cssi/SciSciGPT-SciSciNet huggingface dataset:
Morphogenesis of intestinal villi. I. Scanning electron microscopy of the duodenal epithelium of the developing chick embryo

Development of villi in the duodenum of the chick was studied in stages ranging from 11 days of incubation to one week after hatching. Formation of definitive villi is preceded by development of a set of previllous ridges that run lengthwise along the duodenum. The first set of 16 previllous ridges (Set I) is complete by about 13 days of incubation; all ridges in the set are fairly uniform and proceed through their subsequent development in synchrony. Previllous ridges in Set I fold into a highly regular zigzag pattern between 14 and 16 days of incubation. Definitive villi develop from Set I ridges beginning at about 17 days when populations of distinct cells appear on the crests of the ridges between angles in the zigzag folds. Cells in these populations lack the rounded appearance of cells seen in earlier stages; their apical surfaces are densely covered with microvilli. A second set of villi (Set II) develops at about 16 days of incubation when about 16 rows of tongue-like flaps erupt between the previllous ridges of Set I. At hatching, Set II villi are still smaller than villi of Set I; this distinction disappears by about the fourth day after hatching. The significance of the morphological changes in epithelial cells is discussed in terms of several hypotheses bearing on the mechanisms of villus formation.
New Voices in the Public Sphere: A Comparative Analysis of Interpersonal and Online Political Talk

AbstractPolitical conversation for many people is a taboo activity, particularly with acquaintances or strangers. Online, there are a wealth of political conversation spaces, designed for acquaintances and strangers to interact. The question is are there people talking politics online who do not do so face-to-face. This essay presents findings on people’s reported political conversation behaviour online and offline from secondary survey analysis of a research project studying the effects of political deliberation. The survey analysis suggests that there are people who talk politics online who do not do so in face-to-face situations, and they are categorically different than those who do so face-to-face. The Internet may provide a new context for political conversation for those who would not normally engage in face-to-face political conversations, thus bringing new voices into the public sphere.
Rationale for intermittent nitrate therapy.

Abstract Tolerance to the pharmacologic and therapeutic effects of nitrate therapy is now well established. This phenomenon may be defined as either a decreased response to a given amount of nitrate or the need for an increased amount of nitrate to maintain a constant effect. Tolerance has been demonstrated with all forms of nitrate therapy that maintain continuous blood levels of the drug, including frequent oral dosing, constant intravenous infusion, and continuous transdermal delivery. It can develop rapidly after only a few doses of a nitrate preparation and tends to be partial rather than absolute. Strategies for the prevention of nitrate tolerance include the avoidance of maximum nitrate doses and the use of intermittent nitrate dosing regimens. Providing a relatively brief nitrate-free interval restores vascular responsiveness to nitrates, most likely due to a recovery of the metabolic mechanisms responsible for the therapeutic effect of these drugs. The duration of this period of nitrate abstinence varies, depending on the nitrate preparation used but is generally in the range of 8–12 hours. Such intermittent therapy not only reduces the risk of nitrate tolerance, but also provides a convenient approach to outpatient management.
Effect of F2 intensity on identity of /u/ in degraded listening conditions.

The current study investigated the influence of the second formant (F2) intensity on vowel labeling along a /u/-/i/ continuum. Twenty-two listeners with normal-hearing (NH) sensitivity and 14 liste...
The Psychometric Effects of Altering the Ceiling Criterion on the Passage Comprehension Test of the Woodcock Reading Mastery Tests- Revised/NU

The Passage Comprehension portion of the Woodcock Reading Mastery Tests - Revised/NU was administered to 63 middle school and high school students and scored according to the ceiling criterion recommended in the test manual (i.e., six consecutive errors). The protocols were then rescored using the following ceiling criteria: (a) five consecutive errors, (b) five errors in six consecutive responses, and (c) five errors in seven consecutive responses. A strong relationship was determined between raw scores obtained using all four scoring methods. An external measure, full scale intelligence quotient, was found to be consistently correlated between each group of raw scores. The number of items administered was reduced to a statistically significant degree by relaxing the ceiling criterion without negatively affecting the psychometric properties of the test. Regression equations were presented in order to create accessibility to the Woodcock Reading Mastery Tests - Revised/NU norm tables when using the altern...
Politics and priorities: placing gender in geographic education

Gender has long been implicated in geographic education, though generally implicitly until the late twentieth century. Emphasizing British and American examples, this paper examines gender representation among geographic educators, in student participation, and in learning. It then turns to pedagogical issues that arise as content and strategies relevant to gender themes are addressed in different temporal and place contexts. It concludes by identifying questions for further exploration.
Molecular Dynamics Modeling of the Mechanical Behavior of Metallic Multilayers

Constant-stress molecular dynamics simulations are used to study the mechanical properties of equal concentration Cu-Ni (111) metallic multilayers of repeat lengths 0.4--0.5 nm. Uniaxial stress is applied along the close-packed and perpendicular to the close-packed directions within the (111) plane. The observed elastic moduli do not display a supermodulus effect as observed in experimental bulge tests for the biaxial modulus. However, both the average interlayer spacing and the out-of-plane Poisson ratio display anomalous effects for multilayer repeat lengths below about two nanometers.
Effects of Ultrasound Frequency and Tissue Stiffness on the Histotripsy Intrinsic Threshold for Cavitation

Histotripsy is an ultrasound ablation method that depends on the initiation of a cavitation bubble cloud to fractionate soft tissue. Previous work has indicated that a cavitation cloud can be formed by a single pulse with one high-amplitude negative cycle, when the negative pressure amplitude directly exceeds a pressure threshold intrinsic to the medium. We hypothesize that the intrinsic threshold in water-based tissues is determined by the properties of the water inside the tissue, and changes in tissue stiffness or ultrasound frequency will have a minimal impact on the histotripsy intrinsic threshold. To test this hypothesis, the histotripsy intrinsic threshold was investigated both experimentally and theoretically. The probability of cavitation was measured by subjecting tissue phantoms with adjustable mechanical properties and ex vivo tissues to a histotripsy pulse of 1-2 cycles produced by 345-kHz, 500-kHz, 1.5-MHz and 3-MHz histotripsy transducers. Cavitation was detected and characterized by passive cavitation detection and high-speed photography, from which the probability of cavitation was measured versus pressure amplitude. The results revealed that the intrinsic threshold (the negative pressure at which probability = 0.5) is independent of stiffness for Young's moduli (E) <1 MPa, with only a small increase (∼2-3 MPa) in the intrinsic threshold for tendon (E = 380 MPa). Additionally, results for all samples revealed only a small increase of ∼2-3 MPa when the frequency was increased from 345 kHz to 3 MHz. The intrinsic threshold was measured to be between 24.7 and 30.6 MPa for all samples and frequencies tested in this study. Overall, the results of this study indicate that the intrinsic threshold to initiate a histotripsy bubble cloud is not significantly affected by tissue stiffness or ultrasound frequency in the hundreds of kilohertz to megahertz range.
P17.60NOVO-TTF 100A SYSTEM USED SUCCESSFULLY IN A PATIENT WITH A VENTRICULO-PERITONEAL SHUNT.

BACKGROUND: NovoTTF-100A system is a new modality of treatment approved for therapy of recurrent glioblastoma. Most patients with supratentorial tumors are eligible for therapy with the system, however, data on safety of this therapy in patients with intraventricular devices is very limited. METHODS: A 54-years old woman was originally diagnosed with oligodendroglioma WHO grade II 16 years ago. During the course of treatment she had 3 craniotomies for tumor resection, chemotherapy with 22 cycles of temozolomide, 2 cycles of PCV and radiotherapy, including stereotactic approach. Following her last resection, tumor specimen exhibited features of high-grade glioma with areas of high cellularity, microvascular proliferation and invasion of the leptomeninges. Patient's course was complicated by severe recurring cytopenias. She developed a subgaleal pseudomeningocele,following her last surgery which required placement of a ventriculo-peritoneal (VP) shunt with a non-programmable valve. At this stage her treatment options for progressive malignant glioma were very limited and we elected to use NovoTTF-100A system. RESULTS: The patient tolerated treatment well. There were no complications associated with the NovoTTF-100A system and VP shunt used concomitantly. Patients' pseudomeningocele responded very well to shunting and eventually resolved. Her compliance with NovoTTF-100A system was relatively low, averaging at 39.2%, nevertheless, after six months of therapy there was no radiographic evidence of disease progression. CONCLUSIONS: Based on this limited experience we conclude that NovoTTF-100A system can be safely used in patients with VP shunts and non-programmable valves. Moreover, encouraging progression free survival was seen in this patient with heavily pre-treated glioma using NovoTTF-100A system as a single modality.
Differences in trauma care among pediatric and nonpediatric trauma centers

To characterize pediatric trauma care, state trauma registry data from all designated trauma centers in Pennsylvania were divided into three categories, that from: (1) pediatric centers, (2) urban nonpediatric centers, (3) and rural nonpediatric centers. From October 1, 1986 through September 30, 1989 (3 years), 4,615 patients less than 15 years old were admitted to 28 trauma centers in Pennsylvania. Nonpediatric centers cared for the majority of children (2,734, 59.2%), but the average number of children treated per nonpediatric institution (105.1 per year) was far fewer than the average treated in the pediatric centers (940.5). Pediatric trauma centers in the state treated a younger population (6.4 +/- 4.2 years, mean +/- SD) compared with urban and rural nonpediatric centers (8.4 +/- 4.2 and 8.1 +/- 4.3 years, respectively; P less than .05). Pediatric centers received proportionately more children by transfer (56.2%), victims of falls (34.6%), pedestrian injuries (16.8%), and head and neck injuries (41.8%, all P less than .05). Nonpediatric centers received children directly from the scene of injury more frequently than transferred from other hospitals. The male:female sex ratio in urban nonpediatric centers was significantly higher (70.1%, P less than .05) than in the other two groups. Rural nonpediatric centers cared for a higher proportion of motor vehicle passengers (28.5%) and patients classified as "other" in the state registry, a category to which bicycle injuries are assigned (28.2%, P less than .05). Mortality was highest in rural nonpediatric centers (6.2%). The death rate in pediatric centers and urban nonpediatric centers were similar (4.1%) and significantly lower (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Delayed retention effect: Attention, perseveration, or both?

Abstract A widely accepted explanation of the delay retention effect (DRE) is the Kulhavy-Anderson (1972) interference-perseveration hypothesis. An alternative hypothesis is students pay less attention to immediate than to delayed feedback. The attention and interference-perseveration hypotheses were examined by comparing the DRE under typical conditions where subjects are presented with feedback and conditions where subjects were required to rerespond to items missed after receiving feedback. Consistent with the attention hypothesis, the response requirement substantially reduced the size of the DRE. In addition, contrary to what would be predicted from the interference-perseveration hypothesis, students in the immediate feedback conditions did not make more perseverative errors on the post-test than did students in the delayed feedback conditions. These results suggest that both attention and interference factors play a role in the DRE, but that attention factors play a more important role in producing the DRE than do interference factors.
Automatic discovery of query-class-dependent models for multimodal search

We develop a framework for the automatic discovery of query classes for query-class-dependent search models in multimodal retrieval. The framework automatically discovers useful query classes by clustering queries in a training set according to the performance of various unimodal search methods, yielding classes of queries which have similar fusion strategies for the combination of unimodal components for multimodal search. We further combine these performance features with the semantic features of the queries during clustering in order to make discovered classes meaningful. The inclusion of the semantic space also makes it possible to choose the correct class for new, unseen queries, which have unknown performance space features. We evaluate the system against the TRECVID 2004 automatic video search task and find that the automatically discovered query classes give an improvement of 18% in MAP over hand-defined query classes used in previous works. We also find that some hand-defined query classes, such as "Named Person" and "Sports" do, indeed, have similarities in search method performance and are useful for query-class-dependent multimodal search, while other hand-defined classes, such as "Named Object" and "General Object" do not have consistent search method performance and should be split apart or replaced with other classes. The proposed framework is general and can be applied to any new domain without expert domain knowledge.
A static optimal strategy for a service robot: a one dimensional case

Abstract In this paper we present a method for creating a strategy to control the movements of a service robot, servicing thread rewinding machines. The robot moves from one machine to another detecting a dropped or broken thread. When this is detected the robot will restart the machine. A previous paper considered a number of naive strategies and compared them to the simple strategy of just moving back and forth from one end of the line to the other. In this paper we will propose a new method for determining the strategy and we will examine the effects of this new strategy with the aid of simulation.
The Duration of a Nerve Root Compression Modulates Evoked Neuronal Responses in a Rat Model of Painful Injury

The annual incidence for neck pain in the adult population is 30–50% [1]. The cervical nerve roots are at risk for mechanical injury due to impingement of surrounding structures which can result in pain and numbness [2]. During nerve root compression, an immediate, brief increase in spontaneous afferent activity and a gradual decrease in electrically evoked axonal conduction have been reported [3,4]. Although previous studies demonstrate that a transient cervical nerve root compression induces persistent behavioral sensitivity [5,6], it is not known how the tissue mechanics during loading modulate neuronal function or how they relate to the onset of pain. Therefore, the goal of this study was to quantify neuronal activity in the spinal cord as a function of the duration of applied compression by measuring both electrically-evoked and spontaneous afferent activity during a transient compression of the cervical nerve root in a rat model of pain [5,6].Copyright © 2011 by ASME
Some Important Variables Related to Conservation Knowledge and Interest.

This study was an attempt to isolate and identify some important variables related to conservation knowledge and interest in high school age youth. The major goal of this study was to establish some basic variable groups that could provide additional meaning and direction for reintroducing an integrated conservation program into the secondary school curriculum through a more appealing instructional approach. Findings indicated that the assumption of a direct relationship between knowledge and interest does not necessarily hold. Findings also contradict popular assumptions regarding rural-urban, male-female, and age differences in levels of conservation knowledge and interest. Open-ended program approaches based on the variables identified could lead to improved methods for increasing conservation knowledge and interest.
Symbolic ethnicity and American Jews: The relationship of ethnic identity to behavior and group affiliation

Abstract Symbolic ethnicity is a variant of straight-line assimilation theory that predicts an attenuation of the connection between ethnic identity and both ethnic behavior and group affiliation, the result of persistent or heightened interest in the former and decline in the latter. This study utilizes survey data from a midwestern Jewish community to test this thesis. We do so in two stages. First, Cohen's typology of Jewish involvement is employed to assess levels of ethnic behavior and affiliation. Second, we attempt to determine whether manifestations of ethnic identity do or do not have behavioral and affiliative consequences. Our findings do not support the symbolic ethnicity argument.
Electron microscopic observations concerning the in vivo uptake and release of the agent of guinea-pig inclusion conjunctivitis (Chlamydia psittaci) in Guinea-pig exocervix

Abstract This report details electron-microscopical observations concerning C. psittaci infection in vivo. The model employed was that of the guinea-pig infected at the exocervical region with the agent of guinea-pig inclusion conjunctivitis (GPIC). Our observations indicate that chlamydial particles gain access to their target cells by the mechanism of endocytosis. Single GPIC elementary bodies were seen to be positioned within individual endosomes. The observations reported here provide evidence that chlamydial particles that had undergone their developmental cycle within the exocervical epithelial cells may leave the epithelium in 2 ways; within entire infected cells that had been shed into the lumen of the cervix and by means of the liberation of chlamydial particles from disrupted cells. The mechanism of cell disruption and shedding is thought to involve the large number of PMNs observed to be present within the enlarged intercellular spaces of the infected epithelium.
Prospective, Comprehensive Assessment of Cardiac Troponin T Testing After Coronary Artery Bypass Graft Surgery

Background— The significance and clinical role of cardiac troponin testing after coronary artery bypass grafting remain unclear. Methods and Results— Cardiac troponin T (cTnT) was measured during the first 24 hours after coronary artery bypass graft surgery in 847 consecutive patients. Only 17 patients (2.0%) had new Q waves or left bundle-branch block after surgery; however, cTnT elevation was observed in nearly all subjects, with a median cTnT concentration of 1.08 ng/mL overall. Direct predictors of postoperative cTnT values included preoperative myocardial infarction (P<0.001), preoperative intraaortic balloon pump (P<0.001), intraoperative/postoperative intraaortic balloon pump (P<0.001), number of distal anastomoses (P=0.005), bypass time (P<0.001), and number of intraoperative defibrillations (P=0.009), whereas glomerular filtration rate (P<0.001), off-pump coronary artery bypass grafting (P=0.003), and use of warm cardioplegia (P=0.02) were inversely associated with cTnT values. A linear associati...
Reaction of Anterior Pituitaries of Immature Female Rats to Injections of Various Amounts of Oestrin.

It is well established that injection of oestrin in normal female rats induces changes in the anterior hypophysis comparable to those of pregnancy and that such injections in castrated female rats ...
Whole body interaction for child-centered multimodal language learning

Children engage with the world with their whole bodies, and we suggest here that during dialect learning, as during other learning activities, technology be capable of responding in whole body ways. As the child becomes more engaged in a shared-reality environment, the coordination of the whole-body behaviors between the VP and child should increase, thereby enhancing the experience. In this paper, we present our work on developing a virtual agent that embodies whole-body behaviors and a shared-reality environment that encourages children to use whole-body expression in the context of learning dialect, and science talk.
Evidence for distinct metabolic utilization of stearic acid in comparison with palmitic and oleic acids in rats

Stearic acid, unlike other saturated fatty acids, is possibly hypolipidemic. The rate of plasma clearance and hepatic metabolism of stearic acid, as incorporated into chylomicron lipids, was compared with those of palmitic and oleic acids. Chylomicrons were specifically enriched and labeled in vivo with 14C-stearic acid (SA), palmitic (PA), or oleic acid (OA). Following intravenous injection of rats with labeled chylomicrons, the rates of plasma clearance and hepatic incorporation of the label in triglyceride (TG), phospholipid (PL), and other lipids were compared at 5-, 15-, and 30-min intervals. Stearic acid was cleared at the slowest rate (t12 = 19.7 min) compared with PA (t12 6.2 min) and OA (t12 = 8.1 min). At 30 min. only 68% of the SA dose was removed from the plasma, whereas most of PA (96%) and OA (92%) was cleared. SA and OA were removed by the liver at significantly slower rates compared with PA. At the peak (15 min) of plasma clearance, 17–18% of SA and OA were found in the liver, whereas 37% of PA was taken up by the liver. In the liver, 31.8% of the labeled SA and smaller fractions of PA (15.1%) and OA (6.8%) were present in PL. Conversely, less of the hepatic SA (31.4%) was found in TG, compared with PA (49.0%) and OA (60.4%) in the liver. No significant difference was noted in the relative distributions of 14C in cholesterol and other lipids. Conversion of SA to OA in the liver and intestine was minimal. The data provide new evidence that SA is released slowly from chylomicrons and preferentially utilized for PL synthesis in the liver. The results also suggest that OA is less contributory to hepatic lipogenesis because it is removed by the liver at a much slower rate and better utilized by the extrahepatic tissue than SA and PA. Among the three fatty acids compared, PA is most rapidly taken up and incorporated into TG in the liver. This may stimulate the hepatic synthesis of very low density lipoproteins, (VLDL), contributing to hyperlipidemia.
Multiband time-resolved spectra of metal surface plasmas: Comparison of experiment with plasma spectroscopic modeling

Summary form only given. In MTF liner compression experiments, MG magnetic fields heat up the inner liner surface during compression, possibly leading to gas or plasma formation and mixing of wall material with the fuel. To investigate the conditions leading to plasma formation from an inner metal liner surface, experiments have been performed on the 1-MA Zebra generator, by passing a fast-rising (1.1×1013 A/s rise rate) current through `barbell'-shaped aluminum (Al 6061) and copper (Cu 101) rods with diameters between 0.5 mm and 2 mm. The barbell shape avoids direct line-of-sight between arcs at contacts and the heated surface under investigation. Plasma formation is observed when the surface magnetic field approaches 2.2 MG for Al.1, 2, 3 The experiment also fulfills a need for detailed experimental data to benchmark radiation-MHD and plasma spectroscopy modeling. The metal plasma is well characterized by UV (266 nm) and visible (532 nm) 2-frame laser shadowgraphy, multi-frame optical imaging, filtered visible4 and EUV photometric measurements, and timeresolved visible and EUV spectroscopy. The magnetic field threshold for plasma formation, the expansion speed, the plasma temperature, and the emissions in visible and EUV bands have been compared with the results of a variety of numerical simulations, both Lagrangian and Eulerian, using several different sets of EOS, resistivity, and opacity tables.5,6 For the first time, a spectroscopic quality radiation transport line-of-sight integration for this Al plasma has been performed. Radiation-MHD modeling results from the MHRDR5 simulation is used as input for PrismSPECT spectral modeling. The line-of-sight integration takes into account the emission, absorption, and transmission of each plasma layer and finally is convoluted with the resolution of the EUV spectrometer. The resultant simulated spectrum compares well with the experimental EUV spectra.
The effects of mapping CT images to Monte Carlo materials on GEANT4 proton simulation accuracy.

Purpose : Monte Carlo simulations of radiation therapy require conversion from Hounsfield units (HU) in CT images to an exact tissue composition and density. The number of discrete densities (or density bins) used in this mapping affects the simulation accuracy, execution time, and memory usage in GEANT4 and other Monte Carlo code. The relationship between the number of density bins and CT noise was examined in general for all simulations that use HU conversion to density. Additionally, the effect of this on simulation accuracy was examined for proton radiation. Methods : Relative uncertainty from CT noise was compared with uncertainty from density binning to determine an upper limit on the number of density bins required in the presence of CT noise. Error propagation analysis was also performed on continuously slowing down approximation range calculations to determine the proton range uncertainty caused by density binning. These results were verified with Monte Carlo simulations. Results : In the presence of even modest CT noise (5 HU or 0.5%) 450 density bins were found to only cause a 5% increase in the density uncertainty (i.e., 95% of density uncertainty from CT noise, 5% from binning). Larger numbers of density bins are not required as CT noise will prevent increased density accuracy; this applies across all types of Monte Carlo simulations. Examining uncertainty in proton range, only 127 density bins are required for a proton range error of <0.1 mm in most tissue and <0.5 mm in low density tissue (e.g., lung). Conclusions : By considering CT noise and actual range uncertainty, the number of required density bins can be restricted to a very modest 127 depending on the application. Reducing the number of density bins provides large memory and execution time savings in GEANT4 and other Monte Carlo packages.
The information system design for the Flora North America Program

The Flora North America Program will create a computer data bank of taxonomic information about the vascular plants of North America north of Mexico. The system, which will serve a broad range of users, will provide for the acquisition, editing, and storage of data and the preparation of a variety of products. It will grow and evolve over a long period of time, continually incorporating changes to data and new categories of information as they become available. The system will utilize an existing computer program package, the IBM Generalized Information System (GIS), for creating, maintaining, querying, and generating reports from its files of data. In addition to a file of taxonomic, ecological, and geographic data about each taxon, the system will build and maintain a series of authority or dictionary files to control system content. The first major system product will be a published flora, generated by computer. Many other catalogs and indexes will be prepared and specific questions may be asked of the data bank to meet individual user needs for information.
Electrical terminal representation of conductor loss in transformers

The formulation of a general, complete electrical terminal representation of eddy-current loss in transformer windings is presented. It is shown that the effects of mutual resistances must be considered in addition to the familiar winding resistances (self resistances) for a complete description of eddy-current loss. A simple two-foil winding structure is analyzed to display the features of the self- and mutual-resistance terms. The example illustrates that leakage resistance, i.e. resistance associated with opposing winding currents of equal amp turns, provides only a partial description of eddy-current loss. The analysis is extended to multiple windings, with a simple three-foil winding structure as an example. >
Ionic Effects of Sodium Chloride on the Templated Deposition of Polyelectrolytes Using Layer-by-Layer Ionic Assembly

A new method for the patterning of ionic layer-by-layer assembled films with micron-sized features is presented. Self-assembled monolayers (SAMs) were used as templates to direct the deposition of sulfonated polystyrene (SPS) and poly(diallyldimethylammonium chloride) (PDAC) multilayers onto a surface. Both polyelectrolytes were assembled electrostatically from dilute solutions (10 and 20 mM on a repeat unit basis) with varying amounts of sodium chloride. The ionic content was varied from 0 to 4 M NaCl. The optimal conditions for templating were found at moderate salt contents. At high salt contents (≥1 M NaCl) the templating behavior of the chemically patterned SAM surface completely reversed due to electrostatic screening and dehydration of an oligo(ethylene glycol)surface, indicating that ionic strength can be used to dramatically alter polyion deposition behavior on the functionalized surface.
Lack of evidence for increased lipid peroxidation in ethanol-induced centrilobular necrosis of rat liver

— The pathogenetic role of lipid peroxidation in ethanol-induced liver injury was previously supported by demonstration of increased formation of diene conjugates and decreased hepatic levels of reduced glutathione in ethanol-fed animals and alcoholic patients with liver injury. The present study was carried out to investigate whether these findings can be extended to a rat model that was shown to produce a spontaneous ethanol-induced liver injury progressing from steatosis to necrosis and fibrosis (Hepatology6: 814, 1986). Despite the histological evidence of progression from hepatic steatosis to centrilobular necrosis in these animals, diene conjugate formation in mitochondrial and microsomal lipids was not enhanced when compared to pair-fed controls. In addition, hepatic levels of neither methionine nor glutathione were decreased in the ethanol-fed animals. The fatty acid composition of mitochondrial phospholipids from these animals was similar to that in the controls. However, in the microsomal phospholipids, the level of arachidonate (20:4) was depressed by about 50% as compared to the controls. These results demonstrate the lack of evidence for a pathogenetic relationship between lipid peroxidation and ethanol-induced liver injury progressing to centrilobular necrosis. They further suggest that the decreased levels of 20:4 commonly seen after chronic ethanol intake may not be due to a peroxidative loss.
Effect of increased dietary iodide on thyroid accumulation and secretion in euthyroid Arkansas subjects.

Thyroid function was investigated in 20 euthyroid Arkansas subjects during administration of daily iodide supplements of 0, 252 and 1009 μg I/day; a period of 13 weeks was allowed for equilibration at each higher dose level. Chemical assays and 131I counting methods were used to measure thyroidal and renal clearance rates, thyroidal accumulation of 127I and daily thyroxine turnover. The computed mean plasma iodide levels, σ, ranged between 0.008 and 0.03 μg/ml. With increasing iodide intake there occurred a significant decrease in thyroidal radioiodine clearance rate k1 and an increased thyroidal 127I accumulation, whereas thyroxine turnover rate remained substantially constant. When these results are considered together with those from publications of other investigators, the following relation appears to be valid for the average euthyroid subject over a wide range of iodide intake: 105 k1=22.8+0.254/σ. The presence of the constant term in this expression indicates that thyroidal 127iodide accumulation, ...
A Model for the Diffusion of Moisture in Adhesive Joints. Part I: Equations Governing Diffusion

Abstract A methodology is proposed to relate the diffusion coefficient of small penetrant molecules in polymers to temperature, strain, and penetrant concentration. The approach used is based on well-known free volume theories. It is assumed that the transport kinetics is governed by the constant redistribution of the free volume, caused by the segmental motions of the polymeric chains. An expression for the diffusion coefficient is inferred from the temperature, strain, and penetrant concentration dependence of the free volume. The stress dependence of solubility is predicted from the Hildebrand theory. It is shown that the resulting constitutive equations exhibit many features desirable for joint durability studies. Finally, a non-Fickian driving force arising from differential swelling is included in the governing equations.
Studies of the hexagonal model: An evaluation (or, the perils of stalking the perfect hexagon)

Abstract Stimulated by articles by Prediger and Vansickle (1992) , Fouad and Dancer (1992) , and Swanson (1992) , we assess the strengths and weaknesses of research using diverse populations to test Holland's (1985) hexagonal organization of vocational personalities and work environments and to apply it in practical applications. These articles and related literature generally support the hexagonal representation of interests for a variety of populations. We question whether further research that examines data from different groups for evidence of a hexagonal relation among interest measures is now as important as research on the effects of interest inventories on these groups or research that tests alternative ideas about presenting interest inventory results to counselors and their clients. A proposed new measure of congruence based on the angle between persons' or occupations' locations in two-dimensional space is critically examined, and an alternative congruence index is suggested.
Solid-phase peptide synthesis by ion-paired alpha-chymotrypsin in nonaqueous media.

Solid-phase synthesis of dipeptides in low-water media was achieved using AOT ion-paired alpha-chymotrypsin solubilized in organic solvents. Multiple solvents and systematic variation of water activity, a(w), were used to examine the rate of coupling between N-alpha-benzyloxycarbonyl-L-phenylalanine methyl ester (Z-Phe-OMe) and leucine as a function of the reaction medium for both solid-phase and solution-phase reactions. In solution, the observed maximum reaction rate in a given solvent generally correlated with measures of hydrophobicity such as the log of the 1-octanol/water partitioning coefficient (log P) and the Hildebrand solubility parameter. The maximum rate for solution-phase synthesis (13 mmol/h g-enzyme) was obtained in a 90/10 (v/v) isooctane/tetrahydrofuran solvent mixture at an a(w) of 0.30. For the synthesis of dipeptides from solid-phase leucine residues, the highest synthetic rates (0.14-1.3 mmol/h g-enzyme) were confined to solvent environments that fell inside abruptly defined regions of solvent parameter space (e.g., log P > 2.3 and normalized electron acceptance index <0.13). The maximum rate for solid-phase synthesis was obtained in a 90/10 (v/v) isooctane/tetrahydrofuran solvent mixture at an a(w) of 0.14. In 90/10 and 70/30 (v/v) isooctane/tetrahydrofuran environments with a(w) set to 0.14, seven different N-protected dipeptides were synthesized on commercially available Tentagel support with yields of 74-98% in 24 h.
The effect of cerulenin on the synthesis of the precursor gag polyprotein in defective murine leukemia and sarcoma virus producing cell lines.

Abstract The effect of cerulenin, an inhibitor of de novo fatty acid (and cholesterol) biosynthesis, on the synthesis of the precursor gag polyprotein, Pr65 gag in a defective murine leukemia virus (334C) producing cell lines (MJD-54, clone 2) the amount of the Pr65 gag remaining producing hamster cell line (HTG-2) was examined. In contrast to Moloney murine leukemia virus (M-MuLV) producing cell lines (MJD-54, clone 2) the amount of the Pr65 gag remaining in the presence of cerulenin (20 μg/ml) was greatly reduced in both defective virus-infected cells. This effect appears specific for the Pr65 gag polyprotein, since the env precursor polyprotein Pr80 env was normally synthesized and remained undegraded in cerulenin-treated 3JE-infected cells. Thin-section electron micrographs showed an increased accumulation of virion particles in vesicles of treated HTG-2 cells.
Selection algorithm for posterior versus lateral approach in laparoscopic adrenalectomy

Background There are no objective selection criteria described in the literature for the laparoscopic posterior retroperitoneal (PR) versus lateral transabdominal (LT) approach in a given patient. The aim of this study is to quantify the algorithm we have been using in our practice. Methods Within 11 years, 219 patients underwent laparoscopic adrenalectomy at one institution. The laparoscopic LT technique was used in patients with unilateral tumors >6 cm. In those patients with unilateral tumors Results Fifty-two patients underwent laparoscopic LT and 30 patients underwent PR adrenalectomy. Patients were selected for the PR approach if the distance from Gerota’s fascia to the skin was less than 5 cm and the 12th rib was at or rostral to the level of renal hilum. On multivariate analysis, total operative time correlated with body mass index in the LT approach and thickness of the perinephric fat and the distance between the adrenal tumor and the upper pole of kidney in the PR approach. Conclusion In this study, we have described an objective algorithm that can be used to select patients with unilateral adrenal tumors
A micromethod for the measurement of acetyl phosphate and acetyl coenzyme A

Abstract A method for the determination of acetyl phosphate in cell-free extracts is described. The sensitivity of this method is 20 pmol/ml of extract. An adaptation that permits the measurement of picomole quantities of acetyl CoA is also presented.
Identification of domains conferring G protein regulation on inward rectifier potassium channels.

Abstract Cardiac m2 muscarinic acetylcholine receptors reduce heart rate by coupling to heterotrimeric (αβγ) guanine nucleotide-binding (G) proteins that activate I KACh , an inward rectifier K + channel (IRK). Activation of the GIRK subunit of I KACh requires G βγ subunits; however, the structural basis of channel regulation is unknown. To determine which sequences confer G βγ regulation upon IRKs, we generated chimeric proteins composed of GIRK and RB-IRK2, a related, G protein-insensitive channel. Importantly, a chimeric channel containing the hydrophobic pore region of RB-IRK2 joined to the amino and carboxyl termini of GIRK exhibited voltage and receptor-dependent activation in Xenopus oocytes. Furthermore, carboxy-terminal sequences specific to this chimera and GIRK bound G βγ subunits in vitro. Thus, G βγ may regulate IRKs by interacting with sequences adjacent to the putative channel pore.
Structure of the Bradyrhizobium japonicum gene hemA encoding 5-aminolevulinic acid synthase.

Abstract The nucleotide (nt) sequence of the hemA gene, which encodes 5-aminolevulinic acid synthase (ALAS) from the bacterium Bradyrhizobium japonicum, is presented. This sequence predicts a protein of 408 amino acids (aa) with an Mr of 44 599. This predicted amino acid sequence is highly homologous to that of the chicken embryonic liver ALAS, exhibiting a 48.8% identical amino acid sequence over the entire length of the bacterial protein. A single mRNA start point was demonstrated by S1 protection analysis for the B. japonicum hemA. The 5' end of the transcript is 100 nt upstream from the start codon. The sequence of the promoter region has some sequence homology to the −35 nt region of the Escherichia coli consensus promoter sequence but not to the −10 nt region. There is also one block of 9 nt found in both the B. japonicum glnA and hemA promoter regions.
A Monte Carlo Simulation for the Effect of Compression on an Amorphous Polyethylene Melt in Very Thin Confined Geometry

The effect of compression on a melt composed of 20 chains of C 120 polyethylene between two impenetrable solid walls has been studied by a Monte Carlo simulation on a high coordination lattice. The compression is controlled by changing the wall separation between two plates in the confined geometry from ∼3R g to ∼2R g , which produced the overall densities ranging from 0.70 to 0.95 g/cm 3 . The density near the walls increases with the compression, which is attributed to an increase of the trans conformation. The effect of the local conformational change near the walls is delivered into the middle region with an oscillation of the bead density profile and an increase of the gauche conformation. For the molecular shape, anisotropy is observed in the whole region of the confined geometry, and the extent of the anisotropy is larger near the interfacial area. The more ordered structure at small scale is observed at the higher compression and the lower temperature. The short time center-of-mass diffusivity along the direction parallel to the wall is much more suppressed than the perpendicular component with the compression, though the parallel component is always larger than the normal component at a specific compression.
Contextual influences on interactive processing: effects of discriminability, quantity, and uncertainty.

Three contextual factors—(1) the discriminability of stimuli in pitch, (2) the number of stimuli differing in pitch, and (3)the uncertainty regarding which stimuli or tasks would appear—were manipulated as subjects performed speeded loudness classifications in each of six experiments. The magnitude of Garner interference and effects of congruity were used to gauge the degree of interactive processing. Enhancing pitch discriminability caused monotonic increases in interference and congruity. Stimulus-task uncertainty mediated the changes in Garner interference wrought by increased discriminability. Uncertainty also caused a surprising shift in congruity from strongly positive to strongly negative as uncertainty grew. Increasing stimulus quantity lowered interference, but had inconsistent effects on congruity. Regression analyses suggested that, collectively, these three contextual variables underlie most failures of selective attention in speeded classification.
Amnesia: Tests of the effect of delayed footshock-electroconvulsive shock pairings

Abstract In several recent studies in which temporal relations of a footshock or a conditioned stimulus and electroconvulsive shock were varied, results have been obtained which support either a proactive or a reactivation explanation of the results of memory consolidation experiments. In one of these experiments, delayed footshock-electroconvulsive shock pairings produced amnesia at a time after learning when the memory trace is usually not susceptible to disruption. In the studies reported here, Experiment 1 repeated the essential features of an experiment providing evidence for such delayed amnesia; Experiment 2, involving some modifications of the previous study, was also designed to study such effects. No delayed amnesia was found in these experiments and this argues against either the proactive or reactivation hypotheses.
A review of the ISEE-3 Geotail magnetic field results☆

This review presents a summary of past work on the ISEE-3 distant tail magnetic field observations. An attempt has been made to bring the many results together as a coherent whole, in the hope that the reader can envision the direction of future research necessary to achieve an understanding of the dynamics of the magnetotail from 60 to 240 earth radii and perhaps beyond.
A Multiphase-Dual Algorithm for the Zero-One Integer Programming Problem

Following a line of approach recently applied to the 0-1 integer programming problem with some success by Egon Balas, the algorithm of this paper is based upon an underlying tree-search structure upon which a series of tests is superimposed to exclude large portions of the tree of all possible 0-1 solutions from examination. In our method, the specific design of the enumeration and tests, supplemented by the use of a special type of constraint called a "surrogate constraint," results in an algorithm that appears to be quite efficient in relation to other algorithms currently available for solving the 0-1 integer programming problem. Early indications of efficiency must, however, be regarded as suggestive rather than conclusive, due to the limited range and size of problems so far examined. Following the analytical development of the method, three example problems are solved in detail with the Multiphase-Dual Algorithm to illustrate various aspects of its application. An extension of the algorithm to the general integer programming problem in bounded variables is briefly sketched in a concluding section.
PARAS: interactive parameter space exploration for association rule mining

We demonstrate our PARAS technology for supporting interactive association mining at near real-time speeds. Key technical innovations of PARAS, in particular, stable region abstractions and rule redundancy management supporting novel parameter space-centric exploratory queries will be showcased. The audience will be able to interactively explore the parameter space view of rules. They will experience near real-time speeds achieved by PARAS for operations, such as comparing rule sets mined using different parameter values, that would otherwise take hours of computation and much manual investigation. Overall, we will demonstrate that the PARAS system provides a rich experience to data analysts through parameter tuning recommendations while significantly reducing the trial-and-error interactions.
An historical perspective on hypersonic aerodynamic research at the Langley Research Center

The 40-year history of hypersonic technology is reviewed from a technical perspective. A broad overview is first given of the major accomplishments of hypersonic flight projects and systems studies that have been conducted over the last 40-odd years. Then, the history of major supersonic and hypersonic ground facilities at the NASA Langley and Ames Research Centers is traced, and some of the research conducted in them over the past 40 years is reviewed.
Visually directed pointing as a function of target distance, direction, and available cues*

In pointing at visual targets without sight of the hand, large errors occur. There is a tendency to overreach targets, and this tendency is much greater (about 25 cm) when convergence is the only cue to distance than when there are many cues (2 to 11 cm). Angular errors of up to 10 deg also occur. These tend to be to the side opposite the sighting eye, when the favored hand is used. The variance of the pointing response with convergence alone is reduced by approximately half with the introduction of several spatial cues. These results are interpreted as indicating that, for a target within the reach of the arm and with convergence alone as a cue, the depth signal produced by the visual system corresponds to a greater distance than that produced when many cues are available. The results are also consistent with the hypothesis that perceived direction tends to approximate direction from the sighting eye.