cssi/SciSciGPT-SciSciNet huggingface dataset:
The determinants of exploration and neophobia

Abstract The literature dealing with the factors that determine approach and avoidance responses to novelty is reviewed and evaluated and suggestions for further clarifying research are incorporated. Only those studies that measure exploration in a choice-type task are included because of the interpretive difficulties associated with forced-exploration tasks (e.g., the open-field). The determinants that are reviewed include changes in stimulus novelty and changes in responsiveness independent of stimulus novelty. The latter factors include physiological variables such as lesions and drugs. The juxtaposition of some recent data with older findings has helped to reveal similarities that may reflect the presence of similar underlying mechanisms. The status of the concepts of optimal arousal level and adaptation level is briefly discussed and it is concluded that they are incapable of encompassing the range of data available. In addition, some methodological issues are considered and it is concluded that concentration on the results of choice-type tasks has helped resolve some of the inconsistencies and ambiguities that had arisen through the use of forced-exploration tasks. The necessary requirements for the demonstration of flavor neophobia are also discussed.
Embryonal adenocarcinomas (a type of malignant teratoma) of the sacrococcygeal region. Clinical and pathologic aspects of 21 cases

Sacrococcygeal teratomas in 21 consecutive patients admitted to Memorial Hospital were all embryonal adenocarcinomas having a common histologic appearance. Seventeen of the patients were female, and all except one were Caucasians. The average age at diagnosis was 2 years, and the average survival after diagnosis was 1 year, with a range of 1 to 68 months. All had large presacral tumors, but 2 had no external deformity. Seven had a midline external protuberance, and 12 presented with enlargement of a buttock. Prior to diagnosis, in 12 patients, the primary tumor produced one or more of a symptom triad of constipation, urinary frequency, and lower extremity weakness, and, in 12 patients, the tumor had metastasized. The primary tumor was resected in 6 patients but recurred in 4 of the 5 patients surviving the operation. Eighteen patients received radiation therapy to the primary tumor and/or metastases, and tumor regression occurred in all. Regression was also obtained in several patients who received chemotherapy. Because of the large size of the tumors and the metastases present at the time of diagnosis at a relatively young age, it is likely that the tumors were present in the presacral space at birth. The failure of surgery to cure the tumors in this series and tumor sensitivity to radiation and chemotherapy suggest that their treatment should consist of a combination of therapeutic modalities.
False security: North Carolina sexual offenders' perceptions of residence restrictions

Despite increasingly restrictive sexual offender legislation from 1994 until 2006, there is little evidence that these laws are reducing the number and severity of sexually motivated crimes. This study used a nonrandom sample of 231 adult sexual offenders from 11 outpatient treatment sites and assessed their experiences with residence restrictions in the state of North Carolina. Results indicate sexual offenders face emotional and financial difficulties as a result of residence restrictions, even in a state where restrictions are less stringent. Young adults, in particular, had difficulty securing housing and were often unable to live with supportive family members. Overall, sexual offenders believed residence restrictions do nothing to prevent recidivism.
Casein maps: Effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles

Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80% ethanol (vol/vol) and 2 and 10mM calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (>1,000 nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80% induced the dissociation ( 8) in imidazole buffer. In addition, higher concentrations of casein (0.25mg/mL) and calcium (20mM) caused the formation of larger aggregates (>1,000 nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1mg/mL) and calcium (2mM). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature.
SITE SPECIFIC INCORPORATION OF 6-AZAURIDINE INTO THE GENOMIC HDV RIBOZYME ACTIVE SITE

The HDV ribozyme is proposed to catalyze its self cleavage reaction by a proton transfer mechanism wherein the N3 of its C75 acts as a general acid. The C75 to U mutation, which raises the N3 pKa from about 4 to almost 10, abolishes all enzymatic activity. To test if a U analogue with a neutral pKa can restore ribozyme function we incorporated 6-azauridine (n6U), a uridine analogue with histidine-like N3 pKa, into the genomic HDV ribozyme active site by 2′-O-ACE oligoribonucleotide protection chemistry. The resulting ribozymes were analyzed for their ability to undergo the HDV ribozyme cis-cleavage reaction. Incorporation of n6U at nucleotide position 75 did not restore ribozyme function compared to the U75 mutant. This suggests that the HDV ribozyme reaction mechanism involves more than positioning of a neutral nucleobase at the active site and implies that the exocyclic amino group of C75 participates in establishing the proper active site fold.
THE EFFECT OF CASH FLOW AND CREDIT CONSTRAINTS ON FINANCIAL FEASIBILITY AND STOCKING STRATEGIES ON U.S. CATFISH FARMS: A MIXED-INTEGER MULTI-STAGE PROGRAMMING APPROACH

The availability of credit for aquaculture businesses historically has been problematic in the U.S., but little attention has been paid in the aquaculture economics literature to effects of restricted credit and cash flow deficits on the feasibility and optimal management of fish farms. An existing multi-stage mathematical programming model of catfish production was extended to include cash flow, lending and repayment constraints and activities for various farm sizes and levels of equity. Cash flow constraints affected the optimal management plan for catfish farms, with greater changes occurring in the optimal plans for smaller farms. Smaller farms generally were affected more severely than larger farms by restricted access to capital. Sales restrictions (that reduce cash inflow due to a decrease in sales) of only 5% caused small farms to become infeasible (when debt servicing of long-term debt was considered), while the largest farm sizes considered could withstand only a 20% reduction in sales before be...
Cognitive Demand and Self-Presentation Efforts: The Influence of Situational Importance and Interaction Goal

The present study hypothesized that situational importance and social interaction goals influence people's self-presentation efforts and consequently their use and recall of dissembled information. Participants in an initial experimental phase were covertly videotaped conversing with a partner. During a second phase, participants completed questionnaires, created from verbatim transcripts of the interaction, which listed every statement participants made during their initial conversation. The questionnaires required participants to first indicate whether they did or did not make each statement and then to indicate the veracity of each statement. Results supported the hypothesis that self-presentation efforts (untruthful statements) and the number of unrecalled untruthful statements significantly increased during high-importance situations when the goal to make a competent impression was salient.
Turbulence modelling for active flow control applications

Steady and unsteady Reynolds-Averaged Navier-Stokes (RANS) computations are commonly performed for active flow control applications. This article reviews several recent results, and describes both numerics and physics-related issues. Specific turbulence modelling needs are pointed out that must be addressed in order for RANS to remain competitive with eddy-resolving simulations for flow control applications in the future.
MORMON PERCEPTION AND SETTLEMENT

ABSTRACT The distribution of Mormon settlements in the Great Basin is the result of the environmental perception of the Mormon leaders. The leaders selected the Salt Lake Valley as a destination on the basis of reports of explorers, and their perception of the region was formed before they ever saw the West. The central feature of the leaders'perception was the idea that the division between the then Oregon and California territories at the 42 parallel marked a climatic divide. Believing it was too cold for crops north of that boundary, Mormon leaders directed their settlement efforts southward from the Salt Lake Valley for three decades. Because the regions to the south were arid and only marginal for settlement, the leaders faced a constant struggle in convincing migrants they should attempt their settlement. To convince prospective settlers that they could successfully occupy the marginal sites of the Southwest, the leaders in their public statements transformed the Mormon perception of the Salt Lake V...
Attitude processing strategies

Several models of memory-based attitude processing were examined in a laboratory experiment. After receiving stimulus information with implications for either one or both of two attitudes (toward a person and toward a behavior with respect to this person), subjects were asked to recall the information and to report their attitudes. Information was received under instructions to form only one of these two attitudes. Consistent with past research, information was subsequently better recalled when it had implications for the attitude being evaluated than when it did not. However, null effects of the instructional set on reported attitudes suggested that subjects relied on their memory-for-attitude (or additional implications) rather than on memory-for-facts. The present findings extend the generality of this conclusion to behavioral attitudes, large stimulus sets, and heterogeneous stimulus items. Low correlations between recalled stimuli and reported attitudes also supported a memory-for-attitude model. However, correlations between behavioral attitudes and recall of behavioral outcomes increased under certain conditions. Results are discussed in relation to recent findings in person perception research.
Hydrostatic pressure effects on the superconducting properties of Ag1−xSn1+xSe2

Abstract The superconducting transition temperature, T c , of NaCl structure compounds in the series Ag 1−x Sn 1+x Se 2 is found to be exceptionally sensitive to hydrostatic pressures up to 21 kbar. For five samples of varying composition, T c is suppressed smoothly at a rate of −(6−8)×10 −5 K·bar −1 . These results are discussed with respect to the volume sensitivity of the electron-phonon interaction responsible for superconductivity.
S-N Curve inversion of a nickel-base superalloy at elevated temperature

Stress controlled tensile fatigue behavior of a representative nickel-base superalloy, Udimet 115, was studied at 760 °C and at 1 Hz while holding the maximum stress constant. An inversion in the S-N curve was observed within 104 cycles, in contrast to normal S-N behavior at ambient temperatures. A detailed analysis of the strain response to a trapezoidal applied stress waveform indicated that the inversion is consistent with increasing creep strains due to increasing mean stresses. Fractographic observations were also found to be consistent with the inversion in that, at higher mean stresses, intergranular fracture replaced the usual stage II-type intragranular fracture associated with fatigue failure in these planar-slip alloys. The results are also discussed with respect to the three regimes of dynamic creep and the observed plastic increments and anelastic strains.
On the fixation probability of a gene under random fluctuations in selection intensities in small populations.

A population with N monoecious individuals, and having two alleles, is considered. The problem of calculating the fixation probability of a particular allele under random fluctuation of selection intensities is re-examined, employing finite Markov chain methods. An approximate but general expression for this probability is obtained and the results obtained by previous workers are shown to be special cases of this result.
A Study of Planetary Waves in the Southern Winter Troposphere and Stratosphere. Pad II: Life Cycles.

Abstract Large-amplitude planetary waves in the southern winter stratosphere are observed to occur episodically, the result of episodic tropospheric forcing. This work is an observational study of the dynamics of the planetary waves, focusing on the evolution through a typical life cycle. Time lag correlations of wave amplitude with the Eliassen-Palm flux vector reveal the characteristic heat and momentum flux patterns associated with wave evolution. Energetic studies clearly show that the stratospheric waves can be understood in terms of a life cycle of vertical propagation from the troposphere, followed by decay from barotropic interactions with the zonal mean flow. Although usually of secondary importance baroclinic decay of stratospheric wave energy is also observed, resulting from equatorward heat flux in the lower stratosphere. Good agreement in the energy balances discounts in situ instability in the stratosphere as a source of wave activity. An average or composite over several clearly propagating...
Assessing the Usability of Human-Computer Interfaces

Engineers may be able to design a better interface if they take into account the control structures underlying the interface syntax.
Navier-Stokes prediction of a delta wing in roll with vortex breakdown

The three-dimensional, Reynolds-averaged, Navier-Stokes (RANS) equations are used to numerically simulate vortical flow about a 65 degree sweep delta wing. Subsonic turbulent flow computations are presented for this delta wing at 30 degrees angle of attack and static roll angles up to 42 degrees. This work is part of an on going effort to validate the RANS approach for predicting high-incidence vortical flows, with the eventual application to wing rock. The flow is unsteady and includes spiral-type vortex breakdown. The breakdown positions, mean surface pressures, rolling moments, normal forces, and streamwise center-of-pressure locations compare reasonably well with experiment. In some cases, the primary vortex suction peaks are significantly underpredicted due to grid coarseness. Nevertheless, the computations are able to predict the same nonlinear variation of rolling moment with roll angle that appeared in the experiment. This nonlinearity includes regions of local static roll instability, which is attributed to vortex breakdown.
Nosocomial infections surveillance.

Nosocomial infections are a major worldwide public health problem. In some countries the true magnitude of the problem may not be recognized. Nevertheless, when susceptible hospitalized individuals have contact with microbes, some will develop infections. It may be difficult for a country's health authorities to be sensitive to this situation due to the enormity of other health and social problems. But there is increasing recognition of the impact nosocomial infections have on the healthcare system, and there is increasing interest in initiating institutional infection control programs. Healthcare professionals are dedicated to do the patients no harm and, in this instance, to reduce the occurrence of nosocomial infections to the lowest possible level. Initial attempts at control and prevention included the incorporation of generic measures into patient care routines with varying degrees of success. However, the increasing demands on the scarce healthcare resources available made it necessary to be more efficient and direct in control and prevention actions. In order to improve our efforts, we recognized the usefulness and necessity to incorporate disease surveillance into our routine patient care activities. The importance of surveillance in reducing the incidence of nosocomial infections is well documented in the literature.1-3 The Institute of Medicine, in a recent report,4 called for increasing the collection of nosocomial infection surveillance data in order to increase our knowledge of nosocomial infections. In our initial surveillance enthusiasm, we incorporated comprehensive or total surveillance throughout the hospital. However, the realities of life came dramatically (and at times traumatically) into the picture and the "bandwagon" of surveillance was appropriately challenged.5 Surveillance may be defined as the continued collection of data appropriate to defining the problem, collation and analysis of these data, and preparation and distribution of a summary report to those with an interest in and/or a need to be informed about the problem. A logical endpoint to surveillance is formulating control and prevention measures from interpretation of the analyzed data. Without a specific action, surveillance is purely archival; that is, the data increases use of shelf space, but does not decrease the occurrence of disease.6
A proximity-based approach to assessing habitat

Planning for either a single species, multiple species, or ecosystems is greatly dependent on spatial interactions in the landscape. Problems exist for evaluating wildlife habitat changes over large ranges of space and time. This paper illustrates the use of Geographic Information Systems (GIS) to evaluate habitat for a single species, ruffed grouse (Bonasa umbellus), following a time series of forest harvests. A habitat suitability model for ruffed grouse is utilized on a two-township study area in north-central Minnesota to assess the habitat suitability changes over time using an even-aged area-control harvesting plan. The results are presented as a habitat quality change map and a contingency table, representing the movement of habitat class areas between time periods resulting from the proposed harvesting. We developed a neighborhood definition to allow for spatially varying habitat values. This work illustrates the ability to ‘look ahead’ and ‘around’ in estimating the impact on wildlife habitat resulting from alternative future management activities.
Molecular modeling of polyamidoamine (PAMAM) Starburst™ dendrimers

Abstract Highly organized polymeric structures known as Starburst™ dendrimers have been subjected to qualitative structural evaluation using molecular modeling tools. These molecules are becoming increasingly important in several different fields ranging from drug delivery to applications in selective adsorption and catalysis, and even as chromatographic materials and adsorbents. Our studies suggest that low generation dendrimers are somewhat asymmetric and that the modification of the dendrimers with molecules such as porphyrins, may lead to the reduced accessibility of other surface groups thus limiting further modification.
Cryptantha schoolcraftii (Boraginaceae), a new species of section Oreocarya from Nevada

A new species,Cryptantha schoolcraftii, is described and illustrated. It is related to theC. nubigena-sobolifera alliance but differs in short duration and lowland habitat. It further differs fromC. sobolifera in having smaller corollas, shorter nutlets, and a shorter style.
Comparison of the Two Formulations of w-u-v and w-F in Nonlinear Plate Analysis

In a moderately large deflection plate theory of von Karman and Chu-Herrmann, one may consider thin-plate equations of either the transverse and in-plane displacements, w-u-v formulation, or the transverse displacement and Airy function, w-F formulation. Under the Galerkin procedure, we examine if the modal equations of two plate formulations preserve the Hamiltonian property which demands energy conservation in the conservative limit of no damping and forcing. In the w-F formulation, we have shown that modal equations are Hamiltonian for the first four symmetric modes of a simply-supported plate. In contrast, the corresponding modal equations of w-u-v formulation do not exhibit the Hamiltonian property when a finite number of sine terms are included in the in-plane displacement expansions. ©2002 ASME
Activation of the progesterone signaling pathway by methyl-β-cyclodextrin or steroid in Xenopus laevis oocytes involves release of 45-kDa Gαs

Abstract Treatment of Xenopus laevis oocytes with cholesterol-depleting methyl-β-cyclodextrin (MeβCD) stimulates phosphorylation of mitogen-activated protein kinase (MAPK) and oocyte maturation, as reported previously [Sadler, S.E., Jacobs, N.D., 2004. Stimulation of Xenopus laevis oocyte maturation by methyl-β-cyclodextrin. Biol. Reprod. 70, 1685–1692.]. Here we report that treatment of oocytes with MeβCD increased levels of immunodetectable 39-kDa mos protein. The protein synthesis inhibitor, cycloheximide, blocked the appearance of Mos, blocked MeβCD-stimulated phosphorylation of MAPK, and inhibited MeβCD-induced oocyte maturation. These observations suggest that MeβCD activates the progesterone-signaling pathway. Chemical inhibition of steroid synthesis and mechanical removal of follicle cells were used to verify that MeβCD acts at the level of the oocyte and does not require production of steroid by surrounding follicle cells. Cortical Gαs is contained in low-density membrane; and treatment of oocytes with progesterone or MeβCD reduced immunodetectable levels of Gαs protein in cortices and increased internal levels of 45-kDa Gαs in cortical-free extracts. Dose-dependent increases in internal Gαs after treatment of oocytes with progesterone correlated with the steroid-induced maturation response, and the increase in internal Gαs after hormone treatment was comparable to the decrease in cortical Gαs. These results are consistent with a model in which release of Gαs from the plasma membrane is involved in activation of the progesterone-signaling pathway that leads to amphibian oocyte maturation.
Monitoring for Fruit Damage in Processing Tomatoes: Use of a Dynamic Sequential Sampling Plan'

The cost-reliability of two binomial sampling procedures for monitoring tomato fruitworm (TFW), Heliothis zea (Boddie), and beet armyworm (BAW), Spodoptera exigua (Hubner), fruit damage in processing tomatoes are compared. The random procedure which entails sampling 30 fruit at each of several sites in a field when compared with sampling all fruit on single plants at several sites overestimated TFW and BAW damage by 62% but proved more cost reliable when corrected for the bias. A dynamic threshold is developed taking into account the earliness or lateness of the crop and the associated likeliness of increased damage later in the season. A binomial sequential sampling program which utilizes these thresholds is presented which allows for the fruit damage status to be rapidly and reliably estimated.
Thixotropic behavior of gel‐like systems

The changes of shear stress with time under constant shear rate and temperature of several pigmented acrylic polymer gels were examined. This behavior, known as thixotropy, was interpreted based on a model which separates the stress into two regions. Region I covers the growth of the stress up to the yield point, represented by a peak stress, F0. Region II covers the decay of the stress from the peak to the point it attains an asymptotic value, F∞. The material in region I is assumed to be elastic and in region II is represented by a dynamic equilibrium between structure A, which is non-Newtonian and structure B, which is Newtonian. The transitions between A and B represent structure degradation and structure recovery. The concentrations of A and B are solved explicitly. The total shear stress is then evaluated following a theory proposed by Ree and Eyring and is shown to give relationship between shear stress–shear rate–shearing time in good qualitative agreement with experimental observations. The ratio (F0 − F∞)/F∞, defined as the coefficient of thixotropy, is sensitive to the fundamental physical chemical parameters of the system and is easy to measure. It is shown to be useful in the characterization of thixotropic materials such as gels. Methods for evaluating the elastic modulus and yield stress of the material in the gel state are also illustrated.
Thoracic aorta prostacyclin production is not altered during early atherosclerosis development in young swine

Decreased prostacyclin synthesis by atherosclerotic vascular tissue has been demonstrated in both adult animal models and man. The purpose of this study was to determine whether the decrease in prostacyclin synthesis by the vessel wall was evident during the initial stages of atherosclerosis development and thus a potential contributor to atherogenesis. Thirty-two Yucatan miniature swine entered the study at 3 months of age and were placed on either an atherogenic or regular diet for 10, 30, 90, or 180 days. At that time, the thoracic and abdominal aorta were harvested. Pairs of discs were punched out of the distal thoracic aorta and placed in Krebs Henseleit HEPES buffer. The buffer was then exchanged for either fresh buffer or stimulated with calcium ionophore A23187 (10 −4 m ). Aliquots were collected at 10 min for analysis of prostacyclin production by radioimmunoassay of its stable metabolite 6-keto-prostaglandin F 1α . Thoracic aorta sections were prepared for atherosclerosis assessment by light microscopy, and the abdominal aorta was stained with Sudan IV. No significant differences were noted between the diet groups at 10 and 30 days. After 90 days, a significant difference was noted ( P P > 0.05) were noted between the diet groups with regard to the basal and stimulated rates of prostacyclin production. Our findings showed that prostacyclin synthesis was not altered during the initial development or early progression of aortic atherosclerosis induced by hypercholesterolemia.
Beardedness as a Stimulus Variable: Note on Methodology and Meta-Analysis of Impression-Formation Data:

Apparently contradictory results have been obtained in studies of beardedness as a factor affecting impressions of men's personalities. Addison's (1989) attempt to account for this incongruence has focused on cognitive-developmental characteristics of subjects tested in relevant studies. An alternative to Addison's explanation, based on methodological considerations other than sampling, is suggested here. Broader implications of research on beardedness for conceptual meta-analysis in the social psychology of impression-formation are also discussed.
Inherited defect in hereditary pancreatitis.

Definite inherited defect in hereditary pancreatitis (HP) is not known. A new kindred with 3 definite and 6 suspected cases of HP was investigated for possible inherited abnormalities. No aminoaciduria (except for a slight rise in urinary histidine in one patient) and no hyperparathyroidism, hyperlipidemia, or chromosomal abnormality was present. An increase in serum IgM level of a polyclonal type was noted in 3 definitely affected sisters and also in 2 nonaffected members. Serum alpha-l-antitrypsin and serum trypsin inhibition were normal. However, very marked dilatation and ectasia of the pancreatic duct were found in the propositus. Reviewing the data from this family and previously described kindreds, it is postulated that the genetic abnormality in HP encompasses a wide variety of structural and anatomical defects in the sphincter of Oddi or the pancreatic ductal system. These predispose to intermittent obstruction of the duct with concomitant activation of enzymes and ductal metaplasia. In suspected cases an early effort should be made to outline the pancreatic duct as the defect may be amenable to surgery.
Reimplantation of a glenoid component following component removal and allogenic bone-grafting.

Background: Glenoid component loosening has been a leading cause of failure of total shoulder arthroplasty. In the present study, we evaluated the outcome of reimplantation of a new glenoid component following removal of the previous glenoid component and placement of an allograft in order to determine the results, risk factors for an unsatisfactory outcome, and rate of failure associated with this procedure. Methods: We reviewed the data on seven shoulders in seven patients. At the time of glenoid component reimplantation, two shoulders received a cemented all-polyethylene glenoid component, three received a bone-ingrowth metal-backed component with columns and screws, and two received a bone-ingrowth metal-backed component with columns and screws augmented with bone cement. The average duration of follow-up was seventy-nine months. At the time of the latest follow-up, all patients were evaluated clinically and radiographically, patient satisfaction was assessed, and the result was graded according to a modified Neer rating system. Results: Two patients had positive growth of Propionibacterium acnes on culture of intraoperative specimens obtained at the time of revision surgery and had continuing pain, and both underwent repeat revision. The remaining five patients expressed satisfaction with the procedure and stated that they felt better following surgery. The mean preoperative pain score for these five patients (on a scale from 1 to 5) was 4.6, and the mean postoperative pain score was 2.4 (p = 0.0042). Range of motion, however, did not improve. The Neer rating of the result (determined for the five patients who did not undergo repeat revision) was excellent for one patient, satisfactory for one, and unsatisfactory (because of limitation of motion) for three. Conclusions: Reimplantation of a glenoid component into a previously grafted bed can provide pain relief for most patients, but motion cannot be reliably improved. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.
The HVEM-Tandem Accelerator Facility at Argonne National Laboratory

Abstract The HVEM-Tandem National User Facility consists of a modified Kratos/AE1 EM7 HVEM with a maximum accelerating voltage of 1.2 MeV, interfaced to both a 2MV National Electrostatics tandem ion accelerator and a 300 kV Texas Nuclear ion accelerator. The latter is being replaced with a 650 kV National Electrostatics accelerator which should be fully operational in FY 1987. These accelerators provide a wide range of ion species with energies from 25 keV to 8 MeV. The combination of HVEM and ion accelerators provides a truly unique capability for ion irradiation/implantation experimentation along with simultaneous microscopy. The HVEM-Tandem Facility currently is employed for a wide range of materials research, including basic in situ studies of mechanical properties, oxidation and hydrogen effects in metals, radiation effects including ion and electron irradiation-induced phase changes and general defect analysis. More than half of these studies are conducted by non-ANL scientists from universities and other national laboratories. Access to the National User Facility is by means of research proposals which are reviewed by a Steering Committee composed of both Argonne and non-Argonne scientists representing the user community.
Effect of high-energy limits on the nucleon form factors

The consequences of using the high-energy conditions recently proposed bySachs, on the usual dispersion-theoretic fit to the electromagnetic form factors of the nucleon, are examined. Thus it is shown that as a consequence of these conditions and the usual conditions that define the charge and the anomalous magnetic moments, one needsat least four pion-pion resonances with spin and parity 1−, two of which are iso-vector and two of which are iso-scalar. If the masses of these resonances are known, the Pauli form factors of both the proton and the neutron are determined in terms of these masses. Then there are only two free parameters to fit the Dirac form factors. Numerical results are discussed in terms of presently known pion-pion resonances.
Handling benefits of steering a third axle

This work examines the steady state handling effect of steering the rear axle of a three-axle vehicle in terms of the equivalent wheelbase and understeer. These quantities are derived from steady state conditions of a three-axle vehicle model which is analogous to the two-axle model. It is found that a very simple rear-axle steer control strategy improves both the equivalent wheelbase and the understeer. The expected improvement is larger on low-friction surfaces. The equivalent wheelbase of the rear-axle-steered vehicle calculated from the steady state condition of the dynamic equations of motion equals the intuitively expected kinematic result and was demonstrated on a test vehicle, validating the three-axle steady state handling model's ability to predict the rear-axle-steering performance. Language: en
Lack of Activity of Sulfamethoxazole and Trimethoprim Against Anaerobic Bacteria

The activity of sulfamethoxazole (SMX), trimethoprim (TMP), and the combination of the two was determined against a variety of anaerobic bacteria. Brucella agar was somewhat inhibitory for SMX and TMP but activity was good and equivalent in Diagnostic Sensitivity Test Agar (Oxoid) and Mueller-Hinton agar and the latter was selected for use in these studies. Agar dilution susceptibility tests showed that 95 of 98 anaerobic isolates were resistant to >/=100 mug of SMX per ml and 85 were resistant to >/=6.25 mug of TMP per ml. "Checkerboard" agar dilution studies of combined activity showed that 66 of 72 isolates were resistant to >/= (100 mug of SMX per ml + 6.25 mug of TMP per ml) and only six isolates were susceptible to the synergistic activity of the combination. The majority of 32 isolates tested by the disk diffusion method were also resistant to SMX and TMP individually and to the combination 25-mug disk. Correlation between agar dilution minimal inhibitory concentration and disk zone size results was in general good for individual agents. Four Bacteroides fragilis isolates were inhibited by the combination 25-mug disk but were resistant to SMX + TMP by agar dilution "checkerboard." This discrepancy may have been due to different incubation periods since disk results also showed resistance when read after 48 h (as is done with agar dilution) rather than the standard 24 h for disk tests. These studies suggest that SMX and TMP, either individually or in combination, are not active against the great majority of anaerobic bacteria.
Thermodynamic Analysis and Growth Characterization of thick GaN films grown by Chloride VPE using GaCl3/N2 and NH3/N2

Thermodynamic calculations were carried out on chloride transport vapor phase epitaxy of GaN using GaCl3/N2 and NH3/N2. At typical growth temperature and gas flow rates, both GaN formation and gas phase etching reactions of GaN are thermodynamically favored. Under thermodynamic equilibrium, most ammonia should decompose to nitrogen and hydrogen gases and gas phase etching of GaN occurs by HCl. From experimental measurements, less than 10% of the incoming ammonia decomposes and under this condition, GaN formation from GaCl3/N2 and NH3/N2 is thermodynamically favored. Higher V/III ratios give a larger driving force for GaN fromation. These calculations match our experimental results. Experimentally, we have optimized the growth conditions of GaN. High crystalline quality thick GaN films (10 ~ l5µm) were grown on c-Al2O3. The GaN films show band edge emission dominated PL at both room temperature and 77 K. Only one set of diffraction peaks from % MathType!MTEF!2!1!+- % feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqr1ngB % PrgifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaqFr0x % c9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8fr % Fve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaadaqada % qaaiaaigdacaaIWaGabGymayaaraGaaGOmaaGaayjkaiaawMcaaaaa % !3C38! $$\left( {10\bar 12} \right)$$ planes with 60° spacing in the ϕ-scan of X-ray diffraction are observed. This indicates that the GaN films grown on c-Al2O3 are single crystalline. Typical growth rates were about 10 ~ l5µm/hr and typical Hall mobility values of GaN films were in the range of 3 to 40 cm2/Vsec.
Frictional behaviour of non-Newtonian lubricants

Abstract This investigation is concerned with the prediction of the frictional behavior of non-Newtonian fluids in a statically loaded journal bearing. The pressure distribution, friction and bearing load capacity are obtained for various values of the flow behaviour index, n. For the pseudoplastic fluids (n 1) exhibited increases in the friction forces and load. The coefficient of friction was found to decrease as the value of n is increased, provided the dimensionless load exceeded a certain value
A hierarchical Bayesian model to estimate and forecast ozone through space and time

A Bayesian hierarchical regime switching model describing the spatial–temporal behavior of ozone (O3) within a domain covering Lake Michigan during spring–summer 1999 is developed. The model incorporates linkages between ozone and meteorology. It is specifically formulated to identify meteorological regimes conducive of high ozone levels and allow ozone behavior during these periods to be different from typical ozone behavior. The model is used to estimate or forecast spatial fields of O3 conditional on observed (or forecasted) meteorology including temperature, humidity, pressure, and wind speed and direction. The model is successful at forecasting the onset of periods of high ozone levels, but more work is needed to also accurately identify departures from these periods.
The tip of the tail needle affects the rate of DNA delivery by bacteriophage P22.

The P22-like bacteriophages have short tails. Their virions bind to their polysaccharide receptors through six trimeric tailspike proteins that surround the tail tip. These short tails also have a trimeric needle protein that extends beyond the tailspikes from the center of the tail tip, in a position that suggests that it should make first contact with the host’s outer membrane during the infection process. The base of the needle serves as a plug that keeps the DNA in the virion, but role of the needle during adsorption and DNA injection is not well understood. Among the P22-like phages are needle types with two completely different C-terminal distal tip domains. In the phage Sf6-type needle, unlike the other P22-type needle, the distal tip folds into a ‘‘knob’’ with a TNF-like fold, similar to the fiber knobs of bacteriophage PRD1 and Adenovirus. The phage HS1 knob is very similar to that of Sf6, and we report here its crystal structure which, like the Sf6 knob, contains three bound L-glutamate molecules. A chimeric P22 phage with a tail needle that contains the HS1 terminal knob efficiently infects the P22 host, Salmonella enterica, suggesting the knob does not confer host specificity. Likewise, mutations that should abrogate the binding of L-glutamate to the needle do not appear to affect virion function, but several different other genetic changes to the tip of the needle slow down potassium release from the host during infection. These findings suggest that the needle plays a role in phage P22 DNA delivery by controlling the kinetics of DNA ejection into the host.
Fragmentation of marine snow by swimming macrozooplankton: A new process impacting carbon cycling in the sea

Abstract Comparisons of the abundances and size distributions of marine snow (aggregated particles >0.5 mm in diameter) in the upper 100 m of the water column at ten stations off Southern California in the late afternoon with those in the same parcel of water the following morning, after nocturnal vertical migration by zooplankton had occurred, revealed the existence of a previously undescribed process affecting marine particle dynamics. Aggregate abundances increased overnight and changes were positively and significantly correlated only with the abundance of the common euphausiid, Euphausia pacifica , and with no other biological or physical factor. Moreover, mean aggregate size decreased and aggregate size distributions shifted toward smaller size classes when euphausiids were abundant. The only conclusion consistent with these findings was that euphausiids were physically disaggregating marine snow into smaller, more numerous aggregates through shear stresses generated while swimming. Video-recording of both tethered and free-swimming E. pacifica in the laboratory dramatically confirmed that aggregates passing within 8–10 mm of the animal's abdomen were fragmented either by entrainment and direct impact with the beating pleopods or by eddies generated during swimming. At the abundances observed in this study, swimming E. pacifica would have sufficiently disturbed 3–33% of the water column each night to disrupt the aggregates contained therein. This is the first evidence for the fragmentation of large particles by the swimming activities of zooplankton and suggests that macrozooplankton and micronekton play a significant role in the particle dynamics of the water column regardless of whether they consume particles or not. Disaggregation of marine snow by swimming and migrating animals may alter the sizes of particles available to grazers and microbial colonizers and reduce the flux of particulate carbon by generating smaller particles, which potentially sink more slowly and reside longer in the water column. This newly discovered process reduces carbon flux while simultaneously conserving carbon and provides a previously unconsidered link between animal behavior and the biogeochemistry of the sea. It may help explain the exponential reduction in particle flux with depth observed in parts of the ocean and help balance oceanic carbon models.
Perceiving molecular themes in the structures and bonding of intermetallic phases: the role of Hückel theory in an ab initio era.

Qualitative molecular orbital theory is central to our understanding of the bonding and reactivity of molecules and materials across chemistry. Advances in computational technology and methodology, however, have made ab initio or density functional theory calculations a simpler alternative, offering reliable results on increasingly large systems in a reasonable time-scale without the need for concerns about the approximations and parameterization of semi-empirical one-electron based methods. In this perspective, we illustrate how the availability of higher-level computational results can augment, rather than supplant, the insights provided by approaches such as the simple and extended Huckel methods. We begin by describing a way to parameterize Huckel-type Hamiltonians against DFT results for intermetallic systems. The potential for chemical understanding embodied by such orbital-based models is then demonstrated with two schemes of bonding analysis that originated in them (but can be extended to DFT results): the μ3-acid/base model and the μ2-Huckel chemical pressure analysis, which translate the molecular concepts of acidity and electronic/steric competition, respectively, into the context of intermetallic chemistry.
Retrovirally Expressed Metal Response Element-Binding Transcription Factor-1 Normalizes Metallothionein-1 Gene Expression and Protects Cells against Zinc, but Not Cadmium, Toxicity

Abstract Metal response element (MRE) transcription factor-1 (MTF1), a member of the Cys 2 -His 2 class of zinc-finger transcription factors, is best known for its robust transcriptional regulation of mammalian metallothionein ( MT ) genes. MTF1 is also believed to play a generalized role in regulating genes involved in protection against heavy metals and oxidative stress. MTF1 binding to MRE motifs is regulated by changes in intracellular zinc (Zn 2+ ) concentration. Molecular dissection of MTF1 has been hindered by its high constitutive trans - activity following transient transfection and the failure of these systems to examine genes packaged in native chromatin. In developing a system to avoid these problems, we employed a high-efficiency retroviral transduction system to reintroduce MTF1 into mouse Mtf1(−/−) knockout cells (dko7). Electrophoretic mobility shift assays demonstrated that MTF1 retrovirally transduced dko7 cells (MTF1dko7) possess levels of inducible MTF1–MRE binding activity similar to that seen in mouse hepatoma Hepa-1 cells, and MTF1 binding could be modulated over a 20-fold range by varying the concentration of Zn 2+ present in the culture medium. The dko7 cells exhibited no change in Mt1 gene expression upon Zn 2+ or cadmium (Cd 2+ ) treatment; in contrast, in MTF1dko7 cells, Zn 2+ or Cd 2+ induced MT1 mRNA accumulation in a dose-dependent manner. Interestingly, MTF1dko7 cells showed resistance to Zn 2+ toxicity, but negligible resistance to Cd 2+ . Concomitantly, MT1 protein levels in MTF1dko7 cells were inducible to the same degree as that in Hepa-1 cells when treated with Zn 2+ , but not with Cd 2+ . Together, our studies suggest that MTF1-mediated regulation of gene expression is sufficient to protect cells against Zn 2+ toxicity and may be necessary but not sufficient to protect cells against Cd 2+ toxicity.
Plasma immersion ion implantation of polymers and silver-polymer nano composites

Abstract Biocompatibility and wear resistance are the outstanding properties of hydrogenated diamond like carbon (a-C:H), making it a very suitable material for medical applications, especially as a coating for joint replacing implants. Recently the demand for additional antimicrobial features of such coatings is becoming more and more pronounced. One possibility is the introduction of silver particles, which has already been done for a variety of polymer based products. We have developed a hybrid synthesis method to produce silver nano particle containing a-C:H based on the ion induced transformation of silver–polymer nano composites into Ag containing a-C:H. Now those results have been transferred to plasma immersion ion implantation (PIII), which allows a 3D treatment and thus is the next step towards industrial application. PIII experiments have been conducted with a mixture of CH4 and Ne as well as Ar with a pulsed bias of 40 kV. From beam line ion implantation experiments, the correlation of fluence and ion energy with film properties is well known, so this work is focused on the investigation of plasma etching and sputtering effects, caused by direct exposure to the plasma. It will be shown, that these effects can be compensated by adding hydrocarbon species to the plasma. Using this method, film properties like density, hydrogen content and sp3 fraction comparable to those of typical a-C:H can be achieved. RBS, ERD and Raman spectroscopy are used to investigate and to understand the densification process.
Spin-moment formation and reduced orbital polarization in LaNiO 3 /LaAlO 3 superlattice: LDA+U study

Density functional band calculations have been performed to study LaNiO${}_{3}$/LaAlO${}_{3}$ superlattices. Motivated by recent experiments reporting the magnetic and metal-insulator phase transition as a function of LaNiO${}_{3}$ layer thickness, we examined the electronic structure, magnetic properties, and orbital occupation depending on the number of LaNiO${}_{3}$ layers. Calculations show that the magnetic phase is stabler than the nonmagnetic for finite and positive $U$ values. The orbital polarization is significantly reduced by $U$ even in the magnetic regions. The implications of the results are discussed in comparison to recent experimental and theoretical studies within the limitations of the $\mathrm{LDA}+U$ method.