cssi/SciSciGPT-SciSciNet huggingface dataset:
The importance of universal psychological needs for understanding motivation in the workplace

A key proposition of self-determination theory (SDT) is that human beings have deeply evolved psychological needs to be competent, autonomous, and related to others. In contexts where these needs are satisfied, people evidence more volitional, high-quality motivation and greater well-being. Conversely, when these needs are thwarted, people display diminished motivation and more symptoms of ill-being. This article addresses how the SDT concept of basic psychological needs differs from needs concepts in other psychological and management theories; provides empirical evidence for the validity of our approach; relates need satisfaction to autonomous motivation (i.e., intrinsic motivation and fully internalized extrinsic motivation) and controlled motivation (i.e., external and introjected forms of extrinsic motivation); explains how need satisfaction versus thwarting affects engagement and effective performance; examines how social environments, personality characteristics, and people’s long-term goals affect satisfaction versus thwarting of their basic psychological needs; and then discusses the relevance of these issues for management.
Quality Assessment of Community Service Activities

Abstract Community service generally is not valued highly or rewarded by university administrators and peers. Social work faculty tend to perform activities which reflect a wide range of quality and value to the recipient. The authors surveyed graduate social work deans and requested that they evaluate an extensive list of commonly-reported community service activities. The authors then constructed a rank ordering. Findings indicate that activities which are most valued tend to employ professional expertise, are unpaid, are offered to professionals or agencies, reflect a sizable time commitment, and provide visibility for the school.
Stability of DX centers in AlxGa1-xAs alloys.

On determine la dependance de l'energie de liaison de ces centres DX vis-a-vis de la bande interdite. Examen des modifications de la structure de bandes resultant des changements dans la composition des alliages et dans la pression hydrostatique
Evaluation of early-visual processing techniques for automatic object recognition

We use a modular object recognition system as a platform to evaluate the performance of various image processing techniques. The recognition system consists of modules for image restoration, detection, segmentation, feature extraction, invariant mapping, and classification. We are developing the system to classify objects in laser radar range imagery. The stages of the system preceding the classification stage are collectively referred to as preprocessing or early-visual processing because of the analogy with biological vision. In previous work, we presented results on invariant mapping techniques and concluded that the bi-directional log- polar mapping (BLP) method gave the best performance when evaluated within the context of an object recognition system. In the present study, we employ the BLP invariance module and use similar criteria for evaluation of several candidate image restoration and feature extraction modules. We use synthetic laser radar images of four vehicles rotated to various orientations in the field of view, scaled to various ranges, and corrupted by increasing levels of sensor noise for this evaluation. This study indicates that Markov-Random-Field image restoration and features extraction based on graded edges are a combination that provides the best recognition performance, as well as robustness to noise and discretization.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Optical Emission Measurements of Laser Initiated, RF Sustained High Pressure Seeded Plasmas

Summary form only given. High density ~1012-1014 cm-3, large (500-2500 cc) volume, high-pressure air and air constituent atmospheric (50-760 torr) plasmas are of great interest in variety of scientific and industrial applications such as material processing, biological decontamination, radar and stealth antennas. We present a technique for producing these plasmas and measuring their temperature, density and recombination rates by means of optical emission and millimeter wave interferometry. The plasma is produced by utilizing a seed (15 mtorr) organic gas, tetrakis (dimethyl-amino) ethylene (TMAE), in high-pressure air and air component gases is pre-ionized by a 393 nm excimer laser (300 mJ), 20 ns pulse width. The seed plasma is then sustained by the efficient absorption of the pulsed 13.56 MHz radio frequency (RF) power (1-25 kW) through inductive coupling of the wave fields, which reduces the RF power requirement for plasma initiation to a great extent. High-resolution optical emission spectroscopic (OES) diagnostics are carried out to measure the density and temperature profiles of the plasma. We use a 0.5-m monochromator with a 1200-groove/mm grating with entrance and exit slits of 10 mum to obtain high resolution. The monochromator is calibrated for spectral intensities between 200-800 nm with a Hg-Ar light source. Hbeta (486.132 nm) and Halpha (656.28 nm) line broadening techniques have been used to measure the FWHM, which in turn used to measure the density and temperature of the plasma. A small amount of H2 (2% mole fraction) is mixed with the working gas. The background emission spectrum, due to the N2 first positive system B3Pig-A3Sigmau + is also measured by turning off hydrogen flow. For the temperature (0.4-0.6 eV) and density (1012-1014 cm -3) range of the plasma generated, the line width is dominated by Stark broadening. The spectroscopic measurements are used to obtain density and collisional rates are compared with those using a 105 GHz interferometer. The spectroscopic measurements can also provide highly localized measurements of the plasma conditions in regions that are less accessible to interferometer measurements
High dose per fraction dosimetry of small fields with gafchromic EBT2 film.

Purpose: Small field dosimetry is prone to uncertainties due to the lack of electronic equilibrium and the use of the correct detector size relative to the field sizemeasured. It also exhibits higher sensitivity to setup errors as well as large variation in output with field size and shape. Radiochromic film is an attractive method for reference dosimetry in small fields due to its ability to provide 2D dosemeasurements while having minimal impact on the dose distribution. Gafchromic EBT2 has a dose range of up to 40 Gy; therefore, it could potentially be useful for high dose reference dosimetry with high spatial resolution. This is a requirement in stereotactic radiosurgery deliveries, which deliver high doses per fraction to small targets. Methods: Targets of 4 mm and 12 mm diameters were treated to a minimum peripheral dose of 21 Gy prescribed to 80% of the maximum dose in one fraction. Target doses were measured with EBT2 film (both targets) and an ion chamber (12 mm target only). Measureddoses were compared with planned dose distributions using profiles through the target and minimum peripheral dose coverage. Results: The measured target doses and isodose coverage agreed with the planned dose within ±1 standard deviation of three measurements, which were 2.13% and 2.5% for the 4 mm and 12 mm targets, respectively. Conclusions: EBT2 film is a feasible dosimeter for high dose per fraction reference 2D dosimetry.
Linear growth characteristics of children with cleft lip and palate

Objective: To study the linear growth characteristics of children with isolated cleft lip (CL), cleft palate (CP), or both (CLP) and to determine whether this population is at risk for short stature. Study design: Retrospective chart review identified 324 patients with CL, CP, or CLP that displayed no additional congenital anomalies. Longitudinal height and growth rate analyses were performed on routine anthropometric measurements gathered from hospital and clinic records. One-sample t tests ( p < 0.05) of average height percentiles were performed at yearly intervals. Analysis of variance was performed on clefting subgroups. Results: From birth to 10 years of age, the average height of both male and female white patients is consistently near the 40th percentile. At yearly intervals, 60% of male and 70% of female average heights demonstrate statistical difference from the population mean. For all patients, 64% of male but only 36% of female growth rates, from 2.5 to 12 years of age, were above the population mean. Conclusions: White children from birth to 10 years of age with isolated CL, CP, or CLP demonstrated a mean height below the population mean. These data suggest that children with isolated clefting manifest an intrinsic tendency toward short stature. In addition, male patients display above-average growth rates, whereas female patients display below-average growth rates, from 2 to 18 years of age. The data imply that female patients may be at increased risk of overall short stature, whereas male patients may eventually obtain mean population height. (J Pediatr 1997;131:707-11)
Dissociation of ribosomes on polypeptide chain termination and origin of single ribosomes.

After polypeptide chain termination, ribosomes are released from polysomes in the form of ribosomal subunits. Single ribosomes, which differ from ribosomes found in polysomes, are formed by association of the released subunits.
736 EFFECT OF EXTRACELLULAR COPPER (Cu) ON METALLOTHIONEIN METABOLISM IN NORMAL AND MENKES FIBROBLASTS

Previously, we demonstrated that the abnormal accumulation of Cu in Menkes disease (MD) fibroblasts (Fb) is associated with an increased amount of metallothionein (MT) (2-3 times normal) (Pediat. Res., in press). To define the basic defect in MD, we investigated the effect of varying concentrations of extracellular Cu (exCu) on the regulation of CuMT metabolism informal (N) and MD Fb. Relative levels of MT were measured by 35S-cysteine incorporation into the 10,000 MW Cu-binding cytosolic protein. Total intracellular Cu was measured by atomic absorption spectrometry. After exposure of N and MD Fb to 2 ug/ml Cu (as CuCl2) maximal levels of MT synthesis were attained within 8 h and remained elevated for at least 56 h. Additional Cu (up to 20 ug/ml) did not increase the rate of MT synthesis above that observed with 2 ug/ml. Pulse-chase experiments demonstrated no difference in the half-life (T1/2=48-60 h) of MTs in N or MD Fb in the presence or absence of exCu. These results demonstrated that MT was an inducible protein in both N and MD Fb. Also, the rate of degradation of the MTs was the same in both the N and MD Fb. Although the mechanism of MT induction by exCu appears normal in MD Fb, the suppression of MT synthesis in the absence of excess Cu may be defective. This regulatory defect results in abnormally high constitutive levels of MT in MD Fb. Whether this defect in regulation of MT synthesis is transcriptional or translational is currently under investigation.
Constraints on new chiral fermions in the standard model.

In the light of the new experimental data on standard-model parameters, we investigate the implications of new types of chiral fermions with masses above present experimental detection capabilities. We show that new chiral fermions may exist, but only under very special circumstances; one is {ital R}-parity-violating supersymmetry. The analysis is based on the present bounds on the number of light neutrals and on the lack of flavor-changing neutral currents. No such limits exist for vectorlike fermions of the type anticipated in supersymmetric and in some grand unified extensions.
Binding of antidepressants to human brain receptors: focus on newer generation compounds

Using radioligand binding assays and postmortem normal human brain tissue, we obtained equilibrium dissociation constants (Kds) for 17 antidepressants and two of their metabolites at histamine H1, muscarinic, α1-adrenergic, α2-adrenergic, dopamine D2, serotonin 5-HT1A, and serotonin 5-HT2 receptors. Several newer antidepressants were compared with older drugs. In addition, we studied some antimuscarinic, antiparkinson, antihistamine, and neuroleptic compounds at some of these receptors. For the antidepressants, classical tricyclic antidepressants were the most potent drugs at five of the seven receptors (all but α2-adrenergic and 5-HT1A receptors). The chlorophenylpiperazine derivative antidepressants (etoperidone, nefazodone, trazodone) were the most potent antidepressants at α2-adrenergic and 5-HT1A receptors. Of ten antihistamines tested, none was more potent than doxepin at histamine H1 receptors. At muscarinic receptors antidepressants and antihistamines had a range of potencies, which were mostly weaker than those for antimuscarinics. From the in vitro data, we expect adinazolam, bupropion, fluoxetine, sertraline, tomoxetine, and venlafaxine not to block any of these five receptors in vivo. An antidepressant's potency for blocking a specific receptor is predictive of certain side effects and drug-drug interactions. These studies can provide guidelines for the clinician in the choice of antidepressant.
Some consequences of the inequality conditions in contact and crack problems

The importance of the inequalities and related side conditions that must be incorporated in contact and crack problems is emphasized and the ensuing consequences explored. An asymptotic analysis of the transitions from slip to separation, stick to slip, and stick to separation is carried out. The inequalities in contact problems make the contact pressure continuous for all levels of friction. They also make a direct transition from stick to separation impossible, unless the combination of materials is special. The inequalities in crack problems are less stringent, but they preclude certain singularities that appear to have flourished in the literature previously.
Advances in Respiratory Care

Patients who have pulmonary conditions are comhow best to recruit the noncompliant ARDS lung and mon in critical care. The therapies and technologies used to assure safe passage throughout hospitalization and beyond are changing constantly as we learn and apply the scientific evidence. In this issue of Critical Care Nursing Clinics of North America, topics cover some of the most challenging pulmonary conditions. The articles are designed to serve as an update for the reader and an accurate reference for clinical practice. ‘‘Waiting to exhale’’ is a phrase synonymous with obstructive diseases, such as acute asthma, chronic obstructive pulmonary disease (COPD), and obstructive sleep apnea (OSA). Winters and Hockman cover asthma and COPD, respectively, and Ecklund and Kurlak address the complexity of caring for the bariatric patient who has OSA. All three of these conditions are increasing in prevalence and severity. Associated outcomes continue to be poor, making it essential that available evidence is used to plan care appropriately. With the authors’ help, we indeed may help these patients exhale. Although our understanding of acute respiratory distress syndrome (ARDS) continues to grow, there are many unanswered questions about how best to ventilate patients afflicted with the condition. A recent randomized controlled study conducted by the National Institutes of Health ARDS Network demonstrated that lower tidal volumes (6 mL/kg) are more lung protective than traditional volumes (12 mL/kg) [1]. Questions continue to remain, however, about
Effects of Multi-Channel Consumers' Perceived Retail Attributes on Purchase Intentions of Clothing Products

Abstract Consumers are increasingly shopping through multiple channels, providing opportunities to retailers who can increase profits by crossselling products through multi-channels. The objective of the study was to examine the effects of multi-channel consumers' perceived retail attributes on purchase intentions for (a) brick-and-mortar stores, (b) catalogs, and (c) the Internet. Following a pre-testing, a Computer-Assisted Telephonic Interview (CATI) was utilized for data collection with 500 multi-channel consumers. Structural equation modeling revealed that multi-channel consumers perceive important retail attributes differently across the three channels (i.e., brick-and-mortar stores, catalogs, and the Internet). Consumers perceived risks in personal security or buying private merchandise while shopping in stores. Consumers shopped clothing items via the Internet due to access to a variety of items and convenience-related attributes. Additionally, consumers who perceived higher level of cost tended t...
The Effects of Valvular Regurgitation on Thermodilution Ejection Fraction Measurements

Through the use of thermodilution principles and rapid response thermistors, it is now possible to measure right ventricular ejection fractions serially in patients. However, to our knowledge, the extent to which tricuspid regurgitation affects the accuracy of thermodilution ejection fraction measurements has not been quantified. The purpose of this study was to compare actual and thermodilution ejection fraction measurements in an in vitro model of tricuspid regurgitation over a wide range of ejection fractions. Stepwise perforation of the inlet valve resulted in regurgitant fractions ranging from 4 to 40 percent. At each increment of inlet valve regurgitation, triplicate sets of thermodilution (EFthermo) ejection fraction measurements were obtained and compared with actual ejection fractions (EFactual). The mean difference between EFactual and EFthermo significantly increased with 8 percent regurgitation and significantly increased with greater increments of inlet valve regurgitation. EFthermo consistently underestimated EFactual over the entire range of regurgitant values. Linear regression analysis revealed a significant correlation between EFactual and EFthermo for all degrees of regurgitation; however, the correlation coefficient significantly declined from control valves with 13 percent regurgitation and declined further with 33 percent regurgitation. Qualitative classification of the inlet valve regurgitation into mild, moderate, and severe regurgitation was performed using pulsed Doppler echocardiography. Mild inlet valve regurgitation resulted in a significantly increased difference between EFactual and EFthermo from control values. A significant increase in the difference between EFactual and EFthermo was observed with both moderate and severe regurgitation. In summary, thermodilution underestimated actual ejection fraction in a direct linear relationship to the degree of inlet valve regurgitation. Thus, in the presence of tricuspid regurgitation, this method may still be useful in serially measuring changes in right ventricular ejection fraction.
A computer-based test battery for the assessment of static and dynamic spatial reasoning abilities

A battery of 10 computerized tests of spatial ability is described. It includes 5 tests that require reasoning about static spatial displays and 5 tests that require reasoning about dynamically displayed spatial information. An integrated software package for task presentation and data analysis is described, along with a summary of results from a validation study comparing performance on the computer-based tests with performance on standardized paper-and-pencil tests of spatial abilities. Finally, research applications of the current battery are discussed.
The Helping Relationship Inventory: A Clinical Appraisal

The Helping Relationship Inventory (HRI) is a newly developed measure of the strength of the helping relationship. It is designed for use by social workers and their clients in a variety of helping...
Adsorption of natural organic matter (NOM) on iron oxide: Effects on NOM composition and formation of organo-halide compounds during chlorination

A large fraction of the natural organic matter (NOM) in potable water sources can be extracted by adsorption onto iron-oxide-coated sand (IOCS). In this research, two water sources were characterized with respect to their hydrophobic/hydrophilic fractionation, their 13C NMR and UV absorbance spectra and their reactivity with chlorine, before and after the waters were contacted with IOCS. The IOCS preferentially adsorbs acidic fractions of NOM and NOM molecules that are enriched in aromatic and carboxylic carbon. The yield of chloro-organic compounds (quantified as total organo-halide) produced upon chlorination of the NOM or its major fractions correlates with the specific absorbance (As) at 254 nm. IOCS may be useful for removing disinfection by-product (DBP) precursors from potable waters and/or as a medium for NOM accumulation.
Assessment of Some Integrated Cooling Mechanisms for an Active IPEM

With the growing demands on the performance, cost, and advances in packaging and interconnection technology, three-dimensional (3D) packaging provides higher density packaging. On the other hand, thermal management of the 3D package becomes a very important issue. This paper assesses the various possibilities of integrated thermal management for integrated power electronics modules (IPEMs).Copyright © 2004 by ASME
Clinical and experimental utility of refundable deposits.

Abstract The purpose of this study was to investigate the effects of a refund system on court-referred clients' adherence to the attendance and data-collection requirements of a program contract. Male and female clients admitted to a group treatment program for driving under the influence of alcohol were or were not required to place a $50 refundable deposit at the beginning of treatment. The results showed that subjects in the refundable deposit groups had fewer unexcused absences and were more efficient in returning data-collection forms, suggesting that deposits have considerable utility in a clinical/research setting.
Assessment of surgical septal myectomy by real-time 3-dimensional transesophageal echocardiography.

The left ventricular outflow tract (LVOT) is a 3-dimensional structure. Consequently, 2-dimensional transesophageal echocardiography (2D TEE) will never be able to truly assess this structure’s dimensions during the cardiac cycle. While Doppler technology can provide the imager with indirect information regarding the adequacy of septal resection (reduction in pressure gradient, loss of turbulent flow distal to the obstruction), only 3-dimensional imaging is capable of directly quantifying the adequacy of resection. The authors report the use of realtime 3-dimensional TEE (RT 3D TEE) imaging to assess the adequacy of surgical septal myectomy.
Discrete RNA libraries from pseudo-torsional space

The discovery that RNA molecules can fold into complex structures and carry out diverse cellular roles has led to interest in developing tools for modeling RNA tertiary structure. While significant progress has been made in establishing that the RNA backbone is rotameric, few libraries of discrete conformations specifically for use in RNA modeling have been validated. Here, we present six libraries of discrete RNA conformations based on a simplified pseudo-torsional notation of the RNA backbone, comparable to phi and psi in the protein backbone. We evaluate the ability of each library to represent single nucleotide backbone conformations, and we show how individual library fragments can be assembled into dinucleotides that are consistent with established RNA backbone descriptors spanning from sugar to sugar. We then use each library to build all-atom models of 20 test folds, and we show how the composition of a fragment library can limit model quality. Despite the limitations inherent in using discretized libraries, we find that several hundred discrete fragments can rebuild RNA folds up to 174 nucleotides in length with atomic-level accuracy (<1.5 A RMSD). We anticipate that the libraries presented here could easily be incorporated into RNA structural modeling, analysis, or refinement tools.
Sequential estimation of the mean of an exponential family in three stages

Abstract This paper provides a three-stage sequential procedure for estimating the mean of an exponential family of probability distributions with a weighted squared error loss and a fixed cost for each observation. The procedure is shown to be asymptotically optimal to second order, for a general class of estimators of the mean.
Orthogonal wavelets in nonlinear speckle reduction for improved target recognition

We propose a novel orthogonal wavelet-based approach to reduce speckle in synthetic aperture radar and gray-scale images for better automatic target recognition applications. We also analyze different image metrics using different thresholding and image data compression techniques.
Significance of stress transfer in time‐dependent earthquake probability calculations

[1] A sudden change in stress is seen to modify earthquake rates, but should it also revise earthquake probability? Data used to derive input parameters permit an array of forecasts; so how large a static stress change is required to cause a statistically significant earthquake probability change? To answer that question, effects of parameter and philosophical choices are examined through all phases of sample calculations. Drawing at random from distributions of recurrence-aperiodicity pairs identifies many that recreate long paleoseismic and historic earthquake catalogs. Probability density functions built from the recurrence-aperiodicity pairs give the range of possible earthquake forecasts under a point process renewal model. Consequences of choices made in stress transfer calculations, such as different slip models, fault rake, dip, and friction are tracked. For interactions among large faults, calculated peak stress changes may be localized, with most of the receiving fault area changed less than the mean. Thus, to avoid overstating probability change on segments, stress change values should be drawn from a distribution reflecting the spatial pattern rather than using the segment mean. Disparity resulting from interaction probability methodology is also examined. For a fault with a well-understood earthquake history, a minimum stress change to stressing rate ratio of 10:1 to 20:1 is required to significantly skew probabilities with >80–85% confidence. That ratio must be closer to 50:1 to exceed 90–95% confidence levels. Thus revision to earthquake probability is achievable when a perturbing event is very close to the fault in question or the tectonic stressing rate is low.
The Perilipin homologue, Lipid storage droplet 2, regulates sleep homeostasis and prevents learning impairments following sleep loss

Extended periods of waking result in physiological impairments in humans, rats, and flies. Sleep homeostasis, the increase in sleep observed following sleep loss, is believed to counter the negative effects of prolonged waking by restoring vital biological processes that are degraded during sleep deprivation. Sleep homeostasis, as with other behaviors, is influenced by both genes and environment. We report here that during periods of starvation, flies remain spontaneously awake but, in contrast to sleep deprivation, do not accrue any of the negative consequences of prolonged waking. Specifically, the homeostatic response and learning impairments that are a characteristic of sleep loss are not observed following prolonged waking induced by starvation. Recently, two genes, brummer (bmm) and Lipid storage droplet 2 (Lsd2), have been shown to modulate the response to starvation. bmm mutants have excess fat and are resistant to starvation, whereas Lsd2 mutants are lean and sensitive to starvation. Thus, we hypothesized that bmm and Lsd2 may play a role in sleep regulation. Indeed, bmm mutant flies display a large homeostatic response following sleep deprivation. In contrast, Lsd2 mutant flies, which phenocopy aspects of starvation as measured by low triglyceride stores, do not exhibit a homeostatic response following sleep loss. Importantly, Lsd2 mutant flies are not learning impaired after sleep deprivation. These results provide the first genetic evidence, to our knowledge, that lipid metabolism plays an important role in regulating the homeostatic response and can protect against neuronal impairments induced by prolonged waking.
Management commitment to the ecological environment and employees: Implications for employee attitudes and citizenship behaviors

In this article, we examine the implications of perceived management commitment to the ecological environment for employee attitudes and behaviors. Following deontic justice theory, which suggests that individuals are capable of feeling and expressing moral outrage when others are treated poorly, even if such treatment has no direct implications for themselves, we expected that employee attitudes and behaviors would be related to perceived organizational treatment of the environment. At the same time, we expected that these reactions would be moderated by how employees themselves were treated by the organization, in the form of perceived organizational support. In a study of employees and supervisors in a textile firm in Turkey, the results indicate that perceived organizational support moderated the effects of management commitment to the environment on organizational justice, organizational commitment and organizational citizenship behaviors targeting the environment.
Impairment and disability in persons with MS: do functional performance or functional limitations matter?

Persons with multiple sclerosis (MS) often demonstrate impairment in cardiorespiratory and musculoskeletal systems that may be associated with functional performance, functional limitations, and disability limitations. This study examined such relationships in persons with MS using Nagi’s disablement model and its subsequent conceptual modifications. The sample included 63 persons with MS (75% relapsing–remitting MS, median EDSS = 4.0, and mean MS duration = 13.1 years) who underwent measurements of aerobic fitness and muscular strength (i.e. impairment), functional performance, functional limitations, and disability limitations. The data were primarily examined using path analysis in Mplus 7.0. Our final model provided an excellent fit for the data (χ² = 0.67, df = 3, p = 0.88, SRMR = 0.01, and CFI = 1.00). The final model indicated that aerobic fitness and muscular strength were indirectly associated with disability limitations in persons with MS through a pathway that included functional limitations (i...
Systemin potentiates the oxidative burst in cultured tomato cells

Plants that have been wounded by insects or other herbivores may be more susceptible to infection by adventitious microbes. Wound-induced signal molecules, which serve to induce responses in the plant that retard further feeding, might also act to prepare a plant for possible pathogen attack. We have examined the effect of a wound-generated systemic messenger (systemin) on a pathogen-stimulated defense-response marker, the oxidative burst. We observed that neither systemin nor its inactive analog (A-17) was able to directly induce H2O2 biosynthesis in suspension-cultured tomato (Lycopersicon esculentum L.) cells, regardless of the duration of exposure of the cells to the two peptides. Similarly, neither systemin nor A-17 was capable of modifying an oligogalacturonide-elicited oxidative burst, as long as elicitor addition occurred within minutes of treatment with systemin or A-17. In contrast, preexposure of the cell cultures to systemin (but not to A-17) led to a time-dependent enhancement of the oligogalacturonide-elicited oxidative burst. By 12 h of exposure, the H2O2 biosynthetic capacity of systemin-treated cells exceeded that of the control cells by a factor of 16 ± 2. A similar up-regulation by systemin of a mechanically stimulated oxidative burst was also observed. Because the systemin-induced augmentation in oxidant synthesis is quantitatively prevented by coincubation with 2 μm cycloheximide, and because the oxidative burst of oligogalacturonic acid-elicited control cells (no systemin exposure) is unaffected by preincubation with cycloheximide, we conclude that systemin enhancement of the tomato-cell oxidative burst requires protein synthesis.
Effect of Precipitation Hardening on the Superconducting Properties of Aluminum

The effect of heat treatment on the superconducting properties of a precipitation hardening Al-Mg-Si alloy has been studied in some detail by ballistic induction techniques. The alloy (Alcoa 6063) contains approximately 1.1% ${\mathrm{Mg}}_{2}$Si which precipitates from a supersaturated solid solution to an extent controlled by the heat treatment. The precipitation process results in marked changes in the mechanical properties of the alloy, and equally pronounced changes are found to occur in the superconducting behavior. For heat treatments which produce mechanical properties similar to those of pure Al, the superconducting properties of the alloy are found to be substantially the same as pure Al. Heat treatment to the condition of maximum hardness depresses the critical field of the alloy about 8 gauss below that of pure Al, the effect being closely similar to that expected for the application of hydrostatic pressure. In conditions of intermediate hardness pronounced hysteretic effects are observed. It is proposed that the observed changes arise from coherency stress around the Guinier-Preston zones which describe the aggregation of Mg and Si atoms in the early stages of precipitation.
Artifactual effects of hypernatremia and hyponatremia on red cell analytes measured by the Bayer H*1 analyzer.

Abstract— Hypernatremia in two cats and hyponatremia in a dog were associated with artifactual changes in red blood cell (RBC) indices and hematocrit (HCT) determined on a Bayer H*1 hematology analyzer. The RBC cytograms and histograms revealed a population shifted towards macrocytic, hypochromic RBC in the hypernatremic cats, and towards microcytic, hyperchromic RBC in the hyponatremic dog. Reference intervals for the difference between manual packed cell volume (PCV) and analyzer-derived HCT in normonatremic dogs, cats and horses were established. The difference between PCV and HCT was outside the reference values for all three patients. Quality control measures, such as measuring PCV, and reviewing cytograms and histograms, are essential for detecting spurious changes in automated hematology measurements caused by abnormalities in serum sodium concentration and osmolality.
Nonmarine ostracode shell chemistry from ancient hohokam irrigation canals in central Arizona: A paleohydrochemical tool for the interpretation of prehistoric human occupation in the North American Southwest

Environmental archaeology studies on samples from an agricultural context provide information that may be used to answer questions of climatic vs. human impact on Hohokam prehistory. Hohokam irrigation systems were fragile and subject to episodic damage and destruction. Ostracodes are sensitive to hydrochemical changes. Their fossil record in Hohokam canals can provide useful data to understand human/environment relationships in the past. Low-Mg calcite ostracode carapaces form in thermal and chemical equilibrium with the host water. Magnesium and strontium are commonly incorporated into the shell as trace elements, which can be used to track paleotemperature and paleosalinity variations. Thus, fossil ostracodes reflect the water chemistry in which the valves were precipitated. Valves of Limnocythere staplini, Candona patzcuaro, and Cypridopsis vidua were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) to determine the Mg/Ca and Sr/Ca ratios. Trace element data were used to reconstruct the canal water chemistry and to propose paleoclimatic and human-impact hypotheses for environmental change. The ostracode record shows some evidence of a progressive salinization process between A. D. 1025 and 1425 that may be the result of human disturbance; this inference is supported by independent evidence from geographic, palynologic, and dendroclimatologic data. In addition, two major climatic events, large enough not to be masked by human activity, were also recorded by ostracode geochemistry: a flood between A. D. 855 and 910, another flood prior to A. D. 1350, and a drought between A. D. 1365 and 1425. © 1994 John Wiley & Sons, Inc.
Anatomy-based transmission factors for technique optimization in portable chest x-ray

Portable x-ray examinations often account for a large percentage of all radiographic examinations. Currently, portable examinations do not employ automatic exposure control (AEC). To aid in the design of a size-specific technique chart, acrylic slabs of various thicknesses are often used to estimate x-ray transmission for patients of various body thicknesses. This approach, while simple, does not account for patient anatomy, tissue heterogeneity, and the attenuation properties of the human body. To better account for these factors, in this work, we determined x-ray transmission factors using computational patient models that are anatomically realistic. A Monte Carlo program was developed to model a portable x-ray system. Detailed modeling was done of the x-ray spectrum, detector positioning, collimation, and source-to-detector distance. Simulations were performed using 18 computational patient models from the extended cardiac-torso (XCAT) family (9 males, 9 females; age range: 2-58 years; weight range: 12-117 kg). The ratio of air kerma at the detector with and without a patient model was calculated as the transmission factor. Our study showed that the transmission factor decreased exponentially with increasing patient thickness. For the range of patient thicknesses examined (12-28 cm), the transmission factor ranged from approximately 21% to 1.9% when the air kerma used in the calculation represented an average over the entire imaging field of view. The transmission factor ranged from approximately 21% to 3.6% when the air kerma used in the calculation represented the average signals from two discrete AEC cells behind the lung fields. These exponential relationships may be used to optimize imaging techniques for patients of various body thicknesses to aid in the design of clinical technique charts.
Development of cellular tolerance to lethality and analgesia concurrent with physical dependence following repeated oral administration of LAAM

Following the repeated oral administration of l-alpha-acetylmethadol (LAAM) employing a dose (28 mg/kg per day) shown to induce its own metabolism by three- to four-fold, mice exhibited a rapid development of cellular tolerance and physical dependence which correlated on a temporal basis with this self-induction of LAAM metabolism. Evidence of cellular tolerance included significant elevations in the LAAM oral LD50, LAAM ICV (intracerebroventricular) LD50, LAAM oral AD50 and the LAAM ICV AD50 following repeated administration of this narcotic. Since the ICV parameters and the morphine AD50 were elevated over water control values, cellular tolerance appeared to play an important role in explaining the elevations noted for the oral parameters because the former were not influenced by changes in the rate of LAAM metabolism. Moreover, SKF-525A, a microsomal enzyme inhibitor, had little effect on the LAAM oral LD50 and the LAAM oral AD50, further indicating a minor role for dispositional tolerance. It is concluded that the induction noted for repeated oral LAAM administration most likely is responsible for generating more potent metabolites which in turn act to produce the cellular tolerance and physical dependence in these mice through constant exposure of the CNS.
The Electrolyte and Water Secretion Mechanism

The currently accepted salivary gland secretion model describes the process of fluid secretion as the coordinated action of water and ion channels and transporters. The secretion of electrolytes and water by salivary glands is thought to be activated by an agonist-induced increase in the intracellular free [Ca2+] and to be driven by transepithelial chloride movement. The Cl- transport is supported by upregulation of several ion transporters, K+ and Cl- channels, and the Na+/K+-ATPase. This review will focus on the details of the transport mechanisms as well as recent developments in confirming the molecular identities of the involved transporter and channel proteins.
Halogenation of polyethylene. I. Bromination of single crystals

It has been demonstrated that the fold surfaces of polymers can be specific towards chemical attack, if the reaction is mild and nondestructive of the fold. Bromination of suspensions of single crystals of polyethylene in carbon tetrachloride has been shown to be such a system. This chemical modification of a fold surface is a powerful means of extending the applications of the physical methods available. Several methods were used, among them DTA, DSC, infrared spectroscopy and small-angle x-ray diffraction. Experimental results from these methods lead to the following conclusions. (a) Bromination takes place preferentially at the folds and is consistent with a regular adjacent reentry fold model. (b) Annealing of these brominated crystals demonstrates the major role played by the crystal surface in this process. (c) The preparation and properties of a novel copolymer system has been demonstrated. It is felt that this copolymer system may prove a useful addition to those systems presently available.
Ultraviolet light‐induced photorelaxation of agonist‐contracted rabbit aorta: Further characterization and the estimation of drug‐receptor rate constants

Isolated strips of rabbit thoracic aorta, contracted to a steady-state isometric tension by measured doses of α-adrenoceptor agonists, exhibit a transient loss in tension when exposed to a flash of ultraviolet light. This response consists of an initial decrease in tension followed by a spontaneous restoration to equilibrium tension. The time course of the return to equilibrium from maximum relaxation is a biphasic exponential, resolvable into a fast phase and a slow phase. Previous work has shown that the fast phase of recovery is drug-independent, but that the slow phase of recovery is drug-dependent; i.e., the rate of return to equilibrium tension is unique for each agonist used to produce the initial contraction. When a system in equilibrium is perturbed in a manner such as this, the return to equilibrium is characterized by a time constant that is a function of the drug concentration. A plot of this time constant against drug consentration yields a straight line of slope and y-intercept equal to the forward and reverse rate constants, respectively, of the chemical reaction. In this study, equilibrium perturbation by UV light was used to determine the forward and reverse rate constants (k1 and k2) of the drug-receptor interaction and the dissociation constants (KA = k2/k1) of each of three α-adrenoceptor agonists, norepinephrine, phenylephrine, and methoxamine. The values of KA reported here for all three agents and for different degrees of passive stretch (0.25-g and 10-g preload for norepinephrine, 10-g preload for phenylephrine and methoxamine) are not significantly different from the corresponding values reported using the method of partial irreversible blockade of receptors. These findings are compatible with the hypothesis that the radiation disrupts the drug-receptor equilibrium. Regardless of mechanism, however, the photorelaxation phenomenon may provide an additional tool for classifying vasoactive compounds.
Five grams of coke: Racism, moralism and White public opinion on sanctions for first time possession

A path-analytic model was used with a national probability sample of White Americans to examine the effects of moralism, attributions of blame, beliefs about racial group use of cocaine, beliefs about racism, and beliefs about the effectiveness of law enforcement on judgments about appropriate sanction for being caught for the first time with 5 g of cocaine. As predicted severity of sanction was directly related to judgments about the morality of addicts and attributing blame for addiction to addicts. Though the predicted direct relationship between racism and severity of sanction was not found, a strong indirect relationship was found as racism operated through morality, blame, and beliefs about racial group use of cocaine. Though counter-intuitive, sentence severity was not predicted by judgments about the effectiveness of law enforcement policy. Finally, these results were significant while controlling for conservative ideology, which was found to be positively related to racism, the attribution of blame for addiction to the addict, and the belief that addiction reflects the moral character of the addict. This study produced empirical support for a relationship between a moralistic doctrine and control attitudes. This is congruent with assumptions in reviewed literature on theoretical underpinnings of substance abuse policies in the United States. Also, consistent with the literature was the finding that racist sentiments influence perceptions of morality as they relate to addiction and policies established to address drug use. Furthermore, this study provides empirical evidence that racism and moralism can influence support for policies regardless of their perceived effectiveness.
Spatial and temporal distributions of Martian north polar cold spots before, during, and after the global dust storm of 2001

[1] In the 1970s, Mariner and Viking observed features in the Mars northern polar region that were a few hundred kilometers in diameter with 20 μm brightness temperatures as low as 130 K (considerably below CO2 ice sublimation temperatures). Over the past decade, studies have shown that these areas (commonly called “cold spots”) are usually due to emissivity effects of frost deposits and occasionally to active CO2 snowstorms. Three Mars years of Mars Global Surveyor Thermal Emission Spectrometer data were used to observe autumn and wintertime cold spot activity within the polar regions. Many cold spots formed on or near scarps of the perennial cap, probably induced by adiabatic cooling due to orographic lifting. These topographically associated cold spots were often smaller than those that were not associated with topography. We determined that initial grain sizes within the cold spots were on the order of a few millimeters, assuming the snow was uncontaminated by dust or water ice. On average, the half-life of the cold spots was 5 Julian days. The Mars global dust storm in 2001 significantly affected cold spot activity in the north polar region. Though overall perennial cap cold spot activity seemed unaffected, the distribution of cold spots did change by a decrease in the number of topographically associated cold spots and an increase in those not associated with topography. We propose that the global dust storm affected the processes that form cold spots and discuss how the global dust storm may have affected these processes.
Achievable Rates for Pilot-Assisted Transmission over Rayleigh Fading Channels

In this paper, transmission over a single-input, single-output, time-varying Rayleigh flat fading channel is considered. Time variations of the channel are modeled by a Gauss-Markov process. It is assumed that neither the transmitter nor the receiver has prior channel state knowledge. The transmitter employs pilot-assisted transmission and periodically sends training symbols for the receiver to estimate the channel. Information rates achieved by binary phase-shift keying modulation are maximized by finding the optimal pilot signal transmission period and optimal training power allocation. Both fast and slow fading conditions are studied. A significant improvement in achievable rates has been shown when training power adaptation is performed. If the power of both training and data symbols are adapted, it is shown that achievable rates can further be increased especially at low SNR values.