cssi/SciSciGPT-SciSciNet huggingface dataset:
Arterial spin labeling MRI for assessment of perfusion in native and transplanted kidneys

Abstract Purpose To apply a magnetic resonance arterial spin labeling (ASL) technique to evaluate kidney perfusion in native and transplanted kidneys. Materials and Methods This study was compliant with the Health Insurance Portability and Accountability Act and approved by the institutional review board. Informed consent was obtained from all subjects. Renal perfusion exams were performed at 1.5 T in a total of 25 subjects: 10 with native and 15 with transplanted kidneys. A flow-sensitive alternating inversion recovery (FAIR) ASL sequence was performed with respiratory triggering in all subjects and under free-breathing conditions in five transplant subjects. Thirty-two control/tag pairs were acquired and processed using a single-compartment model. Perfusion in native and transplanted kidneys was compared above and below an estimated glomerular filtration rate (eGFR) threshold of 60 ml/min per 1.73 m 2 and correlations with eGFR were determined. Results In many of the transplanted kidneys, major feeding vessels in the coronal plane required a slice orientation sagittal to the kidney. Renal motion during the examination was observed in native and transplant subjects and was corrected with registration. Cortical perfusion correlated with eGFR in native ( r =0.85, P =.002) and transplant subjects ( r =0.61, P =.02). For subjects with eGFR >60 ml/min per 1.73 m 2 , native kidneys demonstrated greater cortical ( P =.01) and medullary ( P =.04) perfusion than transplanted kidneys. For subjects with eGFR 2 , native kidneys demonstrated greater medullary perfusion ( P =.04) compared to transplanted kidneys. Free-breathing acquisitions provided renal perfusion measurements that were slightly lower compared to the coached/triggered technique, although no statistical differences were observed. Conclusion In conclusion, FAIR-ASL was able to measure renal perfusion in subjects with native and transplanted kidneys, potentially providing a clinically viable technique for monitoring kidney function.
A novel apparatus for the measurement of the phase and volumetric behavior at high temperatures and pressures and its application to study VLE in the hydrogen-tetralin system

Abstract A new apparatus that was developed to measure VLE data for H 2 -hydrocarbon systems, at elevated temperatures and pressures, is described. This apparatus was used to measure VLE data of H 2 -tetralin mixtures at 423.15, 462.75, 541.85, and 621.75 K, and up to 27.33 MPa.
Graphic Aids in Reporting Technical Information

This is one of the papers from technical writing students that the Journal publishes from time to time.The use of visual aids to complement technical writing is described, especially in reference to two main categories: static and dynamic images.
Schrödinger particle as the source of a Yang-Mills field

Solutions to the Yang-Mills field equations in the presence of extended external sources are reviewed. Point sources have qualitatively different solutions than do extended sources. A model of a nonrelativistic particle in an external potential interacting self-consistently with the Yang-Mills field is used to see whether the particle's wave function acts as an extended source. This model is discussed in detail and a gauge, analogous to the London gauge, is used to set up an initial-value problem for its equations of motion. For small gauge coupling g we find no evidence of solutions with lower energy than a simple Abelian solution. Such a lower-energy solution may, however, exist for large coupling.
Different Worlds: A Cultural Perspective on Nurse-Physician Communication

Nurses and physicians have a unique opportunity to work together to provide quality patient care. Although numerous studies have documented the value of effective nurse-physician communication on patient outcomes and on nurse and physician satisfaction, communication between many physicians and nurses continues to be poor. A variety of reasons for this disconnect have been identified, including differences in education, role expectations, gender, and approach to practice. Based on the principle that it is more important to understand than to be understood, application of a cultural competence model offers nurses the opportunity to better understand their physician colleagues. Because of the imperative to provide sensitive care to a diverse population, nurses are expected to assess cultural variations when planning care. That same skill can be applied to improving professional relationships with physicians. This article proposes application of a cultural competence model as a framework to assist nurses to better understand physicians with whom they work. With a focus on how culture affects one's world view, nurses will be encouraged to employ this cultural competence model in their interactions with physicians.
Self-Criticism, Failure, and Depressive Affect: A Test of Personality–Event Congruence and Symptom Specificity

Diathesis-stress models of cognitive vulnerability to depression posit that personality factors (e.g., self-criticism) interact with congruent negative life events to produce distinct depressive symptom clusters. The present study employed a stress-induction procedure to assess whether self-criticism would interact with achievement-related failure to increase introjective depressive affect in a nonclinical sample. Hypotheses were generally supported with respect to introjective depressive affect reported immediately following the stress-induction procedure. However, self-criticism did not interact with achievement failure in predicting depressive affect reported 24 hours later.
Multivacuum initial conditions and the arrow of time

Depending on the type and arrangement of metastable vacua in the theory, initial conditions in a de Sitter vacuum with arbitrarily large entropy can be compatible with the observed arrow of time, if the causal patch or related measures are used to regulate divergences. An important condition, however, is that the initial vacuum cannot produce observers from rare fluctuations (Boltzmann brains). Here we consider more general initial conditions where multiple vacua have nonzero initial probability. We examine whether the prediction of an arrow of time is destroyed by a small initial admixture of vacua that can produce Boltzmann brains. We identify general criteria and apply them to two nontrivial examples of such initial probability distributions. The Hartle-Hawking state is superexponentially dominated by the vacuum with smallest positive cosmological constant, so one might expect that other initial vacua can be neglected; but in fact, their inclusion drastically narrows the range of theory parameters for which an arrow of time is predicted. The dominant eigenvector of the global rate equation of eternal inflation is dominated by the longest-lived metastable vacuum. If an arrow of time emerges in the single-initial-vacuum approximation, then we find that this conclusion survives the admixture of other initial vacua. By global-local measure duality, this result amounts to a successful consistency test of certain global cutoffs, including light-cone time and scale-factor time.
Donepezil: an update

Donepezil hydrochloride is the most widely prescribed drug for Alzheimer's disease (AD). The main mechanism of action through which it influences cognition and function is presumed to be the inhibition of acetylcholinesterase enzyme in the brain; however, donepezil may also impact the pathophysiology of AD at several other points. Officially approved for mild-to-moderate and severe AD, donepezil has also been shown to be effective in early-stage AD, vascular dementia, Parkinson's disease dementia/Lewy body disease and cognitive symptoms associated with multiple sclerosis. In addition, one study suggested that donepezil may delay the onset of AD in subjects with mild cognitive impairment, a prodrome to AD. The pharmacokinetics, pharmacodynamics, safety/tolerability profile and drug interaction properties of donepezil make it an easy and safe agent to use. However, in general, the efficacy of donepezil is limited, and ongoing studies are investigating other agents that may ultimately overtake its present position as the mainstay of anti-AD therapy.
Universal and Solution-Processable Precursor to Bismuth Chalcogenide Thermoelectrics

We describe a universal precursor to compounds of the form Bi2Te3−xSex. This precursor can be dispensed using traditional solution-processing techniques and then thermally decomposed into its respective parent compound. Room temperature measurements of these materials yield thermoelectric figures of merit, ZT, ranging from 0.2 to 0.4.
Dissection of chromosome 16p12 linkage peak suggests a possible role for CACNG3 variants in age-related macular degeneration susceptibility.

PURPOSE. Age-related macular degeneration (AMD) is a complex disorder of the retina, characterized by drusen, geographic atrophy, and choroidal neovascularization. Cigarette smoking and the genetic variants CFH Y402H, ARMS2 A69S, CFB R32Q, and C3 R102G have been strongly and consistently associated with AMD. Multiple linkage studies have found evidence suggestive of another AMD locus on chromosome 16p12 but the gene responsible has yet to be identified. METHODS. In the initial phase of the study, single-nucleotide polymorphisms (SNPs) across chromosome 16 were examined for linkage and/or association in 575 Caucasian individuals from 148 multiplex and 77 singleton families. Additional variants were tested in an independent dataset of unrelated cases and controls. According to these results, in combination with gene expression data and biological knowledge, five genes were selected for further study: CACNG3, HS3ST4, IL4R, Q7Z6F8, and ITGAM. RESULTS. After genotyping additional tagging SNPs across each gene, the strongest evidence for linkage and association was found within CACNG3 (rs757200 nonparametric LOD* 3.3, APL (association in the presence of linkage) P 0.06, and rs2238498 MQLS (modified quasi-likelihood score) P 0.006 in the families; rs2283550 P 1.3 10 6 , and rs4787924 P
Global optimization of omnidirectional wavelength selective emitters/absorbers based on dielectric-filled anti-reflection coated two-dimensional metallic photonic crystals

We report the design of dielectric-filled anti-reflection coated (ARC) two-dimensional (2D) metallic photonic crystals (MPhCs) capable of omnidirectional, polarization insensitive, wavelength selective emission/absorption. Using non-linear global optimization methods, optimized hafnium oxide (HfO2)-filled ARC 2D Tantalum (Ta) PhC designs exhibiting up to 26% improvement in emittance/absorptance at wavelengths λ below a cutoff wavelength λc over the unfilled 2D TaPhCs are demonstrated. The optimized designs possess high hemispherically average emittance/absorptance eH of 0.86 at λ λc.
Hemoglobin resonance Raman excitation profiles with a tunable dye laser

Resonance Raman spectra have been obtained for oxy hemoglobin within the α absorption band, corresponding to the first π – π* transition, using a tunable dye (Rhodamine 6 G) laser. The excitation profiles demonstrate resonance at the electronic origin (0–0), as well as at the vibronic side-band (0–1) frequency, as predicted by theory. The wavelength dependence of the Raman intensity follows the molar absorptivity, rather than its square. It is suggested, however, that this form of the wavelength dependence may be an artifact of the transition from resonance to pre-resonance scattering.
Laptop Computers in the Elementary Classroom: Authentic instruction with at‐risk students

This case study investigated the integration of laptop computers into an elementary classroom in a low socioeconomic status (SES) school. Specifically, the research examined classroom management techniques and aspects of authentic learning relative to the student projects and activities. A mixed methods approach included classroom observations, interviews with the teacher, interviews with the students, and analysis of student projects. The results provide insight regarding the benefits and challenges of integrating wireless technology in an elementary classroom with at‐risk students. In addition, the project resulted in a web site with sample lesson plans (including objectives, required materials, NETS competencies and extension activities), teacher reflections and training tips. Les ordinateurs portables dans la classe elementaire: un enseignement authentique avec des eleves ‘a risque’ La presente etude de cas porte sur l'integration des ordinateurs portables dans une classe elementaire d'une ecole pour ...
The in vivo mutagenicity and mutational spectrum at the lacI transgene recovered from the spleens of B6C3F1 lacI transgenic mice following a 4-week inhalation exposure to 1,3-butadiene

1,3-Butadiene (BD) is carcinogenic and mutagenic in B6C3F1 mice. We determined the lacI mutant frequency and mutational spectrum in spleen following inhalation exposure to BD at levels that are known to induce tumors. B6C3F1 lacI transgenic mice were exposed to air or to 62.5, 625, or 1250 ppm BD for 4 weeks (6 h/day, 5 days/week) and euthanized 14 days after the last exposure. BD increased the lacI mutant frequency in spleen at all levels of BD examined. In BD-exposed mice, an increased frequency of G:C-->A:T transitions occurred at non-5'-CpG-3' sites. Exposure to BD in B6C3F1 lacI transgenic mice also increased the frequency of base substitution mutations that occurred at A:T base pairs when compared to air controls. The increased frequency of specific mutations at G:C base pairs in spleen was not observed in our previous studies in bone marrow and indicates tissue-specific differences in the BD-induced mutational spectrum. These data demonstrate that in vivo transgenic mouse mutagenicity assays can identify tissue-specific mutagenicity and mutational spectrum responses of genotoxic carcinogens at exposure levels that are known to induce tumors.
HISTORICAL PRE AND POST SPECIAL CLOSING EFFECTS

This study examines the historical return behavior surrounding foreseeable or expected special closings of the New York Stock Exchange. Pre and Post special closing return behavior supports no existing hypothesis, but instead clearly demonstrates a new pre and post special closing effect similar to the pre and post holiday effect found by Ariel (1990, 1987).
Scheduling in Flash-Based Solid-State Drives - Performance Modeling and Optimization

In this paper, we study the performance of solid-state drives that employ flash technology as storage medium. Our prime objective is to understand how the scheduling of the user-generated read and write commands and the read, write, and erase operations induced by the garbage-collection process affect the basic performance measures throughput and latency. We demonstrate that the most straightforward scheduling that prioritizes the processing of garbage-collection-related commands over user-related commands suffers from severe latency deficiencies. These problems can be overcome by using a more sophisticated priority scheme that minimizes the user-perceived latency without throughput penalty or deadlock exposure. Using both analysis and simulation, we investigate how these schemes perform under a variety of system design parameters and workloads. Our results can be directly applied to the engineering of a performance-optimized solid-state-drive system.
Pyrite removal from Illinois #6 coal by CrCl2 reduction and effect of pyrite on the coprocessing of Illinois #6 coal with waste automotive oil

Abstract Pyrite was removed from Illinois #6 coal by HF/HCl washes and by CrCl 2 reduction. The effect of pyrite on the coprocessing of Illinois #6 coal with waste automotive oil was investigated. ICP results show that the standard HF/HCl treatment still leaves about 65% of the pyrite in the Illinois #6 coal, but acidic CrCl 2 reduction can remove 95.9% of the pyrite from the same coal without causing significant alteration of the organic matter as shown by examination of samples before and after treatment by infrared and 13 C NMR spectroscopy as well as by atomic ratios (H/C, N/C and S organic /C). XPS results show that compared to untreated Illinois #6 coal, the inorganic composition on the surface of CrCl 2 treated Illinois #6 coal changes very little except for loss of pyrite, whereas the inorganic composition of HF/HCl treated Illinois #6 coal changes substantially. A comparison between untreated coal and CrCl 2 treated Illinois # 6 coal was made by TOF-SIMS (Time-of-Flight Secondary-Ion Mass Spectroscopy). Nearly total removal of pyrite from Illinois #6 coal by CrCl 2 decreases the conversion yield of the coal to THF solubles to 16.2%, compared to 60.9% for untreated Illinois #6 coal and 53.4% for HF/HCl treated Illinois #6 when each of these coals is coprocessed with waste automotive oil under the same reaction conditions. This comparison of conversion yields of the coal further supports the conclusion reached previously that pyrite functions as a catalyst aiding in dissolution of the coal to form gas, oil, asphaltenes and char.
The Luna 20 lithic fragments, and the composition and origin of the lunar highlands

The petrology of Luna 20 lithic fragments is described and compared to that of other highland sites. An identification of the major types of rocks that compose the lunar terrae is attempted, and their probable petrogenesis is discussed.
The E2F1–3 transcription factors are essential for cellular proliferation

The retinoblastoma tumour suppressor (Rb) pathway is believed to have a critical role in the control of cellular proliferation by regulating E2F activities1,2. E2F1, E2F2 and E2F3 belong to a subclass of E2F factors thought to act as transcriptional activators important for progression through the G1/S transition3. Here we show, by taking a conditional gene targeting approach, that the combined loss of these three E2F factors severely affects E2F target expression and completely abolishes the ability of mouse embryonic fibroblasts to enter S phase, progress through mitosis and proliferate. Loss of E2F function results in an elevation of p21Cip1 protein, leading to a decrease in cyclin-dependent kinase activity and Rb phosphorylation. These findings suggest a function for this subclass of E2F transcriptional activators in a positive feedback loop, through down-modulation of p21Cip1, that leads to the inactivation of Rb-dependent repression and S phase entry. By targeting the entire subclass of E2F transcriptional activators we provide direct genetic evidence for their essential role in cell cycle progression, proliferation and development.
Analysis of the variation in chromosome size among diverse human populations by bivariate flow karyotyping

Chromosomes sampled from seven human populations were analyzed by flow cytometry to survey normal variation in chromosome size. The populations include two African Pygmy groups, two Amerindian tribes, Druze, Khmer Cambodians, and Melanesians. Mitotic chromosomes were isolated from cultured cells and stained with Hoechst 33,258 and chromomycin A3. The relative DNA content and base-pair composition of each homolog was quantified by bivariate flow karyotyping. Significant variation in DNA content, ranging from 10-40%, was observed for chromosomes 1, 13-16, 19, 21, 22, and Y. The measurements for each population appeared to be a random sampling of the total set of 33 individuals for the majority of chromosomes. A few significant differences in the distributions of chromosomal DNA content were observed among the populations, however. The data, when combined with an earlier study of 33 unrelated individuals of unknown ethnic origin, provide a good representation of the variation in chromosome size among humans.
Medical management of benign prostatic hyperplasia with androgen suppression

Many types of nonsurgical therapy, including balloon dilation, hyperthermia, adrenergic blockade, and hormonal therapy, have been used for the treatment of benign prostatic hyperplasia (BPH). Antiandrogen therapy has been the most extensively studied form of hormonal treatment for BPH, although estrogens, antiestrogens, and antiprolactin agents have also been used (Scott and Coffey: Vitam Horm 33:439-465, 1975). The theoretical basis of antiandrogen therapy will be reviewed along with a summary of relevant clinical trials. Recent advances in the development of agents that more selectively inhibit the androgen-dependent growth of the prostate will be presented.
Google web toolkit for OGCE gadget based architecture

This paper introduces a gadget-based web 2.0 architecture for building scientific and educational tools. This architecture builds on ideas from both Google Web Toolkit (GWT) and Google gadget and adds AJAX functionality. The gadgets developed with GWT are hosted in the Open Gateway Computing Environments (OGCE) container. The community of scientific applications and science gateways developers face the challenges of rapid development of scientific and educational tools for their users. This web application development approach allows developers to create a gadget graphical user interface within hours and, thus, can potentially expand the variety of OpenSocial Gadgets. A gadget that has been developed using our gadget-based architecture for online Community Earth System Model (CESM) simulations is presented as a use case in this paper.
Acute changes in infranodal conduction time following left ventriculography and sublingual nitroglycerin administration in man

Abstract During diagnostic cardiac catheterization for the evaluation of chest pain, His bundle electrograms were obtained in 32 male patients before and 2 to 5 minutes after each of two interventions known to acutely affect left ventricular volume and left ventricular end-diastolic pressure (the injection of 40 to 60 cc of contrast medium during left ventriculography and the administration of 0.4 mg of sublingual nitroglycerin). Changes in left ventricular end-diastolic pressure (18 ± 6 vs 30 ± 7 mm Hg, p p p p
A Eureka Moment [Microwave Surfing]

Five years ago, while I was in China (accompanying my younger daughter on a high-school field trip), I had the opportunity to experience the magnetic levitation technology firsthand when our group boarded the Shanghai Maglev Train [1] on the way to the Pudong International airport. Although the ride lasted only around seven minutes, the 267 mi/h top speed certainly provided an exhilarating experience.
Plasma ion balance of North American freshwater turtles during prolonged submergence in normoxic water

Abstract 1. 1. Plasma ion (Na+, K+, Cl−, HCO−3, lactate, Ca, and Mg) concentrations were measured during apneic submergence in aerated water at 10°C of 4 species of freshwater turtles: Chelydra serpentina serpentina (Chelydridae), Chrysemys picta bellii (Emydidae), Sternotherus odoratus (Kinosternidae), and Trionyx spiniferus asperus (Trionychidae). Measurements were made at intervals up to 21, 13, 100, and 100 days, respectively. In addition, final wet and dry masses were measured in Sternotherus and Trionyx and compared to control values to assess changes in body water and dry mass. 2. 2. In Chelydra and Chrysemys, which have a relatively poor aquatic O2 uptake capacity, plasma ions changed as previously reported in animals submerged in anoxic water; [Na+] was unchanged, [K+], [Ca], and [Mg] were evaluated, and [Cl−1] and [HCO−3] were depressed. This overall pattern is probably a regulated response and respresents a compensation for the severe acidosis exhibited by these animals. 3. 3. In Sternotherus and Trionyx, which have effective aquatic respiration and could remain submerged much longer, plasma ion concentrations, except [K+] and [lactate], fell due (largely in Sternolherus, less so in Trionyx to dilution by water uptake. Both species were slightly alkalotic after prolonged normoxic submergence, and we suggest that changes in ion concentrations can be considered as compensatory to this alkalosis. 4. 4. We conclude that these turtles fall into two distinct physiologic response types. In Chelydra and Chrysemys, normoxic submergence at 10°C is limited principally by acidosis, and observed plasma ionic changes act to counteract this effect; in Sternotherus, and to a much lesser degree, Trionyx, the limitation is largely osmoregulatory, due to a failure to exclude ambient water and to maintain ionic homeostatasis.
Spatial Proximity to the U.S.-Mexico Border and Newspaper Coverage of Immigration Issues

This article examines how geographic proximity to the U.S.—Mexico border influences newspaper coverage of immigration issues. The authors investigate two questions: Do media organizations spatially...
Optimizing Sudden Passage in the Earth's-Field NMR Technique

Abstract The equation of motion d M/ dt = γM × B( t ) is solved numerically for the case B( t ) = j B p ( t ) + k B e . The field B e is a small static field, typically the earth's field. The field B p ( t ) is a damped oscillation having frequency greater than, or on the order of, the precession frequency in field B e . Such oscillation inevitably occurs at the end of the rapid cutoff of the coil current used to polarize the sample. It is assumed that B p ( t ) is initially large compared to B e , and that magnetization M is initially along the resultant field B. This is the usual situation in the earth's-field NMR technique when the polarizing field is produced by a coil of moderate to high impedance. It is shown that, when properly damped, the transient can be used to restore the magnetization to the x–y plane, thereby maximizing the amplitude of the subsequent free precession signal. The damping required is close to critical damping, so that the problem of circuit ringing when the coil is switched to receiver mode is also eliminated.
Volcanic Activity on lo at the Time of the Ulysses Encounter.

The population of heavy ions in Io's torus is ultimately derived from Io volcanism. Ground-based infrared observations of Io between October 1991 and March 1992, contemporaneous with the 8 February 1992 Ulysses observations of the Io torus, show that volcanic thermal emission was at the low end of the normal range at all Io longitudes during this period. In particular, the dominant hot spot Loki was quiescent. Resolved images show that there were at least four hot spots on Io's Jupiter-facing hemisphere, including Loki and a long-lived spot on the leading hemisphere (Kanehekili), of comparable 3.5-micrometer brightness but higher temperature.
Physical Models and Fundamental Laws: Using One Piece of the World to Tell about Another

In this paper I discuss the relationship between model, theories, and laws in the practice of experimental scale modeling. The methodology of experimental scale modeling, also known as physical similarity, differs markedly from that of other kinds of models in ways that are important to issues in philosophy of science. In this paper, I examine how scale models are used in making inferences. The main question I address is “How are fundamental laws involved in the construction of, and inferences drawn from, experimental scale models?” I propose there is a refreshing alternative to the mainstream view that models can serve only as intermediaries between theory and experiment. Using the methodology of scale models, one can use observations on one piece of the world to make inferences about another piece of the world, without involving an intermediate abstract model about which one reasons. The philosophical significance of that point to philosophy of science is that the method of physical similarity, which provides the basis for inferences based upon scale models, is a qualitatively different way in which fundamental laws can be used in analogical reasoning that is truly informative. Finally, as this method provides a formal basis for case-based reasoning, it may be helpful in formalizing methods used in some of the so-called “special sciences”.
Conflict in the home environment of adolescents from divorced families: A longitudinal analysis

The purpose of this study was to examine conflict in the home environment of adolescents from divorced families across a 3-year period. Adolescents from intact (106) and mother-custody divorced (60) families participated. Interparental conflict and parent-adolescent relations were assessed. Results indicated that adolescents from divorced families did not experience more conflictual home environments than those from intact families. In fact, interparental relations after the first year and parent-adolescent relations in general appeared to be less conflictual in divorced families. Limitations and implications of the findings are discussed.
Genetic algorithm optimization for Bragg cell design

Nonmechanical beam steering technologies utilizing acoustooptics enable us to achieve the high-bandwidth laser beam positioning required for optical communications, laser scanners, ladars, etc. The properties of the Bragg cell, which are chiefly responsible for the efficiency and attainable characteristics of the entire positioning system, are ensured by the successful design of this optical component. However, the design of Bragg cells is dominated by the experience and intuition of the designers, and the potential of this technology is not fully utilized. An optimal Bragg cell design problem is formulated on the basis of known equations of the underlying physical phenomena, and a genetic optimization scheme is applied for the solution of the resulting formidable problem. The approach not only yields a design solution, but also enables one to vary the design criterion and emphasize particular properties of the resultant component. The prowess of the proposed approach is demonstrated by design optimization examples.
Endodermal movements during foregut formation in the chick embryo.

Abstract Insoluble particles of ferric oxide were placed on the endodermal surface of chick embryos in in vitro culture at stage 5–7. The position of the particles which adhered to the endoderm was recorded by photographing the embryos at frequent intervals during the subsequent 20 hours of development, to trace the movements and infoldings of that layer during formation and elongation of the foregut. From stage 6 + to 11 + the length of the foregut increases from about 0.1 mm to about 1.0 mm, during which time its length remains a constant proportion (80%) of the length of the head. During that period the mean areal surface of the subcephalic yolk sac endoderm increases by more than 3-fold, indicating that the elongation of the subcephalic endoderm and floor of the foregut is not accomplished merely by stretching of the tissue present when the AIP first forms. From stage 6 + to about stage 8, endoderm rolls in over the ventral fold of the AIP from the subcephalic yolk-sac endoderm to contribute a substantial—but decreasing—fraction of the elongating floor of the foregut. By the time the foregut has increased in length to 0.7 mm (about stage 9 − ), in-rolling contributes little or nothing to its subsequent elongation. A model of the events occurring in the endoderm is proposed, based upon the behavior of an elastic band, fixed at its two ends and stretched into a U-shape by applying tension near the middle. It is demonstrated that the curve relating the amount of foregut elongation and the fraction of that elongation contributed by in-rolling, obtained from measurements of the experimental embryos fits well with a theoretical curve derived from the model. It is postulated that regression of primitive streak and subjacent endoderm exerts a posteriorly directed tension on the lateral endoderm which is transmitted as a pulling force to the endodermal fold of the AIP, and acts to lengthen the foregut.
Radiofrequency thermal effects on the human meniscus: an in vitro analysis.

Abstract Purpose: The purpose of this study was to evaluate the thermal effects produced in meniscal tissue with different radiofrequency (RF) energy levels and exposure times using a bipolar device. Type of Study: An anatomic in vitro analysis of the thermal effects of an RF device. Methods: A specially designed jig was used to apply RF energy under a constant force to cadaveric menisci. Three different energy levels were applied for 4 different contact times. Results: The overall mean depth of thermal change was 547 μm (range, 468 to 650 μm). There were no significant differences or trends when contact time and energy were varied. Conclusions: These data suggest that increased contact times and energy outputs are not associated with increased thermal change in the meniscus. The submillimeter thermal denaturation was consistent with published reports using other thermal devices, such as laser. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 5 (May-June), 2002: pp 492–495
A proposed interpretation of the destabilizing effect of hydroxyl groups on nitroaromatic molecules

Abstract Whereas an amino group stabilizes nitroaromatic molecules toward shock and impact, presumably through a resonance interaction that strengthens the CNO2 bonds, hydroxyl substituents have a sensitizing effect despite having resonance capabilities. This may reflect the formation, by hydroxyaromatics, of the unstable nitronic acid tautomer. A computational analysis (SCF, 3-21G) of the o-nitrophenol system, used as a model, shows that transfer of the phenolic proton to the nitro group produces an equilibrium nitronic acid structure, with a calculated energy 15.4 kcal/mol above o-nitrophenol. Such proton transfer might result from vibrational excitation of the OH bond produced by shock or impact. No analogous equilibrium structure is found for a possible nitronic acid tautomer of o-nitroaniline.
Aortoesophageal Fistula Secondary to Reflux Esophagitis

Abstract The case reports of 2 patients with exsanguinating hemorrhage from aortoesophageal fistula secondary to reflux esophagitis are presented. One patient underwent closure of the fistula, esophageal diversion, and subsequent esophageal substitution. A high index of suspicion based on the patient's history, results of esophagoscopy, and the rate of bleeding should prompt early left thoracotomy and obliteration of the fistulous tract along with esophageal diversion.
Soybean-lecithin supplementation of practical diets for juvenile goldfish (Carassius auratus)

Soybean lecithin, alone or in combination with cod liver or soybean oil, was tested as a supplemental lipid in practical diets for juvenile (0.3 g) goldfish (Carassius auratus). Goldfish were fed one of five diets containing: (i) 4% cod liver oil (CLO); (ii) 2% CLO+2% lecithin (LEC); (iii) 4% soybean oil (SBO); (iv) 2% SBO+2% LEC; (v) 4% LEC. After 6 wk, weight gain and feed efficiency of fish fed diets with 4% LEC were significantly higher than those of fish fed diets with 4% CLO or SBO. Gain and feed efficiency of fish fed diets with combinations of LEC and CLO or SBO were intermediate. Survival and whole-body lipid were unaffected by diet. Possible mechanisms of performance enhancement in goldfish fed LEC include provision of myoinositol or phosphatidylcholine to support rapid membrane proliferation, enhanced absorption of dietary lipid, and facilitation of lipid transport.
Programming telecommunication networks

The move toward market deregulation and open competition has sparked a wave of serious introspection in the telecommunications service industry. Telecom providers and operators are now required to open up their primary revenue channels to competing industries. The competition for product differentiation increasingly depends on the level of sophistication, degree of flexibility, and speed of deployment of services that a future provider can offer. These factors in turn depend heavily on the flexibility of the software architecture in place in a provider's operational infrastructure. Within this context, we examine the service architecture of two major global communication networks-the telephone network and the Internet and explore their weaknesses and strengths. We discuss the realization of an open programmable networking environment based on a new service architecture for advanced telecommunication services that overcomes the limitations of the existing networks. Our approach to network programmability stems from two angles-one conceptual, the other implementational. In the first, we attempt to develop a service model that is open and reflects the economic market structure of the future telecommunications service industry. Furthermore, we introduce an extended reference model for realizing the service marketplace and present it as a vehicle for creating multimedia services with QoS guarantees. In the second, we investigate the feasibility of engineering the reference model from an implementation standpoint. We describe a realization of the open programmable networking environment as a broadband kernel. Called xbind, the broadband kernel incorporates IP and CORBA technologies for signaling, management, and service creation, and ATM for transport. We also address some of the important QoS, performance, scalability, and implementation issues.
New Mechanism of Cavitation Damage

Enormous impact pressures can develop when a vapor cavity collapses in a liquid, and it is generally held that these pressures are the underlying cause of cavitation damage of surfaces. The rapid g...
Sediment transport in a precambrian ice age: the huronian gowganda formation.

The Gowganda Formation of Ontario consists of conglomerates, quartzites, and argillites deposited in a glacial environment. The distribution of varved argillites and silty limestones suggests continental and marine facies, respectively. Pebble and ripple-drift orientations, distribution of limestones, striated pavements, distribution of the underlying Bruce Group, and Huronian quartzite paleocurrents support the conclusion that sediment transport was from north to south
Polarization problems of parallel plate lasers

Parallel plate laser technology requires that the plasma envelope and particularly the Brewster windows be "hard sealed." The first part of this study reports the effects of misalignments of the Brewster windows on laser performance. This turned out not to be a serious problem. In the second part the increase in the birefringence of the Brewster windows resulting from the hard seal technique is examined. We found that this problem, which is serious, can be eliminated by careful control of the temperature during sealing and the annealing process.
Introducing "Green" and "Nongreen" Aspects of Noble Metal Nanoparticle Synthesis: An Inquiry-Based Laboratory Experiment for Chemistry and Engineering Students.

In recent years, nanoscience and nanotechnology have been drawing enormous attention due to the numerous applications of nanomaterials. In an attempt to nurture interest towards these areas in young minds and to develop the next generation of environmentally conscious scientists and engineers, this new laboratory module focuses on the green and nongreen aspects of noble metal nanoparticles (NPs) synthesis. The element of novelty is represented by the guided, inquiry-based exploration of alternative, green fabrication methods using environmentally friendly reducing agents (e.g., tea extracts, coffee, honey, coconut oil, and banana peel). The inquiry-based learning was developed according to the five essential features laid by the National Research Council (NRC), and was successfully implemented after science and engineering students gained theoretical knowledge and hands-on experience with conventional, nongreen fabrication methods of colloidal silver and gold NPs (i.e., the Lee-Meisel and Turkevich method...
Sleep problems, suicidal ideation, and self-harm behaviors in adolescence

Abstract Objective Previous research has found an association between sleep problems and suicidal behavior. However, it is still unclear whether the association can be largely explained by depression. In this study, we prospectively examined relationships between sleep problems when participants were 12–14 years old and subsequent suicidal thoughts and self-harm behaviors—including suicide attempts—at ages 15–17 while controlling for depressive symptoms at baseline. Methods Study participants were 280 boys and 112 girls from a community sample of high-risk alcoholic families and controls in an ongoing longitudinal study. Results Controlling for gender, parental alcoholism and parental suicidal thoughts, and prior suicidal thoughts or self-harm behaviors when participants were 12–14 years old, having trouble sleeping at 12–14 significantly predicted suicidal thoughts and self-harm behaviors at ages 15–17. Depressive symptoms, nightmares, aggressive behavior, and substance-related problems at ages 12–14 were not significant predictors when other variables were in the model. Conclusions Having trouble sleeping was a strong predictor of subsequent suicidal thoughts and self-harm behaviors in adolescence. Sleep problems may be an early and important marker for suicidal behavior in adolescence. Parents and primary care physicians are encouraged to be vigilant and screen for sleep problems in young adolescents. Future research should determine if early intervention with sleep disturbances reduces the risk for suicidality in adolescents.
An innovative concept for acceleration of low-energy low-charge-state heavy-ion beams

Abstract A new accelerating structure called Hybrid RFQ (H-RFQ) is suggested. The structure consists of an alternating series of drift tubes (DTLs) and radio frequency quadrupole (RFQ) sections incorporated into one resonator. The proposed approach allows one to achieve twice as much average accelerating gradient compared to a conventional RFQ. A particular version of a 12.125 MHz H-RFQ has been developed for the Rare Isotope Accelerator (RIA) (Nolen, Nucl. Phys. A 734 (2004) 661–668; Ostroumov et al., Nucl Instr. and Meth. B 204 (2003) 433–439). A half-scale model of this structure has been built and studied to determine the final specifications for the full-power prototype. This paper presents comprehensive beam dynamics studies in a H-RFQ accelerating structure and experimental investigations of the 12.125 MHz H-RFQ model. Possible applications of H-RFQ structures are discussed.
The alternative antigen pathway

Abstract In this article, John Tew, Marie Kosco and Andras Szakal describe progress in deciphering a novel antigen pathway that represents an alternative to classical clearance by phagocytes. Upon booster immunization, immune complexes form rapidly and these complexes are handled not only by phagocytes but also by a series of non-phagocytic cells in a distinct pathway. Ultimately, immunogen in this alternative pathway is delivered to antigen-specific B cells in lymphoid nodules which process and present antigen to T cells. B cells obtain immunogen from follicular dendritic cells in the form of immune complex coated bodies or ‘iccosomes'. Antigen-specific B cells appear to find these newly discovered iccosomes especially palatable.
Experiencing the library in a panorama virtual reality environment

This paper investigates and illustrates the potential of using panorama virtual reality to enhance Web‐based library instruction. It describes a project in Sterling C. Evans Library at Texas A&M University that emulates a physical tour and renders it into an attention‐getting virtual tour with 360‐degree realistic views. The paper outlines three progressive developments in the use of tour as an instructional medium: the “physical tour”, the “Web virtual tour”, and the “virtual reality tour”. The project illustrates that panorama VR could be a powerful tool to combine the “physical tour” and the “Web‐based virtual tour” into one, making it a more useful medium that allows navigating, viewing, reading, hearing and remote access. The issues of design, hardware, software, and cost are addressed. The discussion also includes an overview of the Internet‐based VR technologies, a literature review of using VR technologies for learning and some considerations on future applications of panorama‐based virtual reality.
Metal-bis[poly(pyrazolyl)borate] complexes. Electrochemical, magnetic, and spectroscopic properties and coupled electron-transfer and spin-exchange reactions.

Electrochemical, magnetic, and spectroscopic properties are reported for homoleptic divalent (M = Mn, Fe, Co, Ni, Ru) and trivalent (M = Cr, Mn, Fe, Co) metal−bis[poly(pyrazolyl)borate] complexes, [M(pzb)2]+/0, where pzb- = hydrotris(pyrazolyl)borate (Tp), hydrotris(3,5-dimethylpyrazolyl)borate (Tp*), or tetrakis(pyrazolyl)borate (pzTp). Ligand field strengths in metal−pzb complexes increase as Tp* < Tp < pzTp, which reflects the importance of steric rather than electronic effects on spectroscopic properties. However, metal-centered redox potentials become more negative as pzTp < Tp < Tp*, which follows the electron-donating ability of the ligands. Co(III)/Co(II) and Mn(III)/Mn(II) electrode reactions are accompanied by a change in metal atom spin-state; i.e., (S = 0) [Co(pzb)2]+ + e- ⇆ (S = 3/2) [Co(pzb)2] and (S = 1) [Mn(pzb)2]+ + e- ⇆ (S = 5/2) [Mn(pzb)2]. Apparent heterogeneous electron-transfer rate constants derived from sweep-rate dependent cyclic voltammetric peak potential separations in 1,2-dich...
Crowding Induces Complex Ergodic Diffusion and Dynamic Elongation of Large DNA Molecules

Despite the ubiquity of molecular crowding in living cells, the effects of crowding on the dynamics of genome-sized DNA are poorly understood. Here, we track single, fluorescent-labeled large DNA molecules (11, 115 kbp) diffusing in dextran solutions that mimic intracellular crowding conditions (0–40%), and determine the effects of crowding on both DNA mobility and conformation. Both DNAs exhibit ergodic Brownian motion and comparable mobility reduction in all conditions; however, crowder size (10 vs. 500 kDa) plays a critical role in the underlying diffusive mechanisms and dependence on crowder concentration. Surprisingly, in 10-kDa dextran, crowder influence saturates at ∼20% with an ∼5× drop in DNA diffusion, in stark contrast to exponentially retarded mobility, coupled to weak anomalous subdiffusion, with increasing concentration of 500-kDa dextran. Both DNAs elongate into lower-entropy states (compared to random coil conformations) when crowded, with elongation states that are gamma distributed and fluctuate in time. However, the broadness of the distribution of states and the time-dependence and length scale of elongation length fluctuations depend on both DNA and crowder size with concentration having surprisingly little impact. Results collectively show that mobility reduction and coil elongation of large crowded DNAs are due to a complex interplay between entropic effects and crowder mobility. Although elongation and initial mobility retardation are driven by depletion interactions, subdiffusive dynamics, and the drastic exponential slowing of DNA, up to ∼300×, arise from the reduced mobility of larger crowders. Our results elucidate the highly important and widely debated effects of cellular crowding on genome-sized DNA.
Magnetooptical Materials for Integrated Nonreciprocal Devices

The growth of magnetooptical garnets with Ce and Bi substitution as well as magnetooptically active perovskites by pulsed laser deposition, and application to a monolithically integrated racetrack isolator, are described.
Zinnia marylandica (Asteraceae: Heliantheae), a new disease-resistant ornamental hybrid

Zinnia marylandica, an artificial hybrid betweenZ. angustifolia var.angustifolia (2n=22 female) andZ. violacea (2n=24, male), is described and illustrated.Zinnia marylandica is a stabilized amphiploid (2n=46) produced by colchicine-induced doubling of the sterile interspecific hybrids. It exhibits disease resistance to powdery mildew (Erysiphe cichoracearum), alternaria blight (Alternaria zinniae), and bacterial leaf and flower spot (Xanthomonas campestris pv.zinniae).