cssi/SciSciGPT-SciSciNet huggingface dataset:
Predicting task difficulty for different task types

This paper reports our investigation of differences in users' behavior between difficult and easy search tasks, as well as how these differences vary with different types of tasks. We also report how behavioral predictors of task difficulty vary across task types. In addition, we explored how whole-task-session level user behaviors and within-task-session level behaviors differ in task difficulty prediction. Data were collected in a controlled lab experiment with 48 participants, each completing 6 search tasks of three types: single-fact finding, multiple-fact finding and multiple-piece information gathering. Results show that task type affects the relationships between task difficulty and user behaviors and that prediction of task difficulty should take account of task type. Results also show that both whole-session level and within-session level user behaviors can serve as task difficulty predictors. Whole-session level variables show higher prediction accuracy, but within-session level factors have the advantage of enabling real-time prediction. These findings can help search systems predict task difficulty and adapt to users.
Cognitive biases in moral judgments that affect political behavior

Cognitive biases that affect decision making may affect the decisions of citizens that influence public policy. To the extent that decisions follow principles other than maximizing utility for all, it is less likely that utility will be maximized, and the citizens will ultimately suffer the results. Here I outline some basic arguments concerning decisions by citizens, using voting as an example. I describe two types of values that may lead to sub-optimal consequences when these values influence political behavior: moralistic values (which people are willing to impose on others regardless of the consequences) and protected values (PVs, values protected from trade-offs). I present evidence against the idea that voting is expressive, i.e., that voters aim to express their moral views rather than to have an effect on outcomes. I show experimentally that PVs are often moralistic. Finally, I present some data that citizens’ think of their duty in a parochial way, neglecting out-groups. I conclude that moral judgments are important determinants of citizen behavior, that these judgments are subject to biases and based on moralistic values, and that, therefore, outcomes are probably less good than they could be.
Comparative study of grid validation methods for wind load computations of transmission lines

Strong unsteady aerodynamic forces are generated by severe flow separations around transmission lines, and galloping can be induced by this inherent motive force. Due to the severe flow separations around transmission line with blunt cross-sections, transitions of boundary layers, and dissipations of vortex wakes, it is troublesome to calculate the wind load accurately. To account for the accurate computation of wind load for both single conductor and bundle conductor, comparative study of four different grid validation methods, including unsteady lift/drag forces, power spectral density (PSD) analysis of both lift/drag forces, wall shear stress on cylinder surface, unsteady turbulent kinetic energy in the flow field far down stream of the conductor cylinder, are conducted by solving Navier-Stokes equations. The results indicate that, it is feasible to employ the unsteady lift/drag force, PSD results of lift/drag forces to validate grid convergence of single conductor and wall shear stress is proposed to provide a more thorough insight into flow separation characteristics on cylinder surface; while besides the above three methods, the convergence of far field turbulent kinetic energy PSD results is as well proposed and then validated to be suitable for bundle conductors.
Molecular thermodynamics for salt-induce protein precipitation

In research laboratories and in the biotechnology industry, precipitation is commonly used to separate and isolate proteins from solutions. A molecular-thermodynamic model is developed for salt-induced protein precipitation, which considers on aqueous solution of globular protein molecules as a pseudo-one-component system containing macroions that interact through Coulombic repulsion, dispersion attraction and hydrophobic interactions, and forces arising from ion-excluded volume. Forces from ion-excluded volume take into account formation of ion pairs and ionic clusters at high salt concentrations; they are calculated in the context of the Percus-Yevick integral-equation theory. Hydrophobic interactions between exposed nonpolar amino-acid residues on the surfaces of the protein molecules are modeled as short-range, attractive interactions between ``spherical caps`` on the surfaces of the protein polyions. An equation of state is derived using perturbation theory. From this equation of state the authors calculate liquid-liquid equilibria: equilibrium between an aqueous phase dilute in protein and another aqueous phase rich in protein, which represents ``precipitated`` protein. In the equation of state, center-to-center, spherically symmetric macroion-macroion interactions are described by the random-phase approximation, while the orientation-dependent short-range hydrophobic interaction is incorporated through the perturbation theory of associating fluids. The results suggest that either ion-excluded-volume or hydrophobic-bonding effects can precipitate proteins inmore » aqueous solutions with high salt concentrations.« less
Characterization and Griwth of Oicanic Multiple Qanm Well Structures

Multiple quantum well structures consisting of alternating layers of two crystalline organic semiconductors, namely, 3,4,9,10 perylenetetracarboxylic dianhydride (PTCDA) and 3,4,7,8 naphthalenetetracarboxylic dianhydride (NTCDA), have been grown by organic molecular beam deposition. The layer thickness was varied from 10 to 200 A. Birefringence measurements indicate that there is a strong structural ordering in all PrCDA layers, although the PrCDA and NTCDA crystal structures are incommensurate. From optical absorption measurements, it is found there is a blue shift in the lowest energy PICDA singlet exciton line with decreasing layer thickness. A model based on exciton quantum confinement is proposed to explain the energy shift. We have measured the low temperature photoluminescence spectra of organic quantum well structures, and found a slight red shift in the spectra with decreasing well width. These results are also discussed.
New Perspective on Psychosocial Distress in Patients With Dysphonia: The Moderating Role of Perceived Control

Summary Objectives Although an association between psychosocial distress (depression, anxiety, somatization, and perceived stress) and voice disorders has been observed, little is known about the relationship between distress and patient-reported voice handicap. Furthermore, the psychological mechanisms underlying this relationship are poorly understood. Perceived control plays an important role in distress associated with other medical disorders. The objectives of this study were to (1) characterize the relationship between distress and patient-reported voice handicap and (2) examine the role of perceived control in this relationship. Study Design This is a cross-sectional study in a tertiary care academic voice clinic. Methods Distress, perceived stress, voice handicap, and perceived control were measured using established assessment scales. Association was measured with Pearson correlation coefficients; moderation was assessed using multiple hierarchical regression. Results A total of 533 patients enrolled. Thirty-four percent of the patients met criteria for clinically significant distress (ie, depression, anxiety, and/or somatization). A weak association ( r = 0.13; P = 0.003) was observed between severity of psychosocial distress and vocal handicap. Present perceived control was inversely associated with distress ( r = −0.41; P r = −0.30; P r = −0.30; P b for interaction term, −0.15; P Conclusions Severity of distress and vocal handicap were positively related, and the relation between them was moderated by perceived control. Vocal handicap was more related to distress among those with low perceived control; targeting this potential mechanism may facilitate new approaches for improved care.
Primary prostatic signet ring cell carcinoma

We report an uncommon case of primary prostatic signet-ring cell carcinoma which meets all criteria that define this clinicopathologic entity. Histologically, the tumor showed three different growth patterns, all of which contained large numbers of signet-ring cells. The predominant pattern, comprising approximately 50 percent of the tumor, was solid sheets of pure signet-ring cells. An intriguing finding was the presence of intestinal metaplasia involving the prostatic urethra and the large periurethral ducts. All mucin stains were intensely positive within the signet-ring cells and in the mucin lakes. Signet-ring cells stained positively for prostatic specific antigen, prostatic acid phosphatase, and carcinoembryonic antigen immunoperoxidase markers. Our patient presented with symptoms of urinary tract obstruction and locally widespread disease, infiltrating the rectum and the bladder, thus demonstrating the aggressive biologic behavior that traditionally has been ascribed to signet-ring cell carcinomas.
Hell's Angels and the Illusion of the Counterculture

L'A. soutient que l'association entre la contre culture americaine des annees 1960-70 (culture hippie, etc.) et le mouvement des Hell's Angel - association soutenue et mise en scene par la culture pop des les annees 1950 et de facon generale par la culture populaire de certains films et de la chanson - fut largement une illusion. Un apercu de l'histoire des Hell's Angels montre que les Angels, a l'exception de la periode des debuts du mouvement, partagaient et continuent de partager la plupart des caracteristiques de la technocratie, et non de la contre culture. Comme la technocratie, les Angels etaient obsedes par l'ordre, et la structure de leur organisation en temoigne. En fait, a l'epoque de la contre culture, les Hell's Angels mimaient la societe americaine dominante que la contre culture combattait energiquement et esperait eliminer. Ils ne partageaint pas la quete du mysticisme et de la spiritualite par la drogue pratiquee par la contre culture. Finalement, ils n'etaient pas des adeptes de l'individualisme - la raison principale de l'alliance initiale entre contre culture et Hell's Angels -, au contraire ils placaient le groupe au-dessus de l'individu.
Cell type-specific regulation of CREB gene expression: mutational analysis of CREB promoter activity.

Previous studies have shown that activation of the cyclic AMP (cAMP) pathway down-regulates CREB expression in CATH.a cells, an effect that appears to be mediated via inhibition of CREB gene transcription. In the current study, we compared this effect in CATH.a cells with regulation of CREB expression in another cell line, C6 glioma cells. In contrast to the findings in CATH.a cells, activation of the cAMP pathway up-regulates CREB expression in C6 glioma cells. To determine whether these opposite effects can be explained by regulation of CREB promoter activity, chloramphenicol acetyltransferase (CAT) assays were performed in CATH.a and C6 glioma cells that were transiently transfected with a CREB promoter-CAT fusion plasmid. Activation of the cAMP pathway decreased levels of CAT activity in transfected CATH.a cells but increased CAT activity in transfected C6 glioma cells. We next investigated the effect of mutations in the CREB promoter on such regulation in these two cell lines. Mutations of single CRE or Sp1 binding sites in the CREB promoter reduced basal levels of CAT activity but did not significantly attenuate regulation of the promoter in CATH.a or C6 glioma cells. However, mutation or deletion of two CRE sites in the CREB promoter completely abolished up-regulation of CAT activity in the C6 glioma cells and abolished basal levels of CAT activity in CATH.a cells. CREB promoter activity was also studied in cultured SHSY5Y cells and in primary cultures of striatal neurons as further comparisons. Activation of the cAMP pathway was found to increase CAT activity in both cell types. In the striatal cultures, this effect was obliterated by mutation or deletion of either of the two CREs in the promoter. These findings demonstrate cell type-specific effects of the cAMP pathway on CREB expression, which appear to be mediated via differential regulation of the CREB promoter.
The PEL1 Gene (Renamed PGS1) Encodes the Phosphatidylglycero-phosphate Synthase ofSaccharomyces cerevisiae

Phosphatidylglycerophosphate (PG-P) synthase catalyzes the synthesis of PG-P from CDP-diacylglycerol and sn-glycerol 3-phosphate and functions as the committed and rate-limiting step in the biosynthesis of cardiolipin (CL). In eukaryotic cells, CL is found predominantly in the inner mitochondrial membrane and is generally thought to be an essential component of many mitochondrial functions. We have determined that the PEL1gene (now renamed PGS1), previously proposed to encode a second phosphatidylserine synthase of yeast (Janitor, M., Jarosch, E., Schweyen, R. J., and Subik, J. (1995) Yeast 13, 1223–1231), in fact encodes a PG-P synthase of Saccharomyces cerevisiae. Overexpression of the PGS1 gene product under the inducible GAL1 promoter resulted in a 14-fold increase in in vitro PG-P synthase activity. Disruption of the PGS1 gene in a haploid strain of yeast did not lead to a loss of viability but did result in a dependence on a fermentable carbon source for growth, a temperature sensitivity for growth, and a petite lethal phenotype. The pgs1 null mutant exhibited no detectable in vitro PG-P synthase activity and no detectable CL or phosphatidylglycerol (PG); significant CL synthase activity was still present. The growth arrest phenotype and lack of PG-P synthase activity of a pgsA null allele ofEscherichia coli was corrected by an N-terminal truncated derivative of the yeast PG-P synthase. These results unequivocally demonstrate that the PGS1 gene encodes the major PG-P synthase of yeast and that neither PG nor CL are absolutely essential for cell viability but may be important for normal mitochondrial function.
Embedding reading comprehension training in content-area instruction

This study evaluated the effectiveness of comprehension training embedded in a program that taught science content to 2nd graders. The program included instruction about the structure of compare-contrast expository text, emphasizing clue words, generic questions, graphic organizers, and the close analysis of well-structured text exemplars. This program was compared with a program that focused on the science content but included no compare-contrast training as well as with a no-instruction control. Regular classroom teachers (14 from 4 schools), randomly assigned to treatment, provided the instruction; 215 students (7-8 years old) participated. The study replicated acquisition and transfer effects found in an earlier study, that is, transfer to compare-contrast text with content related and unrelated to the instructional content (with no loss in the amount of science content acquired). The program also led to better performance on written and oral response measures and on 1 of the 2 measures involving authentic (less well-structured) compare-contrast text. These findings support and extend previous findings that explicit instruction in comprehension is effective as early as the primary-grade level.
Effects of energy dissipation rate on islets of Langerhans: implications for isolation and transplantation.

Acute physical stresses can occur in the procurement and isolation process and potentially can contribute to islet death or malfunction upon transplantation. A contractional flow device, previously used to subject suspended cells to well-defined hydrodynamic forces, has been modified and used to assess the vulnerability of porcine islets of Langerhans to hydrodynamic forces. The flow profiles and velocity gradients in this modified device were modeled using commercial CFD software and characterized, as in previous studies, with the scalar parameter, energy dissipation rate (EDR). Porcine islets were stressed in a single pass at various stress levels (i.e., values of EDR). Membrane integrity, oxygen uptake rate, caspase 3/7 activity, and insulin release were not affected by the levels of fluid stress tested up to an EDR of 2 × 103 W/m3. Visual observation of the stressed islets suggested that cells at the islet exterior were peeled away at EDR greater than 10,000 W/m3, however, this observation could not be confirmed using image analysis software, which determined the ratio of surface perimeter to total area. The result of this study suggests an upper limit in fluid stress to which islets can be subjected. Such upper limits assist in the design and operation of future islet processing equipment and processes. Biotechnol. Bioeng. 2009;103: 413–423. © 2008 Wiley Periodicals, Inc.
Breast Cancer, Depression, Culture, and Marital Conflict:

Breast cancer is the most common form of cancer and the second leading cause of death in middle-age women. Several psychological, cultural, and systemic factors can exacerbate the course of this disease and complicate its treatment and recovery. These include clinical depression, cultural factors, and marital dynamics, particularly marital conflict. Individual and couples counseling can be essential for effective medical treatment and clinical outcomes. A case example illustrates these points.
Effect of cimetidine on digoxin kinetics and creatinine clearance.

infarction is not known. Moreover, the diagnosis of this arrhythmia should not be restricted to instances where delayed repolarization or extreme bradyarrhythmias are present. The therapeutic implications of this finding are unclear. Antiarrhythmic agents which potentially prolong the QT interval may be relatively contraindicated in this setting and the use of bretylium or early ventricular pacing may be preferable.
Protein-degrading enediynes: library screening of Bergman cycloaromatization products.

A screening method based on Bergman cycloaromatization products was applied to a compact library of estrogenic-enediyne hybrids. An enediyne candidate identified from the screen was subsequently synthesized, and it induced temperature- and concentration-dependent degradation of human estrogen receptor α upon cycloaromatization.
KINETICS OF FUROCOUMARIN PHOTOSENSITIZATION OF DNA TO NEAR‐ULTRAVIOLET RADIATION

— The kinetics of DNA photoadduct formation induced by irradiation with near-ultraviolet in the presence of furocoumarin photosensitizers has been analyzed for systems of differing repair competance and for light sources of arbitrary spectral intensity distributions. The results are exemplified by applications to published data on DNA photoadduct yields in vitro and in vivo and Escherichia coli survival curves.
Technical Note: DIRART – A software suite for deformable image registration and adaptive radiotherapy research

Purpose: Recent years have witnessed tremendous progress in image guide radiotherapy technology and a growing interest in the possibilities for adapting treatment planning and delivery over the course of treatment. One obstacle faced by the research community has been the lack of a comprehensive open-source software toolkit dedicated for adaptive radiotherapy (ART). To address this need, the authors have developed a software suite called the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART). Methods: DIRART is an open-source toolkit developed in MATLAB. It is designed in an object-oriented style with focus on user-friendliness, features, and flexibility. It contains four classes of DIR algorithms, including the newer inverse consistency algorithms to provide consistent displacement vector field in both directions. It also contains common ART functions, an integrated graphical user interface, a variety of visualization and image-processing features, dose metric analysis functions, and interface routines. These interface routines make DIRART a powerful complement to the Computational Environment for Radiotherapy Research (CERR) and popular image-processing toolkits such as ITK. Results :DIRART provides a set of image processing/registration algorithms and postprocessing functions to facilitate the development and testing of DIR algorithms. It also offers a good amount of options for DIR results visualization, evaluation, and validation. Conclusions : By exchanging data with treatment planning systems via DICOM-RT files andCERR, and by bringing image registration algorithms closer to radiotherapy applications, DIRART is potentially a convenient and flexible platform that may facilitate ART and DIR research.
Emotions Signal Authenticity: Understanding Lay Beliefs of Emotion and Altruism

Individuals in organizations are often motivated to appear altruistic. In the current research, we examine whether being emotional is an effective signal of altruistic character. Three studies find...
Continuous Absorption Due to Free-Free Transitions in Hydrogen

The absorption of radiation in the free-free transition of the negative hydrogen ion is the inverse process of bremsstrahlung from an electron in the vicinity of a neutral hydrogen atom. This process is the most important cause of continuous absorption by the atmosphere of the sun and stars in the infrared region. The transition matrix element is expressed, with sufficient accuracy, in terms of the $s$ phase shifts of electron-hydrogen atom scattering alone. To meet the requirement in astrophysical studies, the continuous absorption coefficients due to the free-free transition have been tabulated for a wide range of wavelengths (4050 A to infinity) and temperatures (2520 to 10 080\ifmmode^\circ\else\textdegree\fi{}K) of the hydrogen gas, by using the $s$ phase shifts of $e$-H scattering which include exchange and correlation effects between two electrons. The tabulated coefficients are 20-70% less than the ones computed by Chandrasekhar and Breen, who used Hartree functions without exchange. Further improvement of the present result is discussed.
Purification of rabbit uterine cytosolic estrogen receptors by affinity chromatography

Abstract Progress to elucidate the mechanism of estrogen action in uterine tissues has been hampered because of the formidable task of receptor purification. This report describes our recent success in the purification of ERc from estrogen-primed rabbit uterus. Crude cytosolic ERc are purified sequentially by affinity chromatography and gel filtration, using heparin-Sepharose 4B, 17β-estradiol-17-hemisuccinyl-oval-bumin-Sepharose 4B, and Sephadex G-50. This purified ERc sediments as a 4.5 S molecule on sucrose gradients in low-salt buffer, and exhibits a major radioactive peak in both polyacrylamide gel electrophoresis under nondenaturing conditions and in HPLC eluates. The radioactivity pattern in HPLC coincides with that of the u.v. scan, showing the elimination of other u.v. absorbing materials of the crude cytosol. These results show that the bulk of cytosolic proteins have been removed by this procedure and indicate the feasibility of using HPLC for the large scale purification and analysis of ERc. Attempts are initiated in this laboratory to produce antibodies against this purified receptor by hybridoma technique, and to further analyze the biochemical nature of the purified receptor.
Immunospecific staining of serologically-active lipids

Abstract The specificity of chromatographically separated lipids can be determined in situ and comparison made with other lipoidal materials under the same conditions. The method is simple, rapid, direct and useful for monitoring the serologic activity of materials during purification procedures.
Solution structure of the epsilon-aminohexanoic acid complex of human plasminogen kringle 1.

The solution structure of the human plasminogen kringle 1 domain complexed to the antifibrinolytic drug 6-aminohexanoic acid (ɛAhx) was obtained on the basis of 1H-NMR spectroscopic data and dynamical simulated annealing calculations. Two sets of structures were derived starting from (a) random coil conformations and (b) the (mutated) crystallographic structure of the homologous prothrombin kringle 1. The two sets display essentially the same backbone folding (pairwise root-mean-square deviation, 0.15 nm) indicating that, regardless of the initial structure, the data is sufficient to locate a conformation corresponding to an essentially unique energy minimum. The conformations of residues connected to prolines were localized to energetically preferred regions of the Ramachandran map. The Pro30 peptide bond is proposed to be cis. The ligand-binding site of the kringle 1 is a shallow cavity composed of Pro33, Phe36, Trp62, Tyr72 and Tyr74. Doubly charged anionic and cationic centers configured by the side chains of Asp55 and Asp57, and Arg34 and Arg71, respectively, contribute to anchoring the zwitterionic ɛAhx molecule at the binding site. The ligand exhibits closer contacts with the kringle anionic centers (∼0.35 nm average O…H distance between the Asp55/Asp57 carboxylate and ligand amino groups) than with the cationic ones (∼0.52 nm closest O…H distances between the ligand carboxylate and the Arg34/Arg71 guanidino groups). The ɛAhx hydrocarbon chain rests flanked by Pro33, Tyr64, Tyr72 and Tyr74 on one side and Phe36 on the other. Dipolar (Overhauser) connectivities indicate that the ligand aliphatic moiety establishes close contacts with the Phe36 and Trp62 aromatic rings. The computed structure suggests that the ɛAhx molecule adopts a kinked conformation when complexed to kringle 1, effectively shortening its dipole length to ɛ0.65 nm.
The reaction of cyclopropenyl cations with cyclopropenes

Cyclopropenes and biscyclopropenyl derivatives can be converted to substituted aromatic compounds by a variety of photochemical (l), thermal (le,2), anionic (b-2,3), and reductive (le,Jl) processes. Ne now report that substituted benzenes are also produced by the reaction of cyclopropenyl cations with cyclopropenes, a reaction pathway hitherto unrecognized. Hydride reduction of cyclopropenyl cations to cyclopropenes is well precedented (le,3,5). However, attempts to obtain the as yet unknown 1,2-diphenylcyclopropene (II) by this method have been singularly unsuccessful. Attempted reduction of 1,2-diphenylcyclopropenyl cation (I) under a variety of conditions gives 1,2,4,5_tetraphenylbenzene (III) as the sole characterizable product (6). The yields of III vary greatly (<5$ to lOO$) depending upon the conditions. For example, addition of NaBH4 in CH CN 3 to a solution of I in the same solvent affords III in quantitative yield. Winen the inverse addition is used, however, a complex mixture results and only minor amounts sf III are formed (< 5%). 3c4+ [v])Q( I II III The notion that the efficient formation of III in the first reduction is reaction of I with the cyclapropene II, as generated, is amply supported experiments below. due to by the
New electrodes for inert-gas welding arcs

WITH THE increased use of inert-gas arc welding, especially in automatic welding machines, problems of arc ignition and stability become important. New electrodes much more satisfactory than the conventional type have been developed by using the highly refractory oxides, thoria and zirconia, in combination with tungsten and other materials. The conventional welding electrode is of some nonconsumable material, usually tungsten, and starting is accomplished either by contact or by a high-frequency spark. When spark starting is used, ignition may be quite erratic, depending on the previous history of the tungsten electrode. If the electrode is cold, the arc may not form immediately or at all, and, when formed, it may be extremely mobile, with the footpoint moving rapidly over the tungsten surface. In an automatic setup, this type of behavior can lead to losses in both time and material. See Figure 1. This shows the effect on the work of slow starting and arc wander. Also, the welding torch may be damaged. With the new electrode, instant starting and a highly stable arc are obtained. The arc picks up at lower open-circuit voltage and the current ranges are extended.
Truncated Forms of the Dual Function Human ASCT2 Neutral Amino Acid Transporter/Retroviral Receptor Are Translationally Initiated at Multiple Alternative CUG and GUG Codons

The sodium-dependent neutral amino acid transporter type 2 (ASCT2) was recently identified as a cell surface receptor for endogenously inherited retroviruses of cats, baboons, and humans as well as for horizontally transmitted type-D simian retroviruses. By functional cloning, we obtained 10 full-length 2.9-kilobase pair (kbp) cDNAs and two smaller identical 2.1-kbp cDNAs that conferred susceptibility to these viruses. Compared with the 2.9-kbp cDNA, the 2.1-kbp cDNA contains exonic deletions in its 3′ noncoding region and a 627-bp 5′ truncation that eliminates sequences encoding the amino-terminal portion of the full-length ASCT2 protein. Although expression of the truncated mRNA caused enhanced amino acid transport and viral receptor activities, the AUG codon nearest to its 5′ end is flanked by nucleotides that are incompatible with translational initiation and the next in-frame AUG codon is far downstream toward the end of the protein coding sequence. Interestingly, the 5′ region of the truncated ASCT2 mRNA contains a closely linked series of CUG(Leu) and GUG(Val) codons in optimal consensus contexts for translational initiation. By deletion and site-directed mutagenesis, cell-free translation, and analyses of epitope-tagged ASCT2 proteins synthesized intracellularly, we determined that the truncated mRNA encodes multiple ASCT2 isoforms with distinct amino termini that are translationally initiated by a leaky scanning mechanism at these CUG and GUG codons. Although the full-length ASCT2 mRNA contains a 5′-situated AUG initiation codon, a significant degree of leaky scanning also occurred in its translation. ASCT2 isoforms with relatively short truncations were active in both amino acid transport and viral reception, whereas an isoform with a 79-amino acid truncation that lacked the first transmembrane sequence was active only in viral reception. We conclude that ASCT2 isoforms with truncated amino termini are synthesized in mammalian cells by a leaky scanning mechanism that employs multiple alternative CUG and GUG initiation codons.
Outcome after traumatic brain injury: Pathway analysis of contributions from premorbid, injury severity, and recovery variables

Abstract Novack TA, Bush BA, Meythaler JM, Canupp K. Outcome after traumatic brain injury: pathway analysis of contributions from premorbid, injury severity, and recovery variables. Arch Phys Med Rehabil 2001;82:300-5. Objective: To examine the relationship of premorbid variables, injury severity, and cognitive and functional status to outcome 1 year after traumatic brain injury (TBI) and to assess the feasibility of multivariate path analysis as a way to discover those relationships. Design: Prospective, longitudinal. Settings: Level I trauma center, acute inpatient rehabilitation hospital. Patients: One hundred seven subjects (87 men, 20 women; mean age, 33.91 ± 14.2 yr) who had experienced severe TBI, typically from motor vehicle crashes. Interventions: Acute medical and rehabilitation care. Main Outcome Measures: Disability Rating Scale, Community Integration Questionnaire, and return to employment. Evaluated in acute rehabilitation, and at 6 and 12 months' postinjury. Results: Path analyses revealed that premorbid factors had significant relationships with injury severity, functional skills, cognitive status, and outcome; injury severity affected cognitive and functional skills; and cognitive status influenced outcome. No significant relationships were found between injury severity and emotional status, injury severity and outcome, emotional status and outcome, and functional skills and outcome. Conclusions: Multivariate analysis is important to understanding outcome after TBI. Injury severity, as measured in this study, is less important to 12-month outcome than the premorbid status of the person and the difficulties (particularly cognitive deficits) exhibited at follow-up 6 months after the trauma.
Innovation in Curriculum: An Overview

Innovation in curriculum is gaining its thrust from a new set of value priorities—humanism, concern for racial and socioeconomic minorities, support of pluralism and diversity, increased interest in affective development, education for the very young, and legitimization of the search for value. These priorities are coupled with new understandings of how learning takes place, which cast the learner in an active, responsible, self-actualizing role and, at the same time, support the development of precise, highly organized sets of learning materials designed to achieve clearly defined objectives as efficiently as possible. Implications of these factors are examined in relation to curriculum design, instructional materials, professional roles, and the need for in-service education.
Ethanol exposure following unilateral entorhinal deafferentation alters synaptic reorganization in the rat dentate gyrus: A quantitative analysis of acetylcholinesterase histochemistry

Abstract The phenomenon of reactive synaptogenesis in the dentate gyrus following partial deafferentation was used to assess quantitatively the effects of ethanol exposure on neuronal plasticity. Adult male Long-Evans rats received unilateral lesions of the entorhinal cortex, followed by 40 days of dietary ethanol exposure. Synaptic reorganization of the commissural/associational ( C A ) and cholinergic (primarily septal) afferents was evaluated in the dentate gyrus processed for acetylcholinesterase (AChE) histochemistry. The widths and optical densities of several laminae in the molecular layer were measured using a computer-based digital imaging system. The degree of reorganization was assessed by comparing the lesioned side to the unlesioned side in each animal (difference scores were calculated). In the exposed blade of the dentate gyrus, the lesion-induced expansion of the C A width was reduced significantly in the ethanol group. However, in the buried blade, there was an actual shrinkage of the C A zone in the ethanol group. There was also a tendency for less “clearing” or lightening of the AChE staining in the C A zone of both blades. On the lesioned side, the ethanol group also displayed a significantly greater condensation or darkening of the AChE staining in the proximal outer molecular layer than the pair-fed control group. The supragranular layer of both blades ipsilateral to the lesion was reduced in width in the ethanol group. These results indicate that exposure to ethanol following partial deafferentation disrupts the normal pattern of synaptic reorganization in the dentate gyrus.
Early vs Delayed Vitamin A Supplementation in Very-Low-Birth-Weight Infants

The purpose of this trial was to test the hypothesis that vitamin A adequacy may decrease the incidence of bronchopulmonary dysplasia (BPD) in very-low-birth-weight infants. Serum vitamin A levels were measured and the effects of two regimens of vitamin A supplementation on the incidence of BPD were compared. There were 24 infants in each of two groups with a mean birth weight less than 1000 g, a mean gestational age of 27 weeks, and similar sexual and racial mixes. In group I, vitamin A levels were measured after 1 week of parenteral nutrition and, if low, the infant was given a 2000-IU supplement intramuscularly three times a week, beginning on the 10th to 14th day of life. In group II, the same supplementation was begun on the second to fourth day of life. In both groups, when enteral feedings reached 60 kcal/kg per day, 2500 IU/d vitamin A was given orally. The incidence of oxygen support at 28 days was similar in both groups, although in group II there was a trend toward less vigorous ventilatory support. chi 2 analysis showed that a significantly smaller proportion of infants in group II had BPD at 36 weeks' gestational age than in group I. Length of neonatal intensive care unit stay was significantly reduced from 81 to 60 days. We conclude that vitamin A supplementation should be administered early to small, premature infants who are at risk for BPD and that monitoring of plasma levels is essential.
IL-9 is associated with an impaired Th1 immune response in patients with tuberculosis.

Abstract Although a defective Th1 response has been demonstrated in patients infected with Mycobacterium tuberculosis ( Mtb ), the mechanisms leading to this defect are not well understood. To study the immune response to Mtb infection, we stimulated PBMC from individuals with latent tuberculosis infection (LTBI) or patients with tuberculosis (TB) with the Mtb specific antigen early secretory antigenic target-6 (ESAT-6). mRNAs for a panel of cytokines were measured using quantitative real-time PCR (qPCR). PBMC from TB patients exhibited low levels of IFN-γ, IL-12α, IL-12β, and IL-23 mRNA but high levels of IL-9 mRNA. Sera from TB patients blocked the differentiation and function of dendritic cells from TST negative (TST−) donors. Exogenous IL-9 reduced IFN-γ mRNA expression in PBMC from LTBI by 30% ( n = 4) and neutralization of IL-9 restored the IFN-γ mRNA expression in PBMC from TB patients by 66% ( n = 8). Thus, increased expression of IL-9 may contribute to the development of TB.
Use of a scanning optical profilometer for toolmark characterization

An optical profilometer has been used to obtain 3-dimensional data for use in two research projects concerning toolmark quantification and identification. In the first study quantitative comparisons between toolmarks made using data from the optical system proved superior to similar data obtained using a stylus profilometer. In the second study the ability of the instrument to obtain accurate data from two surfaces intersecting at a high angle (approximately 90 degrees) is demonstrated by obtaining measurements from the tip of a flat screwdriver. The data obtained was used to produce a computer generated "virtual tool," which was then employed to create "virtual tool marks." How these experiments were conducted and the results obtained will be presented and discussed.
Port-access coronary artery bypass with cardioplegic arrest: acute and chronic canine studies.

Background. Our goal is to perform minimally invasive coronary artery bypass grafting without sacrificing the benefits of myocardial protection with cardioplegia. Methods. Twenty-three dogs underwent acute studies and 4 dogs underwent survival studies. The left internal mammary artery was taken down using a thoracoscope. Cardiopulmonary bypass was conducted via femoral cannulas and using an endovascular balloon catheter for ascending aortic occlusion, root venting, and delivery of antegrade blood cardioplegia. Pulmonary artery venting was achieved with a jugular vein catheter. An internal mammary artery-to-coronary artery anastomosis was performed using a microscope through a 10 mm port. Results. All animals were weaned from cardiopulmonary bypass in sinus rhythm without inotropes. Cardiopulmonary bypass duration was 104 ± 28 minutes and aortic clamp duration was 61 ± 22 minutes. Cardiac output and pulmonary artery occlusion pressure were unchanged. The internal mammary artery was anastomosed to the left anterior descending artery (25) or the first diagonal (2) with patency shown in 25 of 27. One dog in the survival study had a very short internal mammary artery pedicle under tension and was euthanized for excessive postoperative hemorrhage. Three weeks postoperatively the remaining dogs had angiographically patent anastomoses, normal transthoracic echocardiograms, and histologically normal healing and patent grafts. Conclusions. Endovascular cardiopulmonary bypass using a balloon catheter is effective in arresting and protecting the heart to allow thoracoscopic internal mammary artery-to-coronary artery anastomosis.
Geologic controls of hydrothermal discharge on the northern Gorda Ridge

An investigation of a 10 x 10 km area near an axial high of the rift valley of the northern Gorda Ridge by using bathymetry, side-scan sonar, and bottom photography where prior water-column surveys indicated ongoing high-temperature hydrothermal discharge reveals that the discharge is localized by specific tectonic and volcanic conditions. The discharge occurs where faults having a predominant ridge-parallel and an anomalous subsidiary ridge-oblique tectonic trend intersect at the southern end of a linear ridge on the east wall and at another site at the base of the east wall of the rift valley. Hydrothermal alteration of basalt talus and stratiform hydrothermal precipitates produced by past activity occur where faults and fissures with the same two tectonic trends intersect near a fault having a third ridge-transverse trend at a 1 x 1 km zone of sheet flows on the floor of the rift valley. Present and past hydrothermal discharge in this area is controlled by the intersection of an axis-parallel tectonic trend common to all spreading centers having axis-oblique trends related to the regional stress field near the shallowest and volcanically most productive part of the ridge segment.
Phase Structural Transitions of Polyelectrolyte-Surfactant Complexes between Poly(vinylamine Hydrochloride) and Oppositely Charged Sodium Alkyl Sulfate

Synchrotron small-angle X-ray scattering was used to investigate the nanostructures of polyelectrolyte-surfactant complexes between linear poly(vinylamine hydrochloride) chains and oppositely charged surfactants of sodium alkyl sulfate (SC n S) at room temperature (∼23 °C). Both the pH variance of complexation and the surfactant tail length change could induce phase structural transitions. A novel phase structure of a 2D distorted hexagonal packing of deformed cylinders or ribbons with a = b and an enclosed angle θ larger than 120° was, for the first time, observed in polyelectrolyte-surfactant complexes at n = 11-12 and certain pH values. In sequence with increasing pH values of complexation between the PVACl and SC 11 S solutions from pH = 5.9 to pH = 12.0, the structures of 2D distorted hexagonal, bilayer lamellar, and 2D hexagonal close packing of cylinders were determined. When the pH values for complexation were fixed at 5.9 and 8.9, the decrease in carbon atom numbers of surfactant alkyl chains from n = 12 to n = 9 induced the same structural transition. This structural transition was caused by the increase in the ratio of the area of polar groups to the volume of alkyl chains of surfactants arranged inside the complexes, thus increasing the mean curvature at the polar/apolar interfaces of surfactant ions. The increase in surfactant tail length could also induce a lamellar structural transition. When the lamellar structure in complexes was formed by SC n S with n = 10 and 11, the alkyl chains of surfactant were fully extended and perpendicular to the lamellar surface, while when the lamellar structure in complexes was formed by SC n S with long tails of n = 14 and 16, the alkyl chains of surfactant were partially overlapped or tilted to the lamellar surface in the bilayer arrangement due to the stronger hydrophobic interactions.
Postglacial Vegetation and Fire History in the Chirripó Páramo of Costa Rica

Pollen and charcoal analysis of a 5.6-m sediment core from Lago de las Morrenas (9°29′N, 83°29′W; 3480 m) provides evidence of postglacial vegetation and fire history in the highlands of the Cordillera de Talamanca, Costa Rica. The site is presently surrounded by treeless paramo vegetation and apparently has been so since deglaciation about 10,000 yr B.P. Pollen spectra suggest no pronounced changes in vegetation since ice retreat. Fires set by people or lightning have burned the paramo repeatedly, with fire activity probably highest during the late Holocene, but these fires have not carved paramo from forest. Pollen percentages for Gramineae and other paramo taxa decline upward, whereas percentages for certain subalpine, lower montane, and lowland forest taxa increase slightly; these changes may reflect the impact of prehistoric human activity or slight upslope migrations of forest taxa owing to climatic warming. There is no clear evidence of higher timberlines during the mid-Holocene.
Geodetic sets in graphs

For two vertices u and v of a graph G, the closed interval I[u, v] consists of u, v, and all vertices lying in some u − v geodesic in G. If S is a set of vertices of G, then I[S] is the union of all sets I[u, v] for u, v ∈ S. If I[S] = V (G), then S is a geodetic set for G. The geodetic number g(G) is the minimum cardinality of a geodetic set. A set S of vertices in a graph G is uniform if the distance between every two distinct vertices of S is the same fixed number. A geodetic set is essential if for every two distinct vertices u, v ∈ S, there exists a third vertex w of G that lies in some u− v geodesic but in no x− y geodesic for x, y ∈ S and {x, y} 6= {u, v}. It is shown that for every integer k ≥ 2, there exists a connected graph G with g(G) = k which contains a uniform, essential minimum geodetic set. A minimal geodetic set S has no proper subset which is a geodetic set. The maximum cardinality of a minimal geodetic set is the upper geodetic number g(G). It is shown that every two integers a and b with 2 ≤ a ≤ b are realizable as the geodetic and upper geodetic numbers, respectively, of some graph and when a < b the minimum order of such a graph is b + 2.
CENTRAL VENTILATORY DYSFUNCTION IN MYELODYSPLASIA: AN INDEPENDENT DETERMINANT OF SURVIVAL

SUMMARY Central ventilatory dysfunction (CVD) is a significant complication of myelodysplasia with Arnold-Chiari type II defect. The records of 616 patients with myelodysplasia were reviewed and CVD was documented in 35 cases (5·7 per cent): it was the single most common cause of death in this population. There was no significant association between CVD and level of lesion, severity of hydrocephalus, hemorrhage or infection. The effects of CVD may be variable, with some patients having spontaneous remission and others having severe, often fatal, disruption of ventilation. RESUME Perturbation centrale de la ventilation dans les myelodysplasies: factuer independant de survie La perturbation centrale de la ventilation (CVD) est une complication significative des myelodysplasies avec Arnold-Chiari de type II. Les dossiers de 616 sujets myelodysplasiques ont ete analyses et la CVD retrouvee dans 35 cas (5,7 pour cent): il s'agissait de la cause unique de deces la plus habituelle dans cette population. II n'y avait pas de relation significative avec le niveau lesionnel, la gravite de 1'hydrocephalic une hemorragie ou une infection. Les effets de la CVD etaient variables, la remission spontanee ayant ete observee chez certains sujets, d'autres ayant presente une interruption grave, souvent mortelle, de la respiration. ZUSAMMENFASSUNG Zentrale Atemstorung bei Myelodysplasia: ein entscheidender Uberlebensfaktor Die zentrale Atemstorung (CVD) ist eine signifikante Komplikation der Myelodysplasie mit dem Arnold-Chiari Defekt Typ II. Die Krankenakten von 616 Patienten mit Myelodysplasie wurden durchgesehen und in 35 Fallen wurde eine CVD gefunden (5·7 Prozent): sie war die haufigste alleinige Todesursache bei dieser Gruppe. Es fand sich keine signifikante Beziehung zwischen CVD und Hohe der Lasion, Schwere des Hydrocephalus, Blutung Oder Infektion. Die Auswirkungen der CVD konnen unterschiedlich sein, bei einigen Patienten konnen spontane Remissionen eintreten und andere haben schwere, oft fatale Atempausen. RESUMEN Disfuncion ventilatoria central en la mielodisplasia: un determinate independia para la supervivencia La disfuncion ventilatoria central (DVC) es una complicacion significativa de la mielodisplasia con defecto de Arnold-Chiari del tipo II. Se revisaron las historias de 616 pacientes con mielodisplasia y se halo una DVC en 35 casos (5·7 por ciento): era la causa mas corriente de defuncion en esta poblacion. No habia asociacion significativa entre la DVC y el nivel de la lesion, la gravedad del hidrocefalo, la hemorragia y la infeccion. Los efectos de la DVC pueden ser variables, habiendo pacientes con remision espontanea, mientras que otros sufren una disrupcion de la ventilacion grave y a menudo fatal.