that several sea-floor dynamic processes, which are climatically variable, are at least equally feasible causes of the observed correlations. Thus, for variation inJ, it is a simple matter to invoke variations in such factors as the magnetic particle size fraction below 50 microns, carbonate content, or laminar flow layer thickness, all of which can change with climate. For variation inI, climatically related variation of the velocity gradient in the laminar flow layer can be employed to explain the correlation. Prior to accepting the suggested geomagnetic control of climate as real, it is recommended that simple measurements of the temporal and geographic variation in fabric and composition of the deep-sea sediments involved should be carried out, as a check for the effect of bottom dynamic processes.
SU-D-137-06: Effect of Dose-Per-Pulse and Pulse Repetition Frequency in X-Ray Beam Irradiation of In-Vitro Cell Cultures

Purpose: It has been reported that flattening‐filter‐free (FFF) beams may have a different biological effect than flattened beams, possibly due to the increased dose‐per‐pulse in FFF beams. The purpose of this work is to determine if in‐vitro cell survival is affected by the higher dose‐per‐pulse and/or repetition rates generated by flattening‐filter‐free beams in comparison to flattened beams. Methods: three cell lines, T98G (p53 mutant human glioblastoma), U87‐MG (p53 wild type human glioblastoma) and V79‐4 (Chinese hamster lung fibroblast) were irradiated to 5 Gy and 10 Gy with Linac X‐ray photon energies of 6 MV, 6 MV FFF and 10 MV FFF, using dose rates of 400, 1400 and 2400 MU/min. The relative variation of the average dose‐per‐pulse among the beams was measured as 1.0: 2.8: 4.6 for 6X: 6XFFF: 10XFFF. The dose delivered to each sample was verified with a parallel‐plate ionization chamber. Gafchromic film measurements were made to confirm the dosimetry methodology. Clonogenic cell survival assays were used to evaluate biological effect of each beam. Three or more biological replicates were performed for each experiment. Results: For T98G cells, surviving fractions at 5 Gy for 6MV at 400 MU/min, 6MVFFF for 400MU/min and 1400MU/min, 10XFFF 400MU/min and 2400MU/min, were 0.59(0.09), 0.53(0.07), 0.55(0.08), 0.58(0.08), and 0.60(0.07) respectively. For U87‐MG also at 5 Gy surviving fractions were 0.27(0.02), 0.29(0.05), 0.29(0.05), 0.32(0.05), and 0.31(0.06). For V79‐4 survival at 5 Gy was 0.59(0.12), 0.56(0.06), 0.50(0.08), 0.51(0.03), and 0.54(0.04). Increased cell killing was observed using 10 Gy doses but no difference in biological effect among beams was observed. Conclusion: No effects due to dose‐per‐pulse or pulse repetition frequency variation were observed on cell killing at either 5 Gy or 10 Gy for any of the cell lines tested.
Design and initial performance evaluation of DbPET2, an intermediate generation breast PET prototype

The combined effort of several laboratories at our institution resulted in the building of the first dedicated, breast PET/CT prototype. Ongoing clinical trials for breast cancer diagnosis and assessment of response to treatment underlined the need of a second generation prototype with improved sensitivity and spatial resolution. The goals of the new prototype are to reduce scan time and partial volume effects on quantitative measurements of small lesions. Several designs have been proposed by our group and are currently under investigation at different levels. In this work, we present the complete characterization of a detector module for an intermediate generation breast PET prototype, together with its design and assembly. The proposed design consists of two heads, shaped around the circumference of a circle of radius 26 cm. Each head is formed by 2 rows of 8 modules each, each module consisting in a 14×14 array of unpolished LSO crystals, read out by a position sensitive photomultiplier tube (PSPMT). Crystal pitch is 1.5 mm. A complete characterization of two detectors modules in coincidence resulted in an energy resolution of 25.2%, a timing resolution of 2.4 ns and an average intrinsic spatial resolution for a central row in the array of 1.26 mm. The two detector heads are now fully assembled and connected to the electronics suite for data processing. Modification of the system electronics is underways and the first floods, showing excellent position encoding, are presented. A thorough evaluation of system performance will be completed in the next few months. We plan to combine this scanner with a third generation breast CT system currently under parallel development to form a new generation, dedicated breast PET/CT scanner.
Effects of remifentanil on the contractility of failing human heart muscle.

Objective: The purpose of this study was to determine the direct effects of remifentanil on inotropy of human myocardial tissue removed from failing explanted hearts of cardiac transplant recipients. Design: In vitro, prospective study with repeated measures. Setting: Research laboratory in a tertiary referral center. Interventions: The authors studied the effects of remifentanil on isometric myocardial contractile parameters in failing atrial and ventricular myocardial muscles. The authors also used 1 μmol/L of isoproterenol to test adrenergic responsiveness of failing myocardial tissues in the presence of supratherapeutic remifentanil concentrations. Measurements and Main Results: Muscles were studied at 37°C and 1 Hz, with concentrations of remifentanil covering a wide range of therapeutic as well as supratherapeutic concentrations (ie, between 0.001 and 100 μg/mL). After the dose-response curve was obtained, the author measured the inotropic response to 1 μmol/L of isoproterenol in the presence of the cumulative dose of remifentanil. Over the wide range of concentrations, remifentanil had no significant effect on contractile function. In the presence of supratherapeutic concentration of remifentanil, isoproterenol produced a 97% ± 58% increase in developed tension in failing atrial muscles and a 91% ± 40% increase in failing ventricular muscles, which did not significantly differ from control muscles. Conclusions: The authors showed that remifentanil had no significant negative inotropic effects in failing human heart muscle and that myocardial contractility remained fully responsive to β-adrenergic stimulation at all remifentanil concentrations studied.
Hyphal wall chemistry in Apodachlya

Hyphal walls were isolated from the Oomycete, Apodachlya sp. Microscope examination of wall preparations showed that they were clean and relatively free of cellulin granules. The principal wall constituents, accounting for more than half of wall weight, were β-glucans with 1,3- and 1,6-glucosidic linkages. Apparently chitin was the second most abundant wall constituent (18%) and cellulose accounted for less than 10% of wall weight. Protein was a significant wall constituent (6.4%), and protein hydrolysis demonstrated nearly all common amino acids plus hydroxyproline; additionally, the unusual amino acid, hydroxylysine was tentatively identified. The lipid and ash constituents were small (1.7% and 0.4%, respectively) and no particular significance was assigned to them. The possible occurrence of wall glycoproteins and the relationship between wall chemistry and systematics in Apodachlya and related genera were discussed.
Guest Editor's Introduction: Pervasive Computing for Emerging Economies

Ubiquitous computing has the potential to cut across cultures and countries, to be both locally valuable and globally pervasive. To reach this potential, it's important for researchers to recognize the challenges, rewards, goals, and methods of developing these technologies--not just in wealthy IT-saturated environments, but in developing economies and regions as well.
Converging prevalences of obesity across educational groups in Switzerland.

Objective: To assess whether the rapid increase in obesity prevalence among persons with higher education levels observed in one U.S. study is also observed in a European adult population. Research Methods and Procedures: This study involved continuous surveillance of the adult population of Geneva, Switzerland (1993 to 2004), with annual random, independent, cross-sectional, representative samples (6635 men and 6558 women, ages 35 to 74 years) and analysis of 12-year trends in obesity prevalence across educational level subgroups. Results: Obesity prevalence in men had an upward trend in the medium education subgroup (p < 0.02), a borderline upward trend in the high education subgroup (p < 0.08), but no trend in the low education subgroup. There was a borderline trend interaction between the male low and medium education subgroups (p < 0.09). Obesity prevalence in women had a borderline increase in the low education subgroup (p < 0.08), an almost borderline increase in the high education subgroup (p = 0.11), but no significant trend in the medium education subgroup. There was no evidence of trend interaction between the female education groups. Discussion: In Geneva, as in the United States, the inverse association between education level and obesity rates has weakened over time among men, but, inconsistent with the U.S. findings, has persisted for women. Explanations may include more physically demanding occupations for men with low education levels and different attitudes toward body image between the sexes.
On the Structure-Function correlates of Ion Occupancy and modulation of C-type Inactivation

KcsA, a proton activated K channel, has served as an archetypical K pore providing molecular insights into understanding selectivity, ion-permeation, gating and pore-blocking. A recent set of crystal structures describing the mechanism of C-type inactivation in this channel now allows for an understanding this mechanism at atomistic level. Our results show that KcsA inactivation is strongly coupled to the opening of the activation gates and is modulated by the amount and direction of current passing through the channels. As also implicated by studies in eukaryotic channels, C-type inactivation in KcsA involves an intimate interplay between the selectivity-filter region and permeant-ions. This study attempts at further understanding this close association between the ion and filter by correlating high resolution structures with macroscopic and single- channel functional data. We have obtained several KcsA crystal structures of the closed and the open mutant channel, in the presence of different permeant ions (K+, Rb+, Cs+ and NH4+) and blockers (Ba2+ and TEA). These structures reveal different ion occupancies depending upon the nature of the permeant ion, blocker and the extent of channel opening. Analyzed in the light of extensive functional evidence, these results uncover several important features of the interplay between ion interactions and the evolution of C-type inactivation.
Retinoic acid is a major regulator of chondrocyte maturation and matrix mineralization.

During the process of endochondral bone formation, chondrocytes undergo a series of complex maturational changes. Our recent studies indicate that this maturational process is influenced by the vitamin. A derivative retinoic acid (RA). To learn how this agent regulates chondrocyte development, we characterized matrix gene expression during maturation of cartilage cells in chick sternum. RNAs were isolated from the cephalic portion of day 13, 14, 16, 18, and 20 chick embryo sternum and analyzed via northern blots. Type II collagen RNA levels remained fairly constant during this developmental period. In contrast, expression of type X collagen and alkaline phosphatase (APase) genes was first detected at day 16, followed by that of ostenection (ON) and osteopontin (OP). To explore the mechanisms triggering these changes, chondrocytes were isolated from the cephalic portion of day 17–18 sternum (US cells) and grown in monolayer in standard serum-containing medium. After 3 weeks in culture, most of the cells enlarged and became type X collagen-positive, but they exhibited low APase activity and contained only trace amounts of ON and OP mRNAs. Treatment of parallel 3-week-old cultures with RA (10–100 nM) rapidly increased expression of the APase, ON, and OP genes severalfold. In concert with a significant increase in APase activity, there was abundant calcium accumulation in the RA-treated cultures. Electron microscopy confirmed the formation of large matrix-associated mineral crystals and the presence of numerous matrix vesicles. The effects of RA were also studied in cultures of immature chondrocytes isolated from the caudal portion of sternum (LS cells). In these cells, RA failed to induce high levels of APase activity, ON and OP gene expression, and mineralization; instead, it greatly promoted cell proliferation. Thus RA appears to have major, stage-specific effects on the maturation program of chondrocytes. The retinoid rapidly induces expression of late maturation genes and activates mineralization of the cartilage matrix. © 1994 Wiley-Liss, Inc.
Radiative transfer in spherical shell atmospheres. III. Application to Venus

A method for partitioning the radiance emerging from a planetary atmosphere in proportion to the average number of scatterings in each atmospheric layer is applied to Venus in order to account for the various atmospheric levels which contribute to the radiance. A backward Monte Carlo technique is used to calculate core and continuum radiances for the P(16) line of the 8689-A CO2 band for various phase angles and colatitudes in a realistic model of the Venus atmosphere. Effective temperatures for the radiance are defined in two ways, both of which are shown to vary little with phase angles up to 120 deg, and fall rapidly beyond this point, in accordance with spectroscopic results. Temperature increases on the order of 7 K and 10 K are found going from the core of the line to the continuum for colatitudes of 90 and 20 deg, respectively, and the effective temperature is calculated to decrease from equator to pole. An effective optical depth is also defined, which, together with the concepts of effective temperature and effective height, is considered to bring a more fundamental understanding of the concept of level of line formation.
Spectral Radius Design for Robust Multivariable Control

A sufficient condition for robust stability and disturbance rejection in multivariable control systems is presented. The condition is a bound on the spectral radius of a weighted set of closed loop transfer function matrices. Frequency dependent weighting matrices are determined from structured bounds on plant uncertainties and performance specifications. For certain clases of robust control problems, including nonminimum phase systems, the spectral radius has a particularly simple form that leads directly to graphical methods for control synthesis. Though the bounds are conservative, the technique does lead to simple graphical interpretations. This is illustrated for systems subject to additve plant perurbations and with performance constraints on both the control input and output error.
UPTAKE OF ACROLEIN IN THE UPPER RESPIRATORY TRACT OF THE F344 RAT

AbstractTo provide inhalation dosimetric information for acrolein vapor, the uptake of this irritant was measured during a 40-min exposure period in the surgically isolated upper respiratory tract (URT) of the anesthetized male F344 rat at selected unidirectional inspiratory (50–300 ml/min) or pseudo-cyclic (1 ml volume, 100 cycles/min with 7 ml/min being continuously bled off for analysis) flow conditions. In addition, the effect of acrolein on URT uptake of acetone vapor was studied via this approach to determine if this irritant was capable of altering the uptake of other vapors. In contrast to numerous other vapors, URT uptake of acrolein did not attain or maintain a steady state during the exposure, but rather slowly decreased throughout the 40-min exposure period. Average URT acrolein deposition efficiency (between 20 and 40 min of exposure) was significantly dependent (p < .001) on the inspired concentrations, with average deposition efficiencies of 62, 38, and 28% being observed at inspired concen...
Gentamicin nephrotoxicity. I. Acute biochemical correlates in rats.

Abstract Following acute exposure (1.5 hr) to 100 mg/kg gentamicin sulfate, renal cortical homogenates from treated rats showed a 45% reduction in the activity of the basolateral enzyme marker, Na+,K+-ATPase, while enzymes associated with the brush border membrane and other cellular organelles were not significantly altered. Tissue slice respiration, transport of p-aminohippuric acid (PAH), and N1-methylnicotinamide (NMN) and ionic content (Na, K, Ca) were unaffected by treatment. Cortical slices from gentamicin-treated rats showed a decreased capacity to extrude Na and regain K with respect to controls after cooling (0°C) and subsequent rewarning (37°C). Although light microscopic analyses revealed no significant changes in renal cortex 1.5 hr following injections of 50 to 350 mg/kg gentamicin, electron microscopy detected the presence of increased numbers of cytosegresomes at all doses. No other histopathological changes were evident. These results indicate that gentamicin affects the basolateral membrane of the proximal tubule and that inhibition of Na+,K+-ATPase may be related to the pathogenesis.
DNA methylation determination by liquid chromatography–tandem mass spectrometry using novel biosynthetic [U-15N]deoxycytidine and [U-15N]methyldeoxycytidine internal standards

Methylation of the promoter CpG regions regulates gene transcription by inhibiting transcription factor binding. Deoxycytidine methylation may regulate cell differentiation, while aberrations in the process may be involved in cancer etiology and the development of birth defects (e.g. neural tube defects). Similarly, nutritional deficiency and certain nutragenomic interactions are associated with DNA hypomethylation. While LC-MS has been used previously to measure percentage genomic deoxycytidine methylation, a lack of a secure source of internal standards and the need for laborious and time-consuming DNA digestion protocols constitute distinct limitations. Here we report a simple and inexpensive protocol for the biosynthesis of internal standards from readily available precursors. Using these biosynthetic stable-isotopic [U-15N]-labeled internal standards, coupled with an improved DNA digestion protocol developed in our lab, we have developed a low-cost, high-throughput (>500 samples in 4 days) assay for measuring deoxycytidine methylation in genomic DNA. Inter- and intraassay variation for the assay (%RSD, n = 6) was <2.5%.